Ponds attract wildlife to the garden and can provide an oasis of life for aquatic organisms, but not all visitors are as welcome as others…
WORDS: JEREMY GAY
We all love wildlife and, unlike an aquarium, a pond can attract visitors that are free to travel to and from the water at will. But which are desirable and which are a downright nuisance?
It all comes down to whether you want a fish pond or a wildlife pond — the two are very different things, and what benefits one may not benefit the other.
If you have fish in your pond they must be your number one welfare priority. Unlike insects, amphibians and birds, they can’t leave and that makes them sitting ducks for all manner of predators. What makes it worse is that we then handicap them with bright colours, fat bodies and a lack of hiding places or distance to escape to.
Here’s the list of regular offenders:
Public enemy number one has got to be the heron. These lanky grey birds will frequent your pond before you get up in the morning, and with no one about, having your pond close to your house is no defence either. Once they’ve found your pond they can more or less empty it of small to medium sized fish, and stab and injure those too large to swallow.
- You can’t harm them as they are protected (although you should never think of doing that anyway).
- Netting can be effective but it would have to be fine, taut and effectively cover all areas.
- Fishing line placed strategically around the pond on stakes can prevent a bird from landing or wading in. Wire can also be placed at pergola height to prevent flying down to the pond.
- Plastic herons are the most commonly practiced defence, although we have heard many stories of owners seeing a live heron feeding next to their plastic one!
- Very visible fish in the pond will be targeted first and are easy to spot from the air. Try mottled Shubunkins instead of bright red goldfish, but failing that, netting is the only way.
I believe that otters have as much right to the waterways as we do, but I can imagine how gutting it would be to find your prize Koi massacred of a morning. Otters are well and truly back, and gorging themselves on ornamental fish all over the UK.
- Netting a pond won’t work, as otters will crawl under it. Instead, you’ll need a wooden frame with no gaps, and a wooden frame with wire mesh on top, with a latch or even a padlock on it.
- Build a waist-high wall or fence around the whole pond, or opt for a raised, formal pond with the frame and mesh top.
Rats are great swimmers, and ponds provide lots of feeding opportunities for them, including eating your fish food. They are a menace though, chewing through pond liners and weeing in the water, spreading Weil’s disease to humans, which at best is flu like but can be much worse. They can predate on other animals, too — I’ve seen them taking baby ducks, so they may have a go at a sluggish fish.
- Don’t leave buckets of pond food poolside, and don’t leave uneaten food on or around the pond. Having bird feeders near the pond may attract them, too.
- Brick-built raised ponds with no exposed liner and no subterranean access to the liner either, solved by a concrete base.
- Small gauge wire mesh.
One of my all time favourite birds, a kingfisher is a wonderful sight. Even the most staunch pondfish breeder surely can’t deny such a handsome and diminutive bird the odd snack, so I say them let them stay and enjoy the moment. They’ll only predate on small, minnow sized fish anyway.
- You are unlikely to have kingfishers if your pond is nowhere near a river or stream — so you could move!
- If you want to say ‘bah humbug’ to ever having a kingfisher visit, or your fry happen to be tategoi or tosakin worth a few hundred quid a pop, simply cover the water with fine netting or a plastic corrugated lid.
Damsel and dragonflies
Only dangerous to your fish when they are fry, damsel and dragonfly larvae are voracious predators which may take tadpoles and baby fish.
- Don’t have any plants and heavily filter the pond. A clinically clean Koi pond with large hungry Koi is unlikely to support any dragonfly larvae, as the fish will eat them.
- Remove all plants and if you are particularly wanting to raise Koi and goldfish fry, very small gauge insect netting will keep the adult insects from laying their eggs in the water. But really, the visual benefit of adults often outweighs the few fry you could lose to their larvae.
These 'sea' birds travel inland the world over in search of food, and can gobble up fish on an industrial scale. If a cormorant lays eyes on your pond and can access it, your fish are in trouble.
- Stop the bird from flying in, perching and diving into the pond.
- High level netting or wire to prevent flight in, and very coarse netting, securely fastened to prevent the birds taking fish. Make sure the net gauge is fine enough to prevent the beak, head or neck from poking through it and grabbing or stabbing fish.
Wild ducks finding your ornamental pond is a wonderful thing for all of about five minutes. They get all excited, wade in and start to dabble and bathe. If you have a waterfall they may play in it — and even climb up and ride back down it! But by the time you’ve rushed to grab that camera, the idyllic scene will have turned into carnage as the ducks start to demolish all your pond plants, uproot the soil in the plant baskets and poo and drop soil into the water, making an instant mess. Your fish will scatter too.
- You need to prevent ducks from both flying in and entering the pond.
- Net the pond high up to prevent ducks flying in, and also at water level to prevent them from wading in. And don’t be tempted to feed the ducks — they will come back.
During heat waves, grass snakes may take to the water to cool down. They can hold their breath and swim underwater, and are reported to occasionally predate pond fish.
- A grass snake won’t wipe out a pond like a heron or otter, and if you have the kind of undergrowth that encourages grass snakes, you’ll probably have frogs and toads too, which the snakes will eat instead. The defence is to prevent access for the snake.
- Why would you want to stop grass snakes from thriving in your garden? Native reptiles are so cool and grass snakes are not in the least bit dangerous. But if you want to stop them, a waist high brick built raised pond will do it. They tend to prefer ground level water with poolside vegetation to retreat to.
In my retail days we regularly fought a very clever crow, which could tell the time and would wait until closing time, before it swept in. Its favourite prey were 5–7.5cm/2–3in Comet goldfish which it would pick from the water, always leaving the head for us in the morning as evidence (herons and cormorants always swallow fish whole, head first).
- You’ll be OK with foot-long fish. Understocking the pond will also not so be as tempting. Feed fish away from the pond edge, as the crow can’t reach very far.
- Net your pond or use a frame and cover, which you can hinge up and down depending on whether you are in the garden or not.
A pretty menacing, quite large aquatic insect, the water scorpion can and does consume large tadpoles, baby newts and pond fish fry.
- The water scorpion will favour sluggish, weedy areas where it can hide and ambush fish, and where smaller fish like to hang out.
- Don’t introduce any plants, stock large fish only, which will eat them, and regularly vacuum your pond walls and base.
I’ve never seen a wild otter, but I saw plenty of mink in the waterways when I was growing up. Mink are indiscriminate pond fish killers and should be treated in the same way as otters. If a mink finds your pond all your fish are in trouble — and chickens if you keep them, too.
- As with the otter, you need to totally block entry to your pond and even small gaps or holes in netting will allow easy entry.
- Brick built raised pond with strong wire on gap proof, lift-proof frame or a strong metal grid.
Movie aliens and monsters have nothing on the octopus when it comes to weirdness. And, so long as you can meet their needs, these animals make intelligent, interactive pets.
WORDS: DAVE WOLFENDEN
Frankly, you’d be hard pressed to make anything up as bizarre as an octopus. They lack a skeleton, but are extremely strong; they suck their liquidised prey through a hole in the middle of their brain; their eight arms are covered in independently-controlled suckers;
they have three hearts, blue blood and can change the colour and texture of their skin.
Octopuses are molluscs, belonging to a group known as the cephalopods (meaning ‘head foot’), making them relatives of squids and cuttlefish. They possess a muscular ‘cloak’ known as a mantle which covers the internal organs, and have a system of jet propulsion thanks to a structure known as the siphon. Rapidly forcing water through the siphon allows for rapid movement. As the shell has been reduced either entirely, or at least is now reduced to vestigial fragments in the mantle, they’re quite vulnerable, so octopuses have developed this ability to evade predators as a defence mechanism. It may be assisted with a puff of ink (which can act as a ‘smoke screen’, or perhaps act as a diversionary tactic to distract a pursuing predator).
To avoid being detected in the first place, these amazing animals adopt cryptic behaviours, and are able to change the colour of their skin via pigment-filled sacs called chromatophores, as well as its texture, thanks to structures known as papillae located across the body.
Octopuses are intelligent, with a natural curiosity to explore any part inside or outside of their aquarium; as a result, they’re interactive, and can assume full pet status.
Octopuses in the aquarium
It is possible to successfully maintain octopuses at home, but they require some key aspects of husbandry if they are to thrive.
Size: Octopuses can vary wildly in size, so it’s difficult to give recommendations as far as tank volumes go, but I’d suggest that the animal needs to have sufficient room to explore, and you’ll need to really judge each specimen on its own merits. If the length of the aquarium is around four times the arm span of the animal, this is a reasonable size.
Filtration and life support: Octopuses are messy feeders with a big appetite, so they generate a lot of solid waste. Therefore, mechanical filtration needs to be able to cope adequately, and the media should be cleaned or replaced frequently. An octopus system will have a relatively high bioload, thanks to the animal’s food, and the ammonia generated by the octopus itself, so efficient biological filtration is essential. Octopuses require optimal oxygen saturation, so ensure adequate turnover. This is important thanks to the relatively inefficient respiratory pigment haemocyanin. They’re not too fussy about nitrate, but aim for zero ammonia and nitrite.
A skimmer will help with ensuring oxygen saturation, as well as pulling out as much waste-laden skimmate as possible. Ozone isn’t tolerated well by cephalopods, so don’t use it.
Water: The quality of the salt water you provide is crucial for keeping octopuses, and they don’t do well in certain budget ‘fish-only’ brands of salt. Use RO water for make-up, and opt for a good, reef-quality salt to be on the safe side. Copper and other metals are a big problem for octopuses, so this is very important to observe. And employ chemical filtration courtesy of activated carbon at all times.
Aquascaping: Most of the octopus species available in the trade are from heterogeneous rocky environments, so replicating this habitat is essential if the animal is to feel secure, exhibit its natural behaviour, and display well. Provide lots of nooks and crannies for the octopus to explore.
Lighting: Your octoquarium should have sufficient lighting to see the animal, of course, but many species won’t tolerate excessively bright illumination. In fact, some octopuses are nocturnal, so you won’t see these until ‘lights out’ generally, although they can adapt to a certain extent.
Enrichment is very important for the long-term health and welfare of octopuses. There are various things which you can do to provide stimulation for the animal. Try randomising feed times, making your octopus work for its food, and simply interacting with it — you don’t have to overdo things, but get creative.
Octo-proof your set-up
As escape artists, octopus would make Houdini blush. As they have no bones or shells to get in the way, they can squeeze their muscular, flexible bodies through the tiniest of holes — it’s as if they can turn themselves into liquid and pour through the gap. And given a chance, they will. Exploration is irresistible to them. Leave them in an open-topped tank, and you’re as good as asking them to leave.
Therefore, a tight-fitting lid is an absolute must. This could be made of glass, or it may incorporate mesh (obviously of the plastic, non-toxic variety), but crucially it must have small enough gaps to prevent escape. This obviously varies according to species or size of individual, but in some cases even a few mm is enough for them to get through. Bear in mind, too, that they’re strong, so any lid needs to be firmly fixed into place to prevent it from being pushed up.
Some public aquariums use wide bands of Astroturf to line the top of their octopus holding tanks to prevent escape — the octopus can’t grip the material properly. However, it’s not really a practical solution for the home system.
Octopuses are extremely curious animals, and it’s vital to ensure that any equipment which could harm them, such as heaters and filter or pump inlets, are well out of reach. Some ingenuity might be necessary to octo-proof any overflows and weirs.
Octopuses are voracious predators, with feeding facilitated by a parrot-like beak and a rasp-like radula, used to macerate their prey; they also possess venom glands used to immobilise the victim. They need to be fed regularly (daily or every other day); provide thawed crustaceans (crabs or prawns) or appropriately-sized fish. Octopuses adapt well to accepting frozen food, and this is preferable. However, they may need to have it presented to them on a feeding stick to get them used to it.
Octopuses generally don’t do well with conspecifics, thanks to cannibalistic and aggressive tendencies, and only a few species can be kept in groups. All the commonly-available species in the hobby should be kept singly. As for housing them with fish — it’s a no-no. Larger species may try and eat the octopus, while the octopus will make short work of smaller species. Many corals and anemones will sting the cephalopod’s sensitive skin, and the octopus will predate upon mobile inverts and clean-up crew. On balance, a dedicated species system is the way to go.
Live fast, die young
Octopuses don’t tend to have long lifespans, which can be an issue. Some small tropical species may live for no longer than six months after hatching, and individuals may be several months old when they make their way into the trade. For a medium-sized species such as the Common octopus, Octopus vulgaris, two years is good going, and with the Giant pacific octopus, Enteroctopus dofleini, which lives in very cold water, you’re looking at just five
years — tops.
A male octopus may suddenly die without apparent warning, but a female will naturally undergo a process known as senescence. She lays eggs (which may be either fertile or infertile depending on whether she has mated), and then spends the rest of her short life tending to them. She’ll refuse food and slowly lose condition, possibly over several weeks.
Senescence can be a distressing phenomenon to watch, but it’s a fact of octopus life — you have been warned.
We don’t know an awful lot about octopus disease. Occasionally, parasites may be a problem, as can bacterial infections of the skin — but these should be left to a specialist vet to diagnose and treat if necessary.
Most health issues are primarily due to environmental factors: for example, ammonia spikes or metal pollution; or through boredom. Therefore, maintaining ideal water quality and a stimulating environment should reduce any potential health problems.
Beautiful — but deadly!
There is a genus of octopuses you’ll want to avoid. Get bitten by one of these, and you’re in for a world of hurt — and they’ve been responsible for deaths. I’m referring to the blue-ringed octopuses (genus Hapalochlaena), of which there are several species.
Blue rings tend to be small (with a span of only 10cm/4in maximum) and beautifully coloured, but they harbour bacteria in their salivary glands which synthesise tetrodotoxin (TTX). TTX is one of the most potent neurotoxins known, and according to survivors, the consequences of a bite sound terrifying, including paralysis.
Amazingly, these animals are imported; they’re not actually illegal to keep under DWA (Dangerous Wild Animals) licensing, but no responsible retailer will sell you one. I know of one dealer who was more than a little concerned when several blue rings were added into a shipment by the collector as a sort of ‘freebie’. Luckily, the dealer donated the animals to public aquariums able to house them.
4 octopus for the aquarium
Octopus offered for sale will often simply be labelled ‘Octopus sp.’ due to the challenges of conclusively identifying them. However, a few crop up frequently which can fairly easily be given an ID. For others, you’ll need a good book such as Mark Norman’s Cephalopods: a World Guide.
Scientific name: Octopus vulgaris (Oct-oh-puss vul-ga-riss).
Origin: Worldwide, across temperate and tropical seas.
Size: At least 60cm/24in span, and perhaps up to 1m/40in.
The Common octopus is frequently offered for sale in the hobby. The situation is a little confusing, as several species from a ‘complex’ are actually sold under these scientific and common names.
Scientific name: Octopus horridus (Oct-oh-puss ho-rid-uss).
The Octopus horridus complex comprises several Indo-Pacific species, and you’ll often encounter these. They tend to have long arms and adopt an extremely cryptic way of life. However, the escape abilities of these octopuses are second to none.
Scientific name: Octopus bimaculoides (Oct-oh-puss bi-mack-you-loy-deez).
Origin: Pacific Ocean.
Size: Up to 50cm/20in span.
Distinguished by the two eye-spot markings, this species is closely related to the larger O. bimaculatus.
Scientific name: Octopus cyanea (Oct-oh-puss sigh-an-ay-ar).
Size: Reaches nearly 1m/40in in span.
Due to its eventual size, this species will require a very large aquarium.
Mbuna are colourful, hardy cichlids that are easy to breed in the aquarium. But they’re also highly territorial fish, so get things wrong and you could have a blood bath. Here’s how to avoid a rocky horror…
WORDS: JEREMY GAY
Fishkeepers the world over struck gold with the introduction of the small colourful rock dwelling cichlids from East Africa’s Lake Malawi. The mbuna as they are known (pronounced mmm-boon-a or mu-boon-a,) are hardy, easy to keep, easy to breed, and widely available.
One qualification any aquarium fish needs to become really popular is colour, and mbuna deliver this in swathes. Yellow and orange are common mbuna colours but importantly, and rarely for any wild-type tropical fish is blue, and this is where the mbuna excel, with literally hundreds of bright blue species, which have tricked many an onlooker into thinking these totally freshwater fish are in fact marine.
Next is the number of species you can keep together. No other aquarium is capable of holding as many different species of fish per volume as a Malawi cichlid tank. An average mbuna community could hold 30 different species — a large tank 50 or more. You wouldn’t be able to keep 30 Central American species in one tank — it would be chaos — and even a community tank of fish from many different, very varied genera would struggle to hold that many because so many species need to be kept in groups of their own kind. This all adds to the overall appeal of mbuna.
Mbuna in nature
To keep mbuna at their best we must first look at how and where they live in nature. Mbuna are endemic to Lake Malawi in Africa’s Great Rift Valley — a 3,700-mile long trench created by the African tectonic plate tearing apart. Malawi is a gigantic crevice. It filled with river water and fish — and these then changed, evolved and adapted to suit their new, lacustrine environment.
And it’s big. Malawi is the ninth largest lake in the world and the second deepest, at 706m. Its 360 miles long, 50 miles wide and some 11,000 square miles in area. That’s bigger than Wales…
A lake of that size comes complete with waves, rocky cliffs and sandy beaches. Tales abound of early explorers mistaking it for an ocean, which let’s face it, you would.
Cichlids entered Malawi via its tributaries, with two tribes — the tilapiines and the haplochromines — taking up permanent residence there. Things got interesting for the haplochromines however, which went through “adaptive radiation” and today comprise around 1,000 species, which is about as many as live in the whole of the North Atlantic! This was great news for human populations who could then fish the lake for food, scientists who could study evolution — and us fishkeepers, who get to marvel over Malawi’s bountiful beauty in our home aquariums.
So think freshwater reef fish and you would be about right, as the colourful yellow and blue mbuna we keep bask in the clear blue, sunlit waters and live in and around the rocky outcrops. Cichlid paradise!
But the fascination doesn’t stop there, as the mbuna deliver a double whammy of appeal by way of how they breed. All the mbuna, and all the other haplochromines in Lake Malawi are maternal mouthbrooders, meaning that they lay eggs, which are then taken into the female’s mouth where they are incubated, hatched, and then finally spat out as fully formed fry.
This paid dividends for the early cichlid colonisers of the lake bed as even breeding females were not tied down to any one small patch for a month at a time and instead could be upwardly mobile, go forth and colonise. The uninitiated wouldn’t know that a female was with eggs or fry at all, and the males didn’t have to turn into giants who would then have to defend the fry against all comers, whether fish, bird or reptile.
Keep mature males and females together in the home aquarium and they will breed. And for many mbuna keepers the progeny can provide a useful supplemental revenue stream.
Keeping them at home
The good news about mbuna is that although there are so many species, they can all be kept in exactly the same way, eat exactly the same food, and once you have conquered keeping them for the first time you can pretty much keep any of them, as long as you observe the fundamentals.
Coming from such a large lake, the mbuna are used to clean, clear water, which is free of pollutants and rich in oxygen. In the aquarium this means they need lots of mechanical and biological filtration, plenty of water changes to keep nitrate at low levels and extra aeration by way of an airstone or Venturi outlet on a filter.
Next is the chemistry of the water. All that tectonic plate activity under the lake has meant that Malawi is very rich in minerals, which give it a high pH, KH (carbonate hardness,) and GH (general hardness). Those with scaled-up kettles and hard tapwater will do really well with mbuna — these aren’t fish for soft, acidic water conditions. So it’s no to reverse osmosis water without adequate amounts of Malawi cichlid salts first being added, and decor should include calcareous, lime-based decor or filter media to keep those minerals high and pH, KH and GH buffered.
In the wild mbuna rarely top 7.5–10cm/3–4in total length but fed rich foods in the aquarium they can reach 12.5–15cm/5–6in. They are aggressive and territorial and you need to keep lots of them, so a large tank is a must.
To start right with mbuna a 120cm/4ft tank or larger is best. Yes, breeders and the shops keep them in much smaller set-ups but this ability comes with experience, and it’s far from ideal. Some species are classed more as dwarf mbuna, and these might do well in a tank of 90–100cm/36–40in, but even then a taller, wider tank with a volume upwards of 180 l/40 gal is best.
When creating a home for mbuna, try to replicate the lake environment — deep and wide. A 120 x 60 x 60cm/48 x 24 x 24in tank will be much more conducive to the lake effect than a 120 x 30 x 30cm/48 x 12 x 12in aquarium, which holds far less water and is much better suited to replicating a small, shallow stream.
Getting started with mbuna can be somewhat of a trap for the uninitiated, as many of the most widely available species are the least suitable for the novice.
Melanochromis auratus is probably the most widely available, with juveniles displaying attractive humbug patterning. It must be said that this is a very hardy, durable species — but it is also one of the most aggressive and will quickly dominate, then terrorise a new, sparsely populated tank. Males and females become duller and more dirtier-marked too, losing much of the bright striping.
A first foray into blue fish can also be folly, with Pseudotropheus socolofi being an attractive powder blue colour, but becoming aggressive and quite large with age, while Metriaclima lombardoi starts life with blue vertical banding on both sexes, the males developing a lovely bronzy yellow as they mature — along with a foul temper! Add a few unidentified hybrids and you can soon end up with an aggressive, nasty set-up, which is anything but relaxing to watch.
Seek out a cichlid specialist who will have more species and better labelling. There you will be able to buy bright yellow but mild-tempered Labidochromis caeruleus and dark blue but small in size and temper, Melanochromis cyaneorhabdos. You can also add a group of lilac-coloured Pseudotropheus acei — the least mbuna-like mbuna of all, being generally placid. Tropheops are underrated, subtly coloured and generally well behaved mbuna, which inhabit the shallows and graze algae. Some are quite collectable and any shop holding several species such as T. chilumba, macropthalmus, microstoma and sp. ‘red cheek’ are definitely worth their cichlid salt.
And if you want to break up the bright blues and yellows, how about a bit of brown? Look out for the subtle beauty of Pseudotropheus elongatus ‘chailosi’ or Cynotilapia sp. ‘Lion’.
Large aggressive species
These fish are best avoided by the novice mbuna keeper:
Smaller, less aggressive species
Try these instead:
Male and female mbuna don’t form mated pairs, and that does mean that male mbuna can be troublesome. To put it simply, every male mbuna wants nothing more than to be the only male haplochromine in the whole of Lake Malawi — or better still, the whole of the world.
Males want to adorn themselves in the brightest colours and live over the best real estate, and their idea of heaven is to be visited every ten minutes of every day by a female looking for a casual fling and who then disappears, never to be seen again!
Hell for a male mbuna is to be surrounded by other males — other better looking, more masculine males — who then eat their food, take up residence in their space and worst of all, take all their women. This results in a typical male response — fighting — and females who don’t know when to leave will get battered, too. If you’re 7.5cm/3in long and aquatic, never get within a few metres of a male mbuna with a rage on. It will hurt!
But of course the problem here is that most of our tanks are only a metre long — maybe a metre and half at best — so with what we now know about mbuna psychology, we can see that we have an anger management problem that needs to be addressed. Rival males and non-sexual females will always be in the vicinity of dominant, sexually charged males, so it’s how we deal with it which will make or break your mbuna “community”.
The first thing to consider is decor. In Malawi the rocks where mbuna are found would need moving with a JCB, but we can use lots of smaller rocks, say 15cm/6in across, in piles in the aquarium. A rock gives a male something to call his own, somewhere to feed and breed — and if you use limestone rock it will even buffer your water and help to make it hard.
Pile the rocks together and females, fry and subdominant males can take shelter in the crevices and get out of the line of sight of the aggressive male. He won’t attack them if he doesn’t know they are there.
Next, pile rocks high to further obscure the line of sight across the aquarium. Make a visual barrier and two males will separate and coexist, each defending his own tiny territory. Add lots and lots of rocks and you can keep even more males in this way.
The next line of defence is to overstock. You have lots of filtration and lots of aeration, so go wild (filter bacteria levels permitting), and quickly build up a high number of similarly sized, similarly aged (ideally young, sub 5cm/2in fish). Twenty individuals should be seen as an absolute minimum, but 30 or 40 is even better. Grow them up in a crowded situation where they all know one other and anger can be managed. Outnumber a male of each species by at least two females, so that one poor female doesn’t get singled out and harassed. Or don’t have any females at all — but you’ll miss out on the joys of breeding.
Like a cockerel with a group of hens, the one thing that’s really going to wind up your male is another male of his own size and kind. He’ll fight to the death to protect what is his, so a newly introduced, disorientated male will always come off worst. Passing on one’s bloodline overpowers every other emotion or driver in nature.
Overstock and the aggressive male can’t spend too long away from his rock chasing other fish, as another fish could take up residence while he is away (or so he thinks). And that’s how Malawi mbuna tanks work.
Feed with care
In nature, mbuna feed on aufwuchs (a German word, meaning surface growth). This growth on the rocks consists of short strands of algae, biofilms and the tiny critters living within it. At certain times of year mbuna will also graze on zooplankton blooms higher up in the water, and massive scale midge hatches which rise up hundreds of metres above the lake like huge plumes of smoke as they hatch and mate.
For the Malawi cichlid geeks it’s the subtle specialisation of the 1,000 species when times are tough and food lean, which is so fascinating. Like zebra and wildebeest on the savannah, which coexist by each eating different lengths of grasses, the mbuna do so by eating different lengths of aufwuchs, and grazing it in different ways. The underslung mouths of the Labeotropheus allow those fish to access and rip off the best algae growths in choppy water with very little levering, keeping their bodies flat against the rocks as they do so. But the more insectivorous Labidochromis have to turn their bodies head first, at 90° to a flat surface, and then expend more energy ripping at the algae.
So, in the lean times, each species uses its specialisation, be it for eating short algae, long algae, invertebrates, insect larvae, eggs, scales or even fry — that’s why there are so many different species in Lake Malawi rather than millions of individuals of just one or two species.
In the aquarium, these specialisations are virtually never called upon, so mbuna grow big and fat on rich diets and regular feeds. This gives rise to so-called “Malawi bloat”, although many other underlying factors probably also contribute to the disease. In a mbuna with bloat, the neck and stomach become swollen and firm to the touch; the eyes pop slightly. It’s almost always fatal.
Popular advice is to avoid rich foods aimed at South American carnivorous cichlids and instead offer mbuna specific diets, which contain lots of algae, vegetable matter, and low animal protein. Frozen bloodworm is also attributed to causing bloat, although it is actually very low in protein and instead high in chitin, and mostly water.
Leave off feeding for one day a week and your mbuna will take to the rocks, cleaning up algae and clearing out their systems.
8 essentials for success with mbuna
- Hard, alkaline water — pH upwards of 7.5; temperature 24–26°C/75–79°F.
- Well-filtered water — zero ammonia and nitrite; nitrate should be below 40ppm.
- Well-oxygenated water — add extra aeration with an airstone or Venturi.
- A large tank — 180 l/40 gal minimum, but ideally 240 l/53 gal or more.
- Lime based decor — to aid pH buffering.
- Rocks — provide lots of them to offer territories and hiding places.
- Overcrowding — 20-plus fish in every community.
- The right food — offer an algae-based diet aimed at herbivores.
Don’t let them hybridise!
Mbuna will hybridise in the aquarium, and for the sake of other mbuna buyers, this should not be encouraged. Don’t keep females without a male of their own species in the community and if fry are suspected to be of hybrid origin, don’t spread them in the hobby. Although exciting to some, a new species won’t be created in this way. Instead, that world record breaking cichlid diversity will be watered down and diminished — and those unique colours, patterns and specialisations will disappear.
Any tank you ever set up will be subject to an algae outbreak sometime. The trick is to learn to manage, rather than completely eradicate it.
WORDS: NATHAN HILL
Every newcomer to the hobby will be united in asking, somewhere around three or four weeks into their experience, about how to deal with the algae forming in their tanks.
It’s no coincidence that some tanks are hit harder with the green stuff than others. Algae are numerous in their forms, from microscopic green ‘orbs’ that drift like balloons, to long, pernicious strands of red or black that carry the resilience of a born survivor.
The basic algae problem involves a tank full of water, light (which supports plant life), nutrients (either too much or too little) and carbon dioxide (which may or may not be in your control.) Wherever these ingredients are found, they present an opportunity for algae to grow.
For the everyday aquarist, there are a few strains that might appear, and there are different ways to deal with each one. Algae is not algae, is not algae. There are the green
and red varieties, needing different handling approaches, plus the peril of ‘algae’ that isn’t even true algae.
It’s important to diagnose and understand what type you’re up against before you decide on what action to take against it.
This is quite a rarity in tanks (as opposed to ponds) unless you’re tampering with carbon dioxide and nutrient levels, but it can still strike out of the blue.
The cause is a unicellular alga that lives free in the water, too small to get trapped in filters, and too persistent to be diluted out with a simple water change or two.
Ammonia is implicated in causing and sustaining green water, and stirring up substrates, subsequently releasing ammonia in to the water, can be a trigger. Off the shelf algaecides may help, water changes do very little, and my own experiences have found that a temporary black out where lights are turned off and the tank shrouded to keep out any external light will help reduce it, but not always eradicate it.
To add to the frustration, it will often disappear in a day or two entirely on its own.
Green dust algae
An alga type that’s found mainly in new set-ups, green dust lives up to its name. It mainly forms on the glass and hard, smooth decoration like rounded stones, and
given time to cement itself in place it can be stubborn.
Attacking it frequently seems to make it linger, and aquascapers will sometimes just leave it alone for several weeks (until the glass becomes near impossible to see through) before removing en-masse by scraping it from the glass with a blade or plastic edged cleaner, and then syphoning out the removed algae from the base.
Oddly, in heavily planted tanks, a low level of nutrients can be part of the cause, but unless you’re a dedicated aquascaper you won’t want to add more plant food!
Blue green algae/cyano
If you suffer from this, then I feel for you. Blue green algae isn’t algae in the true sense, but is a type of bacteria that can photosynthesise. It will quickly drape all that it can in a tank with thin, expansive sheets that often peel away in large pieces. Controlling it is nightmarish, and short of using antibiotics (which are illegal without prescription in the UK) you’ve a long fight on your hands.
In a home tank, the cause is usually a combination of direct sunlight hitting the glass, combined with dirty substrates that harbour rich beds of organic matter. Ammonia can trigger it, and a new tank is likelier to get it than an old one.
To start controlling it, you need to physically remove as much as you can via net and syphon. At the same time, you need to work on substrates to get them scrupulously clean, as any muck down there will entice it to return.
To eradicate it, you’ll need a complete tank blackout for around four days, so turn off all lights and wrap the tank in something dark so that light can’t get in. It’s noted that increasing oxygen levels can also help out, so get an airstone in the tank too.
This is the most common alga you’ll meet, and it’s formed of tiny diatoms. If you’ve set up a new tank, it’s the first alga that will appear, and is associated almost entirely with the silicates and ammonia that goes hand in hand with an unestablished system.
Brown algae will vanish within a few weeks of setting up. If it doesn’t, that algae isn’t the problem, but rather something is stifling the maturing process of the tank. It may be an issue with the filter, or it may even be excess movement of the substrate. Stirring the base up too often can cause it to linger, but only when the tank is new.
Dealing with it is as easy as getting in the tank with an algae pad, wiping it from the glass or other hard surfaces, and then syphoning out what drops to the base of
Though some fish (like Otocinclus) will eat it, the paradox is that brown algae will almost always indicate a tank too immature to keep them. Clean and wait, and eventually the algae will go.
Green spot algae
Not to be confused with green dust algae, green spot is more tenacious and stubborn, with larger individual blobs.
In aquascapes, it tends to be associated with low CO2 and low nutrient levels, where in most domestic community tanks it tends to be a consequence of excessive lighting and poor water flow. Bright, near-static tanks are almost always problematic.
To clean from glass, hard scrubbing with a pad or magnetic cleaner will keep it in check, though a razor or plastic edge may be needed to remove it once it gets a foothold.
Green spot algae on decoration will require scrubbing with a toothbrush. Remove affected decor and brush it under running water.
Leaves showing coverage of spots are best removed using sharp scissors.
Performing a series of small water changes (10% daily for five days) may help to reduce some of the available nutrients. Cut back on the amount of light during the day — anything over eight hours is inviting green spot.
Black brush algae
‘Black’ algae is misleading, as this is actually classed as red algae. In the tank, it tends to be more of a sooty grey, but its presence is unmistakeable. Small, beardlike tufts of dark, fluffy algae will jut from all surfaces, ornaments and plants in a slow encroachment, until eventually the whole tank is smothered.
It’s associated with a few factors in community tanks. High phosphates are implicated, as is inadequate flow of water. Old light tubes in particular seem to promote its growth, and fluorescents over 12 months of age should be replaced to prevent it.
It can often be found living directly on wood, feeding on leeching organics.
Controlling it is nightmarish. Any plants that show signs of infestation should have the affected leaves sacrificed immediately. Any growths on glass should be scraped away with blades or plastic edges, and the tank syphoned to removed the fragments immediately after.
Decor that is smothered can be treated by removing it from the tank and soaking it for five minutes in a mixture of glutaraldehyde (such as Easycarbo, or Flourish excel) at a ratio of 25% treatment to 75% water. After soaking, rinse thoroughly before returning to the tank. Dosing Easycarbo to the tank will help to control brush algae in the long term, as it’s toxic to the algae but not to higher plants.
Water changes will help in some cases, while less water changing helps in others, as will certain fish and shrimps. Try redirecting filter outlets to provide more flow around the tank, or even consider an additional small pump or powerhead to increase movement.
Looking similar to black brush algae when small, staghorn forms long, antler-like tangles. It tends to prefer plants over substrates or decor, smothering leaves with its growth.
Dirty tanks with sediment trapped in the substrate are desired real estate for staghorn, and toss in slow water flow and ageing lights, and you’ve a perfect recipe for growth.
Cleaning the substrate, removing affected leaves, and treating with glutaraldehyde will all help, as will improved flow rates.
Fish and inverts: Some fish will consume algae as part of their natural diet. In fact, many species have long been marketed as remedies to outbreaks. Here are some of the classics...
Far from cheap, not always readily available and sometimes difficult to keep, aquarists just love those suckermouthed plecos. Here are some of the species that breeders and collectors adore.
WORDS: NATHAN HILL
1. Zebra plec
Scientific name: Hypancistrus zebra (High-pan-sis-truss zeb-ra).
Origin: Endemic to the Rio Xingu, Brazil.
Size: To 8cm/3.1in.
Tank size: Minimum 60 x 30cm/24 x 12in.
Water chemistry: Soft acidic to slightly base water; pH 6.0–7.5, hardness 2–16°H.
Feeding: Carnivorous fish that enjoys bloodworms, brine shrimp and even Daphnia.
Notes: Despite being threatened by dam construction, wild caught fish offered in the UK may well have been illegally caught and smuggled out via other countries. Tank bred/farmed fish are available and completely legal.
2. Gold nugget plec
Scientific name: Baryancistrus xanthellus (Barry-an-sis-truss zan-thel-us).
Origin: Rio Xingu and Iriri, Brazil.
Size: To 22cm/8.6in.
Tank size: Minimum 120 x 45cm/48 x 18in.
Water chemistry: Slightly acidic to slightly base; pH 6.4–7.6, hardness 2–14°H.
Feeding: Omnivore eating some algae and inverts. Offer Repashy gel foods.
Notes: Territorial with other cats, aggressive with other nuggets. Will leave plants alone in a planted layout.
3. Sunshine plec
Scientific name: Scobinancistrus aureatus (Scoh-bin-an-sis-truss or-ee-ate-us).
Origin: Rio Xingu, Brazil.
Size: To 30cm/12in.
Tank size: 180 x 60cm/60 x 24in.
Water chemistry: Soft acidic to neutral water; pH 5.8–7.2, hardness 2–14°H.
Feeding: Omnivore, offer prawns, mussels and fish pieces, as well as fruit and veg with the skin on.
Notes: Big and robust, and retains gorgeous markings into adulthood. Excellent in a tank with other large fish such as South American cichlids.
4. Blue phantom plec
Scientific name: Hemiancistrus sp. L128 (Hem-ee-an-sis-truss).
Origin: Rio Orinoco, Venezuela.
Size: To 18cm/7.1in.
Tank size: 120 x 30cm/48 x 12in.
Water chemistry: Soft acidic to neutral water; pH 6.0–7.0, hardness 2–12°H.
Feeding: Omnivore, offer tablets, gel foods, vegetables and frozen bloodworm.
Notes: Works surprisingly well in a peaceful, slightly acidic community tank, though can take a while to acclimate to a new set-up.
5. Royal plec
Scientific name: Panaque nigrolineatus (Pan-ak-ay nig-row-lin-ee-ah-tuss).
Origin: Colombia, Venezuela, South Central Amazon Basin.
Size: To 35cm/13.8in.
Tank size: 180 x 60cm/60 x 24in.
Water chemistry: Slightly acidic to slightly alkaline; pH 6.5–7.5, hardness 4–15°H.
Feeding: Veg, veg and more veg. Offer greens, peas, and fruit. Ensure there’s wood in the tank for them to graze on.
Notes: There are many varieties with subtle differences between them. Whichever one you get, expect someone to dispute its identity.
6. Flash plec
Scientific name: Panaqolus albivermis (Pan-ak-ay al-bee-verm-iss).
Origin: Rio Alejandro, Peru.
Tank size: 90 x 30cm/36 x 12in.
Water chemistry: Acidic to alkaline water; pH 6.6–8.4, hardness 4–18°H.
Feeding: Xylivore (wood eater), ensure wood is always present in tanks, along with offered vegetable fare.
Notes: Frequently misfed, these plecs go very well in a set-up with South American tetra, but they can become more territorial as they mature.
7. Colombian blue-eyed plec
Scientific name: Panaque cf. cochliodon (Pan-ak-ay cok-lee-oh-don).
Origin: Magdalena and Cauca basins, Colombia.
Tank size: 180 x 60cm/60 x 24in.
Water chemistry: Soft, acidic to neutral water; pH 6.0–7.4, 4–14°H.
Feeding: Xylivore (wood eater), ensure wood is always present in tanks, along with offered vegetable fare and occasional meaty treats like prawn.
Notes: Rarer than an uncooked steak, if you find one in the UK you’ll be one of a small handful
of people to ever see these fish in the flesh.
8. King tiger plec
Scientific name: Hypancistrus sp. L066 (High-pan-sis-truss).
Origin: Xingu, Brazil.
Tank size: 90 x 30cm/36 x 12in.
Water chemistry: Very soft acidic to neutral water; pH 5.8–6.9, hardness 2-8°H.
Feeding: Carnivorous, offer plenty of bloodworm and prawn, as well as carnivore tablets and pellets.
Notes: Prone to being confused with other species, you get a very pleasant fish for not too absurd a price. A real keeper.
9. Magnum plec
Scientific name: Baryancistrus chrysolomus (Barry-an-sis-truss cry-so-low-muss).
Origin: Rio Xingu, Brazil.
Tank size: 120 x 45cm/48 x 18in.
Water chemistry: Slightly acidic to slightly alkaline; pH 6.5–7.5, hardness 4–15°H.
Feeding: Omnivore, ensure algae growth but add veg like courgette and sweet potato.
Notes: Juveniles tend to be more contrasted than the adults.
If you’re tempted by killies but not sure which species to start with, you won’t go far wrong with Aphyosemion striatum, says Steve Davidson.
Common name: Red striped killifish, Striatum killifish
Scientific name: Aphyosemion striatum (Aff-e-o-see-me-on stry-ar-tum).
Lifespan: Around two years.
Ease of keeping: No problem for competent fishkeepers and a perfect introduction to killifish.
Feeding: Will accept some flake food, although as with all killifish they much prefer live foods. Frozen mini bloodworm is taken with relish.
Availability and cost: Sometimes found in shops, on internet auction sites, and certainly through members of the British Killifish Association. Price around £12–16 a pair in shops, but less if bought from a dedicated hobbyist/breeder.
Every so often we come across a fish that stops us in our tracks. Perhaps it’s the shape of the fins — or, as with the Striatum killifish, it’s the colour.
This stunning tooth-carp has colours that would rival the brightest marine fish, with shades of red, green, yellow and blue all packed into a slender body that is just 5–6cm/2–2.2in long. The colours are clearly defined, and similar to the vibrant punchy shades often found in a children’s playground. An added bonus with this little beauty is the ease with which it can be kept
Aphyosemion striatum is native to Africa, found in Gabon and Equatorial Guinea. It inhabits mainly small streams and swampy areas within or bordering the rainforest and has been found in water that is quite shallow. When collectors have been looking for small Aphyosemion species in the rainforest, many have reported finding fish close to the bank. Where trees overhang this creates some shade and here the water temperature will be slightly lower — often around 20–23°C/68–73°F. Aphyosemion striatum falls within this temperature range.
In the aquarium
This is the ideal species for the newcomer to killifish. It’s not too hard to obtain and is easy to feed as well as making a great breeding project — and then there’s all that colour!
You don’t need a large aquarium to keep these fish — a pair or a trio (one male, two females) can be housed in a 30 x 20 x 20cm/12 x 8 x 8in tank. Ensure you have a tight fitting lid as many killifish are aquatic gymnasts, and may launch themselves out of the water and through a tiny gap. The water needs to fill around 70% of the tank and be around 23°C/73°F in temperature — a couple of degrees either side of this can have an effect on spawning activity.
For many years I used mains water with the obligatory water treatment to render it safe for my fish, but a couple of years ago I switched to using 100% rainwater for my killifish and guppies. It has a pretty consistent pH of 7 but anywhere between the range of pH 6.6–7.2 should be fine for these fish. In the past it was common practice to use some pre-soaked Irish moss peat as a substrate for killifish, but if your water is pH 7 or below the peat could make your water too acid over time. Nowadays many killie keepers use pre-soaked coir as it is considered inert, so should not alter your water chemistry. An airline bubbling away quietly and a spawning mop or two made of a synthetic wool is all that is required. You don’t need real plants although they do enhance the appearance of the tank.
Some killifish species can be a bit reluctant when it comes to spawning, but A. striatum is a species that should present few (if any) problems for a reasonably competent aquarist.
Storing the eggs
The eggs of these fish are fairly small, but when the adults are conditioned well they will be laid in profusion. There is always some debate among killifish-keepers as to the best way to store eggs. Some people say to put them in a small container, such as a well cleaned 500g margarine tub containing some of the parents’ tank water. Others, like myself, favour putting them on a small amount of damp peat in a small container with a lid. I use small plastic containers around 45mm in diameter with a lid attached by a small integral strap. I cut up computer address labels for attaching to the egg containers. These can then be used to record the species name, date collected, and number of eggs.
The eggs take on average 16 days or so to hatch. I hatch eggs in small plastic containers made from a clear Tupperware type plastic, around 100 x 50 x 75mm (sold for craft purposes in stores such as The Range).
Rearing the fry
Fry are quite small on hatching and ideally should be fed newly hatched brine shrimp which is full of protein. A word of caution though, feed brine shrimp very sparingly. Any that is not eaten will die fairly quickly and foul the water. If this happens it’s very likely the fry will succumb to velvet. In my experience once this occurs with fry it’s fairly certain you will lose them, so exercise caution when feeding fry! Microworms that are kept in a Ready Brek type mixture can also be fed to the fry. A singular use of a child’s paintbrush is ideal for feeding these — just dip the brush into the worms so a few of them attach to the tip of the bristles and then swirl it in the tank.
With fry held in small containers you can monitor their progress. The relatively small amount of water will slowly evaporate within a fish room, so topping it up with similar water is required. I tend to decant off around 50% of the water into a cleaned out margarine tub, allowing me to see any small fry that have carried over. If you do not have the luxury of a space heated and dedicated fish room then you will need to find a way of keeping the fry container warm —floating it in the parents’ tank is an option, providing it won’t topple over.
Growth will be slow as is the case for most Aphyosemion species. As soon as they reach around 8mm long I transfer them to a small tank somewhere in the region of 20 x 10 x 10cm/8 x 4 x 4in. This gives them more room to develop. I still change around 40–50% of the water at least once a week to keep things sweet. Changing a portion of the water also helps to maintain an even growth rate among the fry. If you can arrange for a very slow trickle of air via an airline and valve/clamp then this will prevent the water from skinning over. If this is not feasible then gently moving the water around with a clean finger will do the trick.
When fry reach 12-15mm in length you can consider moving them on to something like a 30 x 20 x 20cm/12 x 8 x 8in tank. This is big enough for them to grow on but still small enough to be able to monitor the fry. You should be able to spot any uneaten food in a tank of this size and remove it before problems unfold. Continue with feeding freshly hatched brine shrimp which can be supplemented with some very small Grindal worms as the fry grow.
You can of course leave the eggs to hatch within the parents’ tank. The plus is that fry hatching in tanks alongside their parents seem to grow a bit faster than when hatching and rearing them separately. But some fish will devour their fry, and larger fry will sometimes consume newly hatched individuals, although just today I have found some fry a few weeks old swimming happily alongside their parents.
After a few months you should end up with some fish whose colours approach or even rival that of marine fish.
Join the club!
Become a member of the British Killifish Association. Find out more at www.bka.webeden.co.uk
Older aquariums can have issues of their own, leading to dead fish and terrible water. The tragedy is that it’s so simple to avoid this kind of problem, says Nathan Hill.
If you’ve kept fish for anything more than a couple of days, then you’ll be either directly or indirectly intimate with the problem of new tank syndrome, often abbreviated to NTS.
I won’t dwell. We should all know the basics of new tank syndrome, though discussion about the exact mechanisms is heated. Fish make waste, the filter struggles to cope with that waste, and contingency plans need to be in place. You might prefer ex-situ tank maturation or in-situ. These are arguments for another time.
Unfortunately for many fish, too many aquarists assume that new tank syndrome is the only water worry they’ll ever face. They imagine that this initial establishment period is the only time they’ll struggle with instability.
Because of this, they may be caught out by an equally dangerous, yet easily avoidable problem later down the line: old tank syndrome, or OTS.
In old tank syndrome, the definition of 'old' is open to some discussion. Tanks that have been running successfully for months or years may slowly turn bad, or they might suddenly crash altogether, with multiple casualties and a befuddled owner.
The problem all too frequently lingers unseen, and then manifests itself in a way that leads to conflict between fishkeeper and retailer.
Imagine the scene, if you will. A fishkeeper has a tank that they’ve kept successfully for two years. In that time, some fish have grown, while others — conceivably through old age — have died. The plants are large, maybe a little leggy, but still alive, and overall there is no reason to suspect any underlying malaise.
This fishkeeper opts to buy some more fish from a local store, deciding to pick up some delicate tetra types, given how 'mature' their tank is. A day or two after adding the fish, problems are noted. They look bedraggled, and show the first signs of whitespot. Not long after, the tank is knee deep in a full scale Ichthyopthirius pandemic, with old and new fish dying everywhere.
The immediate impression of the fishkeeper is that they have been sold diseased fish, and so they return to the store to confront the retailer and demand replacements — only to discover that every one of the original tetras still in store is the absolute picture of health.
As is their right, the retailer requests a sample of the fishkeeper’s aquarium water before a resolution can be made, and that sample, when it arrives, turns out to be diabolical beyond compare. So bad, in fact, that even without the new fish, the tank would have been weeks away from a wipeout anyway.
And that is how most people meet old tank syndrome.
More to water than filters
If I was going for an easy sale in a store, and I had to describe a filter’s function as simply as possible, then I might be inclined to say that 'it takes all the toxic waste and makes it safe for the fish to live with'. I suspect that for a lot of casual fishkeepers, that’s the impression they have in mind. Fish make waste, filter resolves waste, problem solved.
If only it was that that simple.
Filters only convert waste, and certainly not into something safe. Ammonia from fish is converted through nitrite and into nitrate. That much we all know, right? Water chemistry 101 right here.
Nitrate isn’t exactly a 'nice' chemical to have around. In humans, it’s implicated as a carcinogenic, while the lethal levels for different fish are slowly being understood.
As long as the filter is working, and as long as the fish are producing waste, then there will be nitrate produced.
It would be wrong to say that some fish develop a tolerance for nitrate, because that implies that they can be unharmed by it. Rather, I consider long-term nitrate exposure in fish as analogous to alcoholism in humans. It slowly affects organs, reduces lifespans, and plays havoc with immune systems. To be in optimal health, they need to live lives devoid of it. Like drink in humans, a little bit of it might not be a major problem. A lot of it is.
The problem is that aside some slight loss of condition, maybe dull colours or lethargic behaviour, there’s little to see that suggests a fish is suffering in high nitrate levels.
Even worse, if a fish is then taken from water where there is very little nitrate (such as in the case of my hypothetical retailer earlier) and suddenly exposed to high nitrate, then it is likely to shock it. To stay with the drinking analogy, someone unhealthy but used to drinking heavily would cope better with a ten pint boozing session than a person in perfect health who has been a lifelong teetotaller. Think Rab C. Nesbitt versus a nun. It’s a crude way to explain it, but that’s pretty much what happens.
There’s also phosphate to consider. Phosphate is introduced courtesy of the foods we offer our fish. It is not metabolised to any degree, and ends up excreted as waste.
Phosphate has questionable health impacts on fish, and is much better understood to inhibit invertebrates. Marine keepers in particular struggle to control it. As phosphate builds, the most obvious symptom is increased algae growth. In waterways, excess phosphate leads to eutrophication (it is the prime cause of eutrophication), which turns rivers and lakes bright green with algae, stripping the water of oxygen and killing the inhabitants. Such pandemics are not well known in aquaria, though that’s not to say they never happen.
Again, all of this is very easy to avoid.
The acid effect
The worst culprits for OTS are tanks that become victims of their own success.
An underlying problem involves the hardness — the mineral content — of the water. Carbonates play a vital role in buffering aquarium pH, as well as providing a source of carbon for some plants and bacteria: specifically those bacteria helping to convert fish waste.
When carbonates become depleted, two problems follow. Firstly, the osmoregulation of many fish (the way in which they regulate their minerals in the body) is compromised, sometimes to lethal extents. Secondly, without the buffering effect of minerals to keep it in place, pH in the tank can drop or swing wildly, leading to acute acidosis. Either of these can kill a fish outright, and both will cause acute and chronic stress.
Bacterial action inside the filter further alters pH. Biological bacteria, as they work, produce quantities of hydrogen ions. In water, these take the form of hydronium, and the amount of hydronium relative to the amount of hydroxide dictates how acidic the tank is. The more hydronium, the lower the pH, and with a busy filter churning the stuff out, pH levels can soon plummet. Combine that with the simultaneous removal of buffering carbonates as already mentioned, and you have a pH disaster in the waiting.
To make things even worse, if the pH does drop too far then it will stop the filter from working properly. In acidic conditions, the bacteria that convert ammonia struggle to function, and below 6.0pH they might stop working altogether.
Prevention trumps cure
Every parameter mentioned here can be tested, inexpensively and easily. Liquid kits, dip strips, monitoring devices — there is no excuse. Folks who say they can visually assess their tanks are deluding themselves, at the peril of their fish. You cannot ‘see’ the nitrate content of a tank any more than I can 'see' the alcohol content of a glass of gin.
Over the years, there has been something of a misunderstanding. Many aquarists are only keen to test — or in some cases have their retailer test for them — while they are cycling the filter at the start of the tank’s life, and wrongly assume that once that’s out of the way it’s plain sailing.
Testing for the chemicals associated with old tanks needs to be performed weekly, or fortnightly at least. Nitrate, GH, KH, phosphate and pH are all reliable indicators for the health of your tank. At an absolute minimum, nitrate and pH need to be closely watched.
Start by testing your water supply, whether you use tapwater or RO mixes purchased from a store. Unless you are deliberately altering the water in the tank with acidic products like Catappa leaves, then a difference of 0.5pH between the aquarium and the water source is a huge cause for concern. Nitrate levels always need to be low, but if the tank water tests at 40ppm greater than the water source, alarm bells should be ringing.
If you test for phosphate, then levels in the tank should be no higher than 0.5ppm greater than those in the water source. At 5ppm or more, action is essential.
GH and KH levels in the tank should be no more than a couple of degrees lower than source, though it’s likely that KH will deplete faster out of the two. Unless you’re keeping incredibly softwater fish, a tank reading below 5°KH is a warning that cannot be ignored.
Testing is one thing, but the actual process of prevention counts for even more.
The way these issues are avoided is simple: water changes, gravel cleaning and maintenance. There’s no short cut here, and no way to avoid the inevitable. Old tank syndrome is caused by a lack of tank care, plain and simple.
Water changes will fix most things. Taking old water out and replacing it with fresh will dilute down the levels of nitrates and phosphates. Because the newer water will be richer in minerals, it will also help to boost hardness, increasing the GH and KH, and stabilising pH.
If the tank is in a bad way, then opt for a course of small changes — one won’t be enough. Changing 25% daily or every other day will slowly bring things back to where they need to be.
If things really are extreme, to the point of a tank crash, you may want to perform a larger change of 50–75%, though this is a drastic measure. Adding a mineral product such Tropic Marin Remineral Tropic will help instantly boost the GH and KH. An excess of ammonia in the water may be treated with the likes of API Ammo Lock. Nitrates and phosphates can be reduced by using dedicated resin media placed into the filter.
Essentially, all of these points need to be tackled at once. Addressing nitrate levels while the pH plummets is like washing a car while the engine is on fire.
Cleaning gravel is paramount to avoiding OTS. All of the 'hidden' waste down amongst the substrate will gobble up carbonates, and churn out more nitrates than a rotting tree. Left too long, aquarists can even face the rare but lethal hazard of hydrogen sulphide production, where oxygen levels in the gravel drop so low that the 'wrong' kinds of bacteria can proliferate.
A simple gravel syphon will keep on top of this collected slurry. Using a cleaner like the Fluval AquaVac+ will pull up much of it, though it’s just as easy to combine gravel cleaning with a water change and kill two birds with the same stone.
Maintenance is essential, especially for the filter and any plants. Filters accumulate waste much like the gravel does, while some media which removes the likes of nitrates can become exhausted and release much of what it has trapped back into the tank. Frequent changing of resin media, and regular cleaning of sponges is vital.
Plants can also contribute to OTS if kept poorly. Old leaves may drop or degrade, and then they’ll start to rot — meaning more carbonate depletion and more nitrates!
By combining regular water testing with regular water changes and maintenance, there’s no reason for anyone to suffer from old tank syndrome.
You never know, those basic chores might even save you from having an embarrassing fracas with your retailer one day over dead fish..
Potential causes of OTS
- Inadequate water changes.
- Overstocked fish levels.
- Dirty gravel.
- Uneaten food.
- Unwashed filters.
- Dead fish/shrimps/snails.
- Decaying plant matter.
- Low GH or KH water supply.
- High nitrate water supply.
One of the UK's best known discus breeding and showing celebrities shares some of his secrets to success. Nathan Hill meets 'Chen' of Chen's Discus.
"I’m fish rich," says the man offering me tea in his kitchen. He apologises that it’s not too good — he never makes the stuff for himself. But frankly, I’m too preoccupied with the amazing fish next door to notice.
As a journo doing the rounds, one name gets dropped around me more than any others in conversations — Chen. Chen’s fish have a reputation of being some of the hardiest and most vibrant selectively bred fish the UK trade has to offer, and I’d be hard pushed to disagree. The lines of tanks that dominate his two fish houses are bursting with all the colours of a dissected rainbow, while curious but sanguine faces press against the glass like greedy carp. His fish are as fearless as they are dazzling.
As a hobbyist myself, and one who has lived through the near-religious fervour of Chen-worship and mystery, I was taken by a stark revelation about the man behind the legend. He’s not called Chen. Francis Hu, Chen’s founder and owner isn’t even entirely sure himself how the name stuck — it was originally his mother’s surname, but beyond that it’s hazy.
Despite becoming an aquatic legend, he’s as human as I’d hoped. A hobbyist above all else, with a long history of fishkeeping, he’s been around fish his entire life, with a tank of his own guppies by the age of five; he was a precocious fishkeeper.
"Guppies used to be strong," he tells me. "But now wild discus are hardier than they are." I’d ask him to back up his claim, but he already has by showing me his pristine wild discus happily foraging and spawning.
In 1994, he started keeping discus for the first time. He had an uncle who’d bred some that same year, and Francis became transfixed by them. He’d venture out with his brother, and they’d be rapping at their local shop’s door at 6am awaiting the new fish, which they’d select straight from the bags and race home with.
He had to hide them from his mother who was against them buying fish, and had them stashed in a side room. One day their plan was rumbled, but quick thinking got them off the hook. "We convinced her that we bred them," he says with a laugh. That simple lie was a premonition of what would follow.
What started low key as a hobby grew and grew. He insists his interest is breeding and keeping, and downplays any commercial side of his operation. His thing is fish first, business second.
His main role is as a college lecturer, in a part time and consultancy role. He was full time but cut back to just two days a week to give himself ample fish-house time.
"It was back in 2002 or 2003, I just had a night-time epiphany,” he says, "and I thought why aren’t I doing discus as a business?
"I had some good Malaysian contacts and started importing them. Then friends began asking me about them, and buying them from me. It grew from there."
A cursory count up of his facilities now puts him at over 80 tanks, from 45cm/18in cubes, up to 150cm/ 60in lumps, spread out on a variety of racks — and a pond.
A pond for discus
The pond is the most curious thing I’ve seen. With a 500 l/110 gal capacity, and fed by his home-made trickle filter filled with K1 media and foams above, the thing is packed with the compressed, flattened bodies of the fish, yet Francis can tell each and every one apart. I try to round up a number, but there are simply too many.
This was originally built for stingrays, but is now a gigantic (if well stocked) rearing pond for his show fish. To give a little perspective, this one collection alone consumes around 1kg of beefheart mix every single day.
Using a long net, Francis deftly hooks out previous winners and up-and-comers, showing me the subtle differences between them.
"Females lack the show-quality blue vibrance," he says, pulling out fish after fish to make his point. "For blues, the males make much better show fish. For red, you want the females."
Pressed on it, he tells me about the beefheart that he feeds profusely to his fish. "I get through at least four or five kilos every day," he says. "It’s not just beefheart though; there’s mussel, spinach, spirulina, flake, prawn — all sorts in there. It’s what I feed exclusively. It’s actually made by Ditone Discus, which I sell," he adds with a grin. "I must sell a good 100–150kg a month right now…
"Discus need big and meaty foods. Giving them anything else is like us trying to live on baby food. And I don’t use bloodworm. That’s bad for discus as it carries pathogens."
Francis puts food down as the second of his ‘big three’ to discus success. "You need good fish to start with," he says, "and then you need to feed them good food. After that you need good water, by which I mean fresh and clean. Don’t get bogged down by obsessing over parameters."
Making a champion
"Traditionally the UK has been seen as bad for discus," Francis says. "But as of a few years ago, we’ve started cleaning up the international contests."
He’s definitely helping to change the UK perception. Last year he journeyed to a Spanish contest and picked up over ten awards for his fish. He turned up with so many different coloured fish they started calling him ‘Rainbowman’. The year before he only took three fish — and took first, second and third place respectively with them.
Planning in advance is essential, and Francis has his ideas set up to three years before a show. "It takes 16 to 18 months to get a show fish to grow to a good size," he says.
Next year he expects some 20 or 30 fish to come out of his pond in show condition, and they’ll be travelling all over; he has contests lined up in Singapore, Spain, Italy, Holland, France as well as here in the UK. With such a predicted winning streak, it’s not surprising that others want to affiliate with him, and Chen even has an alliance with a member of Qatar’s royal family, representing a prince in European contests.
So how does he do it?
Francis secures his bloodlines from Malaysian breeders, when not rearing his own fish. In 2007 he flew out to see them after some issues of consistency — what they thought he wanted wasn’t exactly the case. They listened to what he had to say, and he showed them how he liked fish to be fed, handled, packaged and kept. He instigated protocols and initiated record keeping in every sphere.
"We’ve got a good rapport now," he says, "and I can ask for fish and they immediately know what I’d like. They steer me away from anything I wouldn’t like. Since I went over, I must have had at least 70 shipments from them."
Key to his success is refusing poor quality fish. Francis has a very clear vision in mind of how a fish should look, but he also knows that if he accepts any chaff then he’s setting up a bad precedent for the future.
"Buy a bad fish and you’ll be trying all the time to recover it," he says. "Lots of people make this mistake, then after a while they give up because of their bad fish, and perpetuate the myth that discus are hard to keep.”
"My first priority is for shape. Discus should be a perfect round shape, or as near as possible to that. Spherical is good. If it’s not shaped like a disc, then don’t call it a discus.
"My second priority is colour and markings. They need to be uniform and intense to win me over.
"The third priority is for eye colour. I prefer fish to have an intense red eye, though not all strains have this."
This order of ranking varies from nation to nation, it seems, with European breeders placing more emphasis on pattern and eye colour first, then breeding those fish to the shape they require.
"There’s an expectation of good fish that differs between keepers, too. Some like colours, while others are interested in good shape."
Francis has simple advice for those wanting to grow their fish on to show standards. "Water changes,” he says, “are essential for good growth. I aim for at least 50% every other day, and my pond gets a 90% water change daily.
"Water changes are directly proportionate to good growth and good health, and they’ll fix many major ailments like fish not feeding."
So simple it’s perfect
Despite many people claiming discus to be delicate, demanding fish, Francis uses the barest of essentials to keep his in pristine shape.
Throughout his multiple racks of tanks, the filtration theme becomes obvious as a simple staple — sponges, wool and some K1 media floating about in trickle towers. That’s as advanced as it gets.
For those imagining his water bill to be skyrocketed by the vast wastage of a heavy-duty RO unit, you’re also mistaken. Everything here is kept in ordinary, everyday Harrow tapwater.
"A lot of Malay breeders are Buddhist," Francis says, "which means they won’t cull any of their fish; they’re pacifists to the extreme. Instead they release their inferior fish into lakes. The thing is, there are people the other side of these lakes then catching them out for the hobby.
"The interesting thing in Malaysia is that only B-grade discus are on sale. All the A-grade stuff is exported."
With as many fish as there are at Chen’s, hygiene is essential. "There’s a disease out there simply called 'discus plague'," he tells me, "and nobody’s really certain about the diagnosis. But if you get it you’ll have 90 or 100% mortalities. Some keepers testify that it can travel about in the air, but I’m not so sure. Early signs are clamping of fins, darkening of the body, lethargy, refusal to feed, that kind of thing. By day four of infection they’ll be huddled in the corner. It seems to be a mixture of protozoan and bacterial infections.
"I sterilise my hands even after a handshake now, it’s just too high a risk not to. It only needs a drop of water, and that can be carried on a plant, or net, or whatever."
It’s the fear of this illness that has Francis putting all fish through a mandatory one-month quarantine. "If it meets a naïve fish, it’ll go down with it fast. I keep everything under a one-month observation, especially if fish have been exposed to cold in transit. They need time to get fed up and used to the UK water."
He’s wary of another discus killer, too. "It’s usually misdiagnosed as discus plague — the difference is that plague makes your water smell. But velvet disease is nowhere near as bad, with only 20% mortalities or so.
"Internal flagellates need to be watched out for. Fish will stop eating, and become shy. Then they’ll have fluffy white faeces.
"It’s when the immune system stops that the worms cut in — often if the fish haven’t been feeding for a while. But it can also be bad water, bad food, or just an underlying problem in the fish. This is why you shouldn’t buy bad fish.
"Kusuri discus wormer will cure it, but metronidazole is better. You’ll need a vet to get that though. And you’ll still lose quality and not recover all the fish. It’s very reliant on the keeper, and people with good husbandry don’t get it.
"There’s a big difference between worms and flagellates. If faeces are white and segmented, you have worms, and you’ll need praziquantel. If faeces are fluffy and the fish aren’t feeding, you’ve got the flagellates."
I ask if his customers ever have fish issues. "Not from bad fish," he says, "but from mishaps. I help out where I can though. As I said before, I’m not exactly fish poor.
"Sometimes I’ll raffle off fish for charity. We had one a little while back that raised £600 for cancer research. Others got on side, like CE essentials and Ditone food, and Devotedly Discus. We’re a good community, and I can afford to give the occasional fish away.
"But it is an expensive hobby," he adds."I’ve got a lot of personal fish, and they’re not cheap to maintain."
Taking a last look around, I’m inclined to agree. Francis may have poured a lot of money in to his passion over the years, but on the back of it, he’s not fish poor at all. In fact, a lot of folks would consider him one of the richest men alive…
Chen’s prices start at around £10 for a 2.5in hobbyist’s fish, while average 5-6.5in adults command between £75 and £100 each. For show fish or competition calibre fish, prices can sit anywhere between £180 to £900. During my visit, one intense yellow discus priced at £700 awaited collection that day.
For more details,
His fish are available for both retailers and hobbyists.
Why not take out a subscription to Practical Fishkeeping magazine? See
Don't forget PFK is also available in digital format.
for more information on the iPad or iPhone version.
for details of the Android version.
The International Aquatic Plants Layout Contest saw a record number of entries this year. Here are some of the aquascapes that made it into the top 20 along with the judges' comments. Check out the February 2015 issue of PFK for this year's Top 7.
Truong Thinh Ngo, Vietnam
Title: Nature’s Melody (pictured above)
Aquarium: 120 × 45 × 40cm/48 x 18 x 16in.
Comments: This layout features the bold use of large, thick driftwood. A dynamic aquascape is successfully achieved by bringing out the best of the driftwood. Its arrangement of aquatic
plants mainly using epiphytic and tape-like species produces a natural feel. Large angelfish make this aquascape more powerful and impressive.
Nichole Wong, Hong Kong
Aquarium: 120 × 45 × 45cm/48 x 18 x 18in.
Comments: Unique stones are used as a layout material. A good balance in the size and arrangement of stones leads to a great presence of the composition. The cosmetic sand from the foreground towards the inner side of the centre adds a bright touch and
depth to the layout and further emphasises the stone composition. Aquatic plants used match the texture of the stones.
Chao Wang, China
Title: Kingdom of Spirits.
Aquarium: 150 × 55 × 45cm/60 x 22 x 18in.
Comments: Thin trees stretching the length and breadth of this layout are reminiscent of ivy and aerial roots hanging in jungle. The trees are entwined so that not even a hand can get through, giving an impression sight of untouched nature in a lush jungle. Two lines of cosmetic sands followed by an open space add a bright touch.
Masashi Ono, Japan
Title: Beautiful autumn.
Aquarium: 114 × 52 × 52cm/46 x 21 x 21in.
Comments: The use of different colours of aquatic plants is impressive. The contrast of bright red stem plants and dark green mosses is very beautiful. The composition surrounded by stones produces a unique visual effect and the shade of stone firms up the impression of the aquascape. Sawbwa resplendens add grace to the aquascape.
Serkan Cetinkol, Turkey
Title: Meet up the winds.
Aquarium: 120 x 45 × 45cm/48 x 18 x 18in
Comments: This layout depicts a realistic landscape of a lake surrounded by forest and sheer rock mountains. Perspective is emphasised by the contrast of the large tree in the left front and the forest at the back, creating the illusion of a natural landscape. It feels undeniably odd to see fish present in such a terrestrial landscape.
Katsuki Tanaka, Japan
Title: Great waves of wilderness.
Aquarium: 120 × 45 × 45cm/48 x 18 x 18in.
Comments: The repeated use of driftwood in the same pattern is impressive. Perspective is emphasised by the contrast of large driftwood in the front at both ends and very small pieces at the back in the centre. Mosses attached to the driftwood create a unique atmosphere reminiscent of dense wood.
Hironori Handa, Japan
Title: The world behind peacefulness.
Aquarium: 120 × 45 × 45cm/48 x 18 x 18in.
Comments: An aquascape is expressed using driftwood and stem plants. This layout uses a classic concave composition, but a depth is naturally created towards the open space by the driftwood arch in the centre. Aquatic plants are n a good balance and the fish match the aquascape well.
Julien Voultoury, France
Title: Hades’ breath.
Aquarium: 120 × 40 x 50cm/48 x 16 x 20in.
Comments: The combination of stones and driftwood gives a wild impression. The layout is broadly divided into three parts, and perspective is expressed by making the centre a near view while the both right and left sides create a distant view. The use of mainly epiphytic plants such as mosses and ferns emphasises the wild feel of this layout.
Robertus Hartono, Singapore
Aquarium: 90 × 45 × 40cm/36 x 18 x 16in.
Comments: Perspective is skillfully expressed by a bold arrangement of driftwood and winding flow of cosmetic sand. The planting and the combination of stones and driftwood are very natural. The fish also match the atmosphere well. However, the aquascape would have looked more natural without the waterfall.
Olivier Thebaud, France
Aquarium: 120 × 60 × 60cm/48 x 24 x 24in.
Comments: The composition, made of a bold arrangement of large driftwood, is powerful and effectively expresses the perspective. Splendid balance of colour is achieved with reddish wood, white cosmetic sand and green aquatic plants. The use of roundish stones skillfully expresses a river bottom.
Jiraporn Sripraserth, Thailand
Title: Medicine cabinet.
Aquarium: 180 x 60 × 50cm/72 x 24 x 20in.
Comments: This layout is reminiscent of scenery of Guilin, China. A landscape of many odd-shaped rocks is depicted by standing stones in a panoramic aquarium. Expressions of landscape and aquascape are perfectly blended.
Jian Feng Zhang, Macau
Title: Great momentum.
Aquarium: 120 × 50 × 50cm/48 x 20 x 20cm.
Comments: This layout uses stones featuring characteristic red and white stripes. A terrestrial landscape is skillfully expressed by the arrangement of different sizes of stones to emphasise perspective. With the effectively planted mosses, the exposed stone surface looks exactly like a real cliff.
Atsushi Suzuki, Japan
Title: Delightful green.
Aquarium: 124 × 48 × 56cm/50 x 19 x 22in.
Comments: Skillfully depicts a natural feel using stones and driftwood. The shadow below the stones and the driftwood entwined around the stone add a natural depth. Well-balanced composition, effectively-made open space and cosmetic sand create perspective and flow of water.
Tristan Lougher explains why it pays to be prepared before stocking the tricky Powder blue surgeonfish.
Common name: Powder blue tang (surgeonfish).
Scientific name: Acanthurus leucosternon (Ack-ann-thur-uss loo-co-stern-on).
Size: To 23cm/9in.
Origin/natural habitat: Reef flats of the Indian Ocean from the east coast of Africa to Indonesia. Reported also from Bali in the Western Pacific.
Tank size: 400 l/88 gal plus.
Water chemistry: Ammonia and nitrite should be zero. Stable pH 8.1-8.4 is advised. Nitrate should be below 25ppm, ideally lower.
Approximate lifespan: Five years plus. Specimens kept well should live into double figures.
Sexing: External sexual differences have been reported such as nuances in body shape and pattern, but these are not discernible in any but the largest most mature fish where females are substantially larger than males.
Spontaneous purchases of marine fish can work but often don’t. There are so many species to choose from already, and there are several new-to-the-hobby species being imported every year. So, it’s perhaps unsurprising that aquarists can encounter fish they have never seen before in their dealer’s aquaria.
However, there are many fish that are instantly recognisable and about which there is an abundance of information.
Popular because of their ravishing good looks, affordability and widespread availability, one might be forgiven for thinking that they are easy to keep too. While by no means impossible, they can present unprepared aquarists with serious problems. However, a little background research and planning means that an aquarium can be established that provides for the specific needs of these fish in the long-term.
The Powder blue surgeonfish is many things: iconic, beautiful and yet potentially frustrating when it proves difficult to keep. Establishing an aquarium that addresses its particular needs and potential problems from the moment of its conception through to design, construction, then finally stocking is a way of avoiding many of the potential problems with this beautiful surgeonfish. Of course, most Powder blues do not have their entire system designed around them and they can still thrive in mixed systems. However, many aquarists have learned the hard way not to impulse buy one. Most of the key points that help aquarists to achieve success with this species are applicable to any aquarium, but for those wanting to recreate a little slice of nature, the reef flat aquarium is a great place to start.
In common with many surgeonfish, the Powder blue surgeonfish will fiercely defend areas of macroalgae from competitors or indeed any fish it perceives as a threat. In its natural environment, it may have to see off marauding shoals of the rival surgeonfish such as the Convict surgeon, Acanthurus triostegus, with aggressive attacking use of the scalpel-like scales located on its caudal peduncle. Although large shoals numbering hundreds of Powder blue individuals are also seen with regularity, it is generally intolerant of members of its own species and, at the margins of their territories, pairs will display and skirmish with rivals.
Its laterally compressed body shape and low-slung mouth are ideal for getting into nooks and crannies to remove algae, and it will busily swim throughout its territory searching for food. Here it might form loose associations with other species of surgeonfish including members of the genus Ctenochaetus, the bristletooth tangs. It has been suggested that this form of tolerance of similar species is convenient to each, as it increases the chances of new browsing sites being found and also offers some safety in numbers from predators.
Stop problems before they start
Researching potential issues with fish before establishing an aquarium for them allows the aquarist to manage problems before they occur. Aquarists that aspire to maintain the powder blue in the short, medium and long-term must address and solve each of these problems through system design and careful selection.
1. Their tendency to invite disease when stocked into their new home. They invariably contract Cryptocaryon (marine white spot) between two and ten days after being introduced.
2. Specimen selection: Is it feeding? Is it healthy? Of course, these types of questions can and should be asked of any fish before purchase, but for some marine species, identifying those individuals that are bold and greedy in their feeding behaviour can make their transition to the home aquarium an even smoother one.
3. Their territorial nature: many marine fish are territorially aggressive and the Powder blue isn’t the worst of them. It isn’t even the worst surgeonfish, but the same instincts that drive it to defend it’s patch of alga from raiders can kick in in the home aquarium, and in a closed system this can lead to serious injuries being sustained by its tank mates.
Buy better fish
Although research and planning are essential when selecting fish species for inclusion in a saltwater aquarium, it is vitally important that decisions concerning the actual specimen to be stocked into your aquarium are based on the individual rather than the species. Hopefully, you will already have determined whether the species itself is suitable for your particular aquarium, and that includes both hardware and species stocked/to be stocked.
Try to see a number of Powder blue specimens before you buy one. How do they compare with specimens you saw during your research? How do they compare with wild photographed fish? This should help give you a feel for the species, how it looks in a dealer’s aquarium and some understanding of what to look out for in the individual you end up buying. It is also useful to decide whether a smaller or larger individual is better stocked in your particular circumstance, and that might be influenced by the size and disposition of the other fish to be stocked.
When it comes to the time to buy, ensure that you see it feeding before you commit to the purchase. Ideally, it should browse on algae (dried and/or natural forms) in addition to meaty offerings such as Brine shrimp or Mysis.
Avoid individuals where the spine is visible; it’s possible to reverse the weight loss incurred when fish are collected and shipped and this is likely to occur when fish are fed sufficiently well on quality foodstuffs. However, this is a variable that the new Powder blue owner doesn’t need, and having high standards during the selection process should increase the chances of success.
Occasionally, specimens that are feeding well on flake and pellet diets can be found, and those are likely to be the best settled. Ask how long an individual has been in residence at the dealer’s; the better individuals are likely to have been in stock for a number of days or weeks.
How do we define 'better'? It’s not all about colour although that too can be an indication of health and vitality. Sometimes fish held in intensive marine fish-only systems can lose a little colour over time. The good news is that if the aquarist prioritises the fact that they are feeding well and have recovered from shipping over vibrancy of colour then the intensity and beauty of their colours should be regained within a matter of days in most instances.
Add tank mates first
The benefit of the creation of an aquarium that provides for the needs of fish that can be classed as 'tricky', is that more straightforward species will usually benefit from the extra planning and enhancements to the system. For example, surgeonfish are not the only species to suffer from white spot infections and therefore inclusion of a UV benefits all newly introduced fish. Establishing the aquarium to be sympathetic to the fish’s natural environment could even inspire the aquarist to pursue the biotope aquarium where the sunlit reef flat fauna is recreated to an extent.
The good news is that the Powder blue will live with almost any tank mates given sufficient time to settle in a new home, but its territoriality can be an issue. The willingness to form schools with other, similar algae-grazing species in the wild is not something to be attempted lightly in the aquarium. Indeed, it can be best avoided altogether. Their intolerance of competitors for algae might be understandable, but less easily explained is their apparent hatred of butterflyfish. None of these blends of fish groups are impossible to recreate in the home aquarium but perhaps best avoided in a system where the well-being of the Powder blue is a priority.
Bear in mind that the territorial nature of this surgeonfish is likely to be enhanced by the aquarist offering meagre rations; an approach often adopted by aquarists who understandably want to prioritise their water quality. One of the best ways to avoid conflict is to make this the final large-fish addition to the aquarium, i.e. after all of the other species have been given a chance to settle over a number of weeks. This might not eliminate territoriality entirely, but it should reduce it. That, together with some suitable choices for tank mates can make all the difference.
Another possible solution to the stocking of territorial species is to stock all potentially aggressive species simultaneously and as small juveniles. In the case of most surgeonfish and tangs, which may compete for natural algae resources in the aquarium, there may be limits regarding just how small the specimens available to be stocked are. At least adding them at the same time means that they are all in the position of having been stressed while being moved to their new aquarium and will settle in at similar rates.
This is particularly useful when stocking surgeonfish that are even more territorially aggressive than the Powder blue: surgeonfish such as the Red Sea’s Sohal, Acanthurus sohal, and the Indo-Pacific’s Clown, A. lineatus.
Smaller, busy fish such as anthias (Pseudanthias spp.), damselfish (Pomacentridae), dottybacks (Pseudochromis spp.), fairy wrasse (Cirrhilabrus spp.), peacock wrasse (Macropharyngodon spp.) and flasher wrasse (Paracheilinus spp.) are all suitable groups with which Powder blues will mix with the minimum of conflict. Stock larger fish such as dwarf angelfish, larger wrasse and angelfish before the Powder blue. Of course, any species choices will also be influenced by the variety of sessile invertebrates, if any, that are also stocked.
For the majority of specimens, once the first month in their new home has been successfully negotiated, they will go from strength to strength. However, water quality must be maintained to high standards and care must be given to the diet of the surgeonfish. Given that the Powder blue is one of the last fish stocked into the system, at least the last fish of any size that should be stocked, attention will have to be given to feeding all of the other fish in the aquarium too and to ensure that they are not competing too strongly with
the Powder blue.
One of the best ways to offer food to this fish is using nori or other forms of dried alga (dried sushi nori is the form I find most Powder blues accept most readily) on a seaweed clip daily. This should ideally be placed into the aquarium in the morning (or when the daylight period of the aquarium begins), so the fish can browse throughout the day. Meatier offerings can be made; pellets and flake are often accepted by this species, as are familiar frozen diets such as
Mysis and Brine shrimp. There are many other formulations of frozen food containing algal enrichments or high percentages of vegetable material that are also suitable. Keep the diet varied and of high quality, but always offer the dried alga.
How to set up a Powder blue surgeonfish tank
Tank size: 400 l/88 gal is an absolute minimum for this species long-term. It will afford swimming space for this active fish and a water volume that is sufficiently large to afford some stability to the system.
Filtration: For me, the best way to create an aquarium sympathetic to the needs of a Powder blue is to make it a living rock based system. This means the bacteria within the rock itself will provide the biological filtration: the removal of ammonia and nitrite.
Nitrate can be controlled to an extent by other varieties of live rock based bacteria and enhanced through the use of carbon dosing, whether with liquid alcohol based products or through the use of bio-pellet reactors. A good-sized, efficient protein skimmer is essential whether carbon dosing is employed or not.
Water currents and their intensity will be determined by the species of coral where stocked, but Powder blues do seem to enjoy areas of vigorous water movement provided by stream-type pumps, as long as they have areas where they can find quieter water.
Equipment: You are going to need an ultraviolet (UV) steriliser. You might be one of the lucky people who stock a Powder blue that never develops a protozoan parasite such as white spot (Cryptocaryon) or marine velvet (Amyloodinium), but that would place you in the minority of aquarists with experience of this species.
Thinking you might get lucky is a big mistake, and why endanger the life of not only your Powder blue, but also the rest of your stock, as the aforementioned parasites are highly contagious and potentially lethal. This, coupled with the fact that treatment options in a reef aquarium containing live rock and corals are extremely limited and it becomes clear that the UV cannot be seen as an option; it’s compulsory. Prevention is always better than cure in these situations, and running the UV when the fish is introduced to the system and for a period of three to four weeks subsequently will increase your chances of success with this fish.
If you plan on keeping corals in the Powder blue aquarium, and there is no reason why you shouldn’t, then the lighting will need to be adequate for the species/varieties chosen. LED illumination gives that authentic rippling light effect that is such a prominent part of the shallow reef experience. Although the current trend for high percentages of blue light in stony coral aquariums enhances the fluorescent proteins in their tissues, lower Kelvin ratings will afford a whiter light that will showcase the fabulous colouration of the Powder blue as well as faithfully recreate the shallow water in which this fish is commonly encountered.
Aquascaping: Powder blue surgeonfish adore swimming space. In this system, building a shallow incline of reef at about 30 degrees to the horizontal affords plenty of open water and yet still lots of rocky substrate over which the fish can browse for algae. Alternatively, you could opt for a horizontal arrangement of rock with one or two sand or rubble patches that would recreate the reef
flat zone nicely. Corals can be widely spaced giving focal points of interest with plenty of exposed rock over which the fish can browse.
Quarantining is a hard process to argue against for any fish, saltwater or freshwater, but reality dictates that few marine aquarists have the budget and space to establish a system into which fish can be placed, observed and treated and therefore don’t own one. Lack of quarantining is another one of the reasons why a UV steriliser is an essential piece of kit for the Powder blue.
Most fishkeepers consider keeping Zebra plecs and many would like to breed them. But whatever your goal, you'll need to know to look after them, says Julian Dignall.
The only thing black and white about the Zebra plec is its beautiful markings. Pretty much everything else is subject to myth, opinion and misinformation.
This, as well as the beautifully contrasting stripes, do add to the somewhat legendary status the Zebra plec, Hypancistrus zebra,
Depending on whom you speak to, the Zebra plec was discovered by anglers somewhere between the mid 1970s and 80s. It was given an L-number, L046, in 1989. The stripes of the Zebra have come to represent a new wave of catfish keepers, and it’s a flagship species for the now undeniable fishkeeping tribe that are L-number keepers and breeders.
The Zebra plec is endemic to the middle of Brazil’s Rio Xingu (pronounced sheen goo) and is among the catfish species at risk from the Belo Monte dam.
It lives at a depth where the surroundings are, at best, pretty gloomy, if not completely dark. It lives in the cracks, gaps and natural caves found in the very specific type of rock found in the river.
This is dark brown to black hard igneous rock that, in shallower water, is set in tan-coloured sand. There is very little submerged wood, there are virtually no plants and the water belts through the area at a rate of knots. Many of these areas are rapids and the water is highly oxygenated.
Exports of tropical fish from Brazil are governed and policed by the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA). IBAMA produces a so-called positive list of fish species and those are the ones that may be collected and exported into the global ornamental fish trade. Hypancistrus zebra has not yet appeared on it and is illegal to export from Brazil.
When you encounter one for sale it will either be captive-bred or will have been smuggled out of Brazil and exported, typically, from Colombia. They range from around £95-£150. This activity, as you may imagine, stirs some debate among fishkeepers. Even if such a wonderful species is at risk of extinction in the wild, does that make it acceptable to fund the smuggling of them into our shops? That’s to say, 'rescue' them before they are wiped out.
Thankfully, the Zebra plec’s future looks a bit brighter than many of its Xingu river cohorts. Because of its small size, relative ease of breeding and status, it is bred and traded in most countries that have a decent aquarium hobby.
In the aquarium
Keeping Hypancistrus zebra is straightforward, especially with captive-bred stock. When this species was first being bred in aquaria, arguments raged over how to best keep and breed it. Some polarised views were initially stated, but it turns out most folks were right, even if they had different points of view, because this species can live in a range of water conditions.
So, the hard water proponent was no more right or wrong than their softer water advocate. It has been bred in really quite hard water with no ill effects, though most spawns are in about pH 6.5-7 with moderate to no hardness.
I accept that breeding fish isn’t everyone’s cup of tea. It’s not a view I subscribe to personally, but I get the fact that people just want to look at their fish rather than reproduce them. However, in the case of the Zebra plec the majority do wish to breed them.
This may be for any mix of anticipated financial gain, fishkeeping kudos or the positive feeling gained from furthering the chances of this species’ ability to survive for future generations. So, let’s talk about how to keep them so that they breed and then, if you remain convinced you don’t want to breed them, you still have the intel on how best to keep them
Provide warm, oxygenated and clean water. Aim for a neutral pH, a water temperature of 86-88°F/30-31°C and have at least two power-driven filter outlets that mix in atmospheric air with the water flow. Clean water means both a decent power filter and at least 25% water changes.
Consider using plants and bogwood to replicate the natural habitat.
Feed them right
Feeding is more a matter of physics than biology. Zebras are not large plecs and you can keep a group in a relatively small tank. However, with all that filtration in play (see box above, right) food can get blasted around the tank and filtered away before the fish get to eat.
This is where some trial and error with aquascaping comes in. Play around with rocks so that there are some open areas of gravel where food collects. Even better would be near caves. If you can, do this in such a way as it’s easily accessible.
It may sound obvious, but be really careful moving rocks around with plecs in the tank. It is easy to trap or squash them, especially if you are stretching or off balance.
Aim for an aquarium that allows food to sink to quiet pockets away from the current, where the plecs can feed over a ten to 15 minute period once or twice a day. The choice of food is important. Flake or floating foods won’t do well in that kind of current, so sinking tablets made from flake or algae tabs will work, but Zebras need a lot of protein. I favour discus food, either frozen or granular. Select one that doesn’t expand a lot once placed in water. Many plecs will gorge on whatever food is available and something that expands to twice its size after being submerged for five minutes is remarkably lethal. This is especially true in plecs, as two thirds of their bodies are covered by rigid plates, so the only way the stomach can expand is downwards where there is only exposed skin.
Keep discus separate
The temptation to keep Zebras with discus is strong, as they share water requirements and similar diets. But the issue of water current can be overlooked. If you’ve got a filter that provides lots of dissolved oxygen (but without the kind of current that would scatter the discus around the tank), then this might work but it’s a bit hit or miss.
If you’ve a central system, then keeping Zebras in one tank and discus in another in the same system would work well, as you can add a pump/filter to the Zebra tank to create the extra current, but I’d suggest keeping these two fish apart in the main.
I like to keep plecs in oversized tanks because it means I have a lot more flexibility when it comes to looking after their water. For example, I have a group of five Zebra plecs breeding in a tank that has a 91 x 46cm/36 x 18" footprint and is 38cm/15" high.
In this is 2mm bore gravel to a depth of about 1". I mix black and brown gravel to get a look that I like and it appears the Zebras are, at least, not objectionable to. The black and white fish look fantastic against what is not only attractive, but reasonably natural substrate. On top of this, I have lots of breeding cave pipes and then slate and lateritic holey rock.
Zebra plecs won’t breed unless caves are present. These are commercially available or you can make your own. As a rule of thumb, I put two caves in for every adult fish. This is seen by some as overkill: some authors have one cave. However, I note a lot of aggression over caves and the alpha male will always pick the one that suits him best. So, if there are others available, the fighting is toned down a bit and, like me, you might be lucky and get two pairs spawning. This is relatively unusual, and it’s more common for males to breed with more than one female, a few weeks apart, but in the same cave. Females will live near the male’s cave, and so I like to provide rock cover over the caves that are thus in shade.
The temptation is to have them in full view so you can monitor proceedings, but it’s more important to have the cave mouth perpendicular to the current and for all the adult fish in the tank to be able to come and go from their places of rest without too much aggro.
Get the décor wrong and adult male Hypancistrus can seriously injure and kill each other. However, many people buy captive-bred Zebra plecs and they tend to be a bit smaller and not yet mature. Thus, such aggression has yet to manifest itself and can be avoided altogether by adding refuges as the fish begin to mature.
Sexing your zebra plecs
In well-conditioned, mature fish, sexing is straightforward. Applying these observations to fish less than about 80mm SL or that have not been in captivity for long will give variable results.
1. Full-grown male Zebro plecs are about 10-15% larger and bulkier than females.
2. The male’s interopercular odontodes that have grown from the fish’s cheek under the eye are longer — more than two times the width of the eye.
3. The male’s leading pectoral fin spine has orange-tipped odontodal growth of a similar thickness, if not length, to the cheek spines.
4. Males have heavy-set heads.
5. When viewed from above, males have a straight line from the base of the pectoral fin spine to the caudal peduncle.
6. Flip them over and examine their pinky-white undersides: males have pointier bullet-shaped genital papillae.
7. Females are generally slighter.
8. While females develop cheek and pectoral fin spines with maturity, they are shorter and less noticeable than the males’.
9. Females have a convex, curved outline from the base of their pectoral fin spine to the caudal peduncle (broadest in the midriff where eggs will be developed).
10. Underneath, females have a much less defined, but broadened genital papillae.
Much debate surrounds spawning triggers. Some authors report that not cleaning the filter — therefore slowing the water current a little — along with skipping a water change or two followed by increased water changes triggers well-conditioned pairs to spawn. Many say they will start spawning when mature given good water conditions. Certainly once they do start they will continue for years.
Often the first batch of yellowish orange eggs will be infertile and not hatch. This commonly happens with many plec first timers. It’s just a sign to keep doing what you’ve been doing — within a month, they will try again, maybe sooner.
The male will normally guard the eggs in the cave and often the first an aquarist knows they’ve bred is on seeing some delightful mini Zebras scooting around the tank, typically under stones.
If disturbed or inexperienced, the male may displace the eggs out from the cave. In this situation, or where you want to micro manage the eggs hatching, then an in-tank nursery is required. This can be a net mesh box or a more sophisticated plastic box, but the important things are that it shares water from the parent tank and is easy to clean. Place an airstone close to the egg clutch to simulate the fanning of the male’s fins in the cave.
When they hatch, youngsters will have unfeasibly large yolk sacs. It is only when these are consumed that you should start feeding. Crush whatever you’re feeding the adults and consider sinking tablets too. They are not hard to feed and even at this small size will eat dry foods eagerly and regularly. For best results try to feed twice a day or more. Clean the nursery at least daily, it needs to sparkle.
However, I prefer the hands-on dad approach and Zebra plec dads do a great job of getting 20 or so youngsters out of the cave. At this size they will forage and eat with the adults. They’re slow growers and unless you pay them a lot of attention in terms of feeding, space and water quality, getting them to grow more than 1cm every 6-8 weeks will be a challenge.
Zebra plecs are now bred in commercial numbers and these turn out beautiful clean fish in number. Also, shipments of wild-caught fish tend to have more males than females (it’s easier to collect males from the wild as they tend to be in a cave), but with captive-bred fish, it is more like parity. Because these are high-end fish, professional breeders know they must be kept in high quality surroundings to ensure they grow on well and fast.
Zebra plecs produce about 20 eggs and spawn every couple of months. These figures can be improved a little with ultra-attentive care but serve as a good indication. So, one pair could produce about 120 offspring a year. Let’s call that 100 once you take into account culling of inferior fish and the odd accidental loss for whatever reason. Now you need another year to bring them on. That’s running, say, eight tanks for two years before you start selling them. That can be done, but selling them in twos and threes to private buyers isn’t going to fund that Porsche anytime soon.
To make it a business, you’re going to need, say, 100 pairs and several hundred tanks — most of which you’ll be running for a year or two before any selling occurs. Bear in mind that a £100 retail fish might wholesale at about £40 and you don’t make any margin on shipping. Then factor in shipping disasters and so on. At some point in time, heat and food makes it more viable to attempt such an endeavour in a tropical country rather than in chilly old Blighty — unless you really scale up the operation or transport costs rocket.
This is the model being utilised by specialist commercial breeders and I think that given the beauty of the Zebra plec, will ultimately mean we continue to see this species offered for sale irrespective of what man-made catastrophe may, or may not, befall its wild cousins. This is also why I mention breeding this species for yourself. You can get to the stage where you and a group of friends have a decent population of these things and can trade with other groups. Isn’t that a good thing?
Given what I’ve said, perhaps seeking experience, cutting your teeth on less expensive Hypancistrus is a good starting point. If your ambition to keep
these wonderful black and white rock star plecs remains, you’ll be able to give it a worthwhile go and do it in a planned manner. Then you can dream of that first sight of baby Zebra plecs in your tank. That experience is a special thing.
Scientific name: Hypancistrus zebra.
Pronunciation: Hype an siss truss.
Common name: Zebra plec.
Lifespan: 15 years plus.
Spawning age: Around three years.
Water chemistry: 5.5-7.5 pH.
Why not take out a subscription to Practical Fishkeeping magazine? See our latest subscription offer.
Don't forget that PFK is now available to download on the iPad.
There are many uses for carbon, especially in the fishkeeping hobby, yet itâ€™s often misunderstood, writes Nathan Hill. Hereâ€™s your chance to get to know this chemical element like the back of your hand.
Look in your tank, it’ll be heaving with carbon. Look at the back of your hand, that’s carbon heavy, too. In fact, carbon permeates all aspects of our lives, from peanuts to pencils. It’s only right we should find many uses for it, and a lot of those uses are aquarium-based.
Carbon is, in its simplest form, the chemical element C. If you know your periodic table, you’ll recognise it as the sixth element down the line. It’s naturally occurring, bountiful and incredibly useful.
You’ll already be deliberately using carbon in some form, whether you like it or not. It makes up a vital ingredient in food, such as protein.
Your fish will be breathing it out through their gills as carbon dioxide. Your plants will be guzzling it up as food to make sugars — C6H12O6. Carbon is absolutely inescapable.
For the best part, most of us will know carbon as the black granular media we cram into our filters. You might have pads impregnated with it, or you might have a pack of it loose, ready to be loaded up into a mesh bag and dropped in the tank somewhere. That’s all well and good, but what does this kind of carbon do? How does it work?
Carbon works on adsorption (not absorption), which is a way of saying it is incredibly sticky to certain chemicals. Once certain chemicals come in to contact with carbon, they are grabbed by it and retained — at least for a while.
This is why the surface area of carbon is all-important. The more it has, the more waste it can hang on to. This is where activated carbon has the advantage over regular carbon, in that the activation process massively increases the number of tiny pores in it.
Carbon is excellent at removing organic chemicals from the water. Now, don’t confuse organic chemicals with the three usual suspects: ammonia, nitrite and nitrate. These three are inorganic compounds, and carbon has no interest in them. If you’re adding carbon to deal with an ammonia spike then you’re barking up the wrong tree.
The two chemicals that carbon excels at pulling from tanks are phenols and tannins. These are produced from a variety of sources, including the metabolic waste of fish, leaching from wood, the breakdown and decomposition of faeces, plants and uneaten food, and more. You’ll recognise them as chemicals that discolour the water, giving a yellow or brown tint, and in the case of phenols, emitting a 'tanky' smell as well.
In this respect, carbon is indispensible in polishing the water and keeping it gin clear. For marine keepers, those phenols can play havoc with marine invertebrate growth, where for freshwater they’re more likely to build up and cause eventual malaise in the fish.
It’s essential to get carbon in the right place in the filter as well. If it is placed too early then it runs the risk of becoming biologically active; that is to say that it will start to get smothered in nitrifying bacteria. If that happens, you lose surface area on the carbon and it becomes redundant. Even worse, when it comes to changing it, you’ll be pulling out a huge glut of your biological filter with it!
The carbon should always be a polishing agent at the end of the filtration process, never at the start. If you have a canister then you want to go foams (mechanical filters) then biological media and then carbon, not the other way around.
How much you need to use varies, based on your tank, the inhabitants and the quality of the carbon. The best carbon you can get has the highest surface area to volume ratio.
If faced with a choice of a few varieties, opt to buy the one that boasts the most surface area compared to its weight. Some brands will happily advertise their surface area on the packet, and this is a good sign that they know what they’re talking about.
Carbon as filter food
In marine tanks, carbon is frequently utilised as a way of encouraging and feeding the growth of anaerobic bacteria.
Anaerobic, heterotrophic bacteria — the kind that guzzle nitrates when there’s no oxygen around — require a carbon source in order to function, unlike the autotrophic bacteria in our filters that convert ammonia and nitrite. That carbon can take a few forms. Some newer products are appearing that use a starch as the carbon source (and with excellent results, I add).
The traditional method is to add a liquid carbon, namely alcohol, to the tank. The alcohol we have in drinks like vodka is ethanol — C2H5OH — which is just right for the bacteria to use. It might seem odd, but, yes, adding the correct amount of vodka to a marine tank with plenty of live rock will reduce both nitrates and phosphates. Different aquarists have had successes with different rates of vodka dosing, but methods that have worked have involved between 0.1 and 0.9ml of 40% alcohol vodka per 100 litres to a tank daily.
Of course, vodka isn’t the only way to get carbon into a tank, but it has given good results so far. Some aquarists have experimented with other ‘everyday’ sources such as vinegar, rice and sugar. The angle here is that these methods introduce carbon to the water column. The catch with that is that there’s every chance an overdose will poison fish. Uh oh.
That doesn’t spell the end for carbon dosing. In the wake of dangers presented by liquid carbons, the market has increasingly steered towards solid carbon sources, namely starches and other carbohydrates, or ‘dry vodka’ dosing. Don’t be deceived by the 'vodka' part in this latter claim, as vodka is not an ingredient at all; it’s just a direct reference to the fact that it’s doing a similar job to vodka dosing methods.
Solid carbon reverses the roles a tad, and rather than bringing carbon to the bacteria (who usually live in rocks or substrate), this method entices bacteria to grow directly on the carbon source. Most solid carbon methods employ the use of a reactor, which is a large tube through which the water from the tank passes over the carbon filter medium. This has the effect of tumbling the media and keeping it in suspension, and as the carbon then develops a film on its surface — made up of nitrate and phosphate-guzzling, carbon-hungry bacteria — this tumbling action knocks the excess biofilm off.
The film now comprised of bacteria and fixed waste, is then either removed through the action of a protein skimmer or is even consumed by corals and other invertebrates in the tank.
Flow rate is essential when it comes to solid carbon dosing. Too fast, and the filter doesn’t become established; too slow, and everything gets smothered in biofilm. Solid carbon is still a fast growing part of the marine fishkeeping hobby.
Carbon as plant food
Carbon is essential for plant growth, but it needs to be in the right form for plants to uptake.
I’m sure most of us are well aware of what photosynthesis is, but to briefly recap it’s the action of plants that utilises water, light and carbon dioxide in order to create carbohydrates and oxygen.
In the aquarium, carbon is added in one of a couple of ways. The preferable method for many is to add carbon dioxide to the water, through the medium of tiny bubbles until it forms a solution in the water. As humans, we guzzle down the stuff as the main ingredient in fizzy drinks: carbonated water. One alternative name for carbonated water is carbonic acid, and that’s one of the reasons why soft drinks are so acidic: because you’re literally drinking acid. Add too much to the tank, and it’ll drop to dangerously low pH levels, which is why a thorough understanding of the use of CO2 in planted tanks is essential and why so many 'budget' CO2 kits can, in fact, be wildly dangerous.
In absence of adequate carbonic acid, plants in tanks will try to find their carbon from elsewhere. Calcium carbonate, the chemical responsible for the alkalinity and carbonate hardness in your tank, is sometimes forcefully secured as an alternative source and can result in faint chalky deposits on plants.
Carbon can also be added in liquid form, and the current vogue of plant growers is the use of glutaraldehyde, CH2(CH2CHO)2. This form of carbon is not without its risks. In fact, in its everyday use, it’s a steriliser for dental gear, a wart cure and a fixer for tanning leather. Overdose it and it’ll ravage fish and invertebrates.
Carbon as dechlorinator
One area where carbon is outstanding is in the removal of chlorine, chloramine and some heavy metals. With that in mind, it’s a pristine choice to treat any incoming tapwater before use with fish, and it can be considerably more economical than using liquid dechlorinators (some of which don’t even remove chloramine!)
To put into context, a typical 500ml bottle of dechlorinator will cost me about £9 and treat around 19,000 litres. Ten bottles will treat about 190,000 litres and cost me £90. A typical carbon dechlorinator treating 350,000 litres can be picked up for around £90 to £115. That’s a big saving…
A carbon dechlorinator goes inline on your water supply. Some need to be permanently installed, which is great for domestic supplies as well as tanks or, if you prefer, you can buy units that simply go inline with hosing.
You pay your money and take your choice.
The lifespan of carbon
Due to its adsorptive nature, carbon eventually exhausts itself when its entire surface is coated in waste. Anyone that tells you an exact lifespan for carbon is a barefaced liar, as each and every tank will have a different volume of waste inside it. In some cases, the carbon might be exhausted within three or four weeks. Most users will have it in their tank for up to six week stints at a time, after which time we generally accept that it can start to leach some of what it has taken out back in to the water.
In that time, you’ll find that carbon is very good at removing chlorine; chloramine; phenols; dyes; some heavy metals such as tin, mercury and iron; and fish medications. Indeed, that’s one of the best reasons to have carbon on hand: to whisk out any accidental overdoses or to remove residual medication after a disease treatment.
PFK answers your frequently asked carbon questions
Where is carbon from?
Carbon comes from lots of different sources. On a universal level, it is formed in the death throes of exploding stars and blasted out into space during their final cough.
For aquaria, granular carbon can come from animal bones, peat, coconut shells, wood and bituminous or lignite coal. The source can have a big effect on just how good a carbon is in action. Effectively, all carbon is just charcoal taken to the next level by cooking it.
To create carbon, these ingredients need to be heated to thousands of degrees centigrade, which gets rid of the impurities and chemicals you don’t want, as well as increasing the surface area. Surface area is essential, as the more you have, the more your carbon can interact with water and the more chemicals it can remove.
For filters, it’s generally accepted that carbon made from bituminous coal is the best. In fact, it’s the choice of water purifiers the world over, and if you have a BRITA filter, then you can bet your boots you’ll have this kind of carbon inside it.
Carbon dioxide is sometimes harvested from furnaces, breweries and other ‘recapture’ sources but is also the by-product of burning coke. It can even be made with certain chemical reactions, when acids meet base substances. The kinds of carbon found in solid carbon pellets are often specifically processed starches created in laboratory calibre conditions.
Can carbon be reactivated in the oven?
No. The myth goes that you can place your old carbon in the oven, turn it up to full heat for a few hours and the carbon refreshes. Unless you have an oven that goes up to 2,000°C or more and have access to facilitators like acid and oxygen, then it’ll do nothing. Besides, who can afford to run an oven like that with today’s energy costs?
Didn’t you say it removes organics? What about trace elements?
Admittedly, it’s not just organic chemicals that carbon removes, and as such it has been implicated as a cause of problems to some fish, even as the cause of a disease.
It’s true that carbon is unselective in what it removes. But because of this, it’s had the finger pointed at it for removing trace elements and even micronutrients that fish need. One spurious extrapolation of this idea is that carbon might even cause head and lateral line erosion (HLLE) or hole in the head (HITH) disease. This was touted as mantra by many aquarists for years until further research suggested that it might instead be certain ferrous chemicals used in phosphate removers that were causing the problem.
Either way, the amount of trace elements that carbon can be accused of removing leaves it off the hook when it comes to causing illness.
Do I still need to perform water changes?
Oh yes. Carbon is not a water change in a bag. Despite it pulling out some chemicals, especially dissolved organics, you will still have a build-up of nitrate and a depletion of minerals that need replacing.
Does it leach phosphate?
Yes, the one downside to activated carbon is that it will increase phosphate levels in the tank, which in turn is implicated in the boosting of many kinds of algae in everyday aquaria.
Really cheap, low quality carbon, heaving with ash, will even boost pH in your tank, sometimes dangerously so. As luck would have it, you’ll usually find that these cheaper brands will also be the worst for leaching phosphate, so with carbon it’s often a case of getting what you pay for. If it looks too cheap to be true, it probably is.
Organic or inorganic?
Whether a compound is organic or not rests heavily on carbon, though not without exceptions.
Most organic chemicals that we can think of usually involve carbon in tandem with hydrogen. So, proteins (carbon, hydrogen, oxygen and nitrogen) and sugars (carbon, hydrogen and oxygen) are among the many organic chemicals that we come across.
It’s not quite enough to class carbon as the single factor, however, and not everything carbon-based is organic. A diamond, for example, is pure carbon, but as inorganic as it gets. Carbon dioxide (carbon and oxygen) is another inorganic carbon form. There are even a couple of organic compounds that do not have the hydrogen bonding, yet they are still classed as organic.
It’s rare that you’ll come across the phrase organic or inorganic carbon in the hobby, but if you do, just know that what we’re referring to is the presence or otherwise of both carbon and hydrogen in a compound!
Why not take out a subscription to Practical Fishkeeping magazine? See our latest subscription offer.
Don't forget that PFK is now available to download on the iPad.
With comic canine faces, bird beaks, quirky lips and more facial expressions than Jim Carrey, pufferfish can evoke a smile from even the sourest of sourpusses, admits Nathan Hill.
The most enduring, admired and adored fish in the hobby have to be the many pufferfish varieties. Traditionally speaking, the challenges of keeping puffers have been split into three categories: size, salinity and temperament.
The size issue is mostly a marine problem. Huge Dog-face and Porcupine puffers are far and away the most appealing, but also the largest, as though their cuteness is directly correlated with their size. These bloated jesters, reaching 50–60cm/20-24" or more, are not for the starter aquarist. Nor many experienced ones.
Salt has been the bane of many puffers, mainly because there seems no 'folk wisdom' consensus on exactly which species require brackish conditions, full-blown marine or fresh.
For years, there has been confusion about exactly how much salt to give a Figure eight or Green spotted puffer, resulting in errors, white spot and death.
And lastly, there’s temperament. Pufferfish are well armed, with slicing ‘beaks’ and a tenacious lust to bite absolutely anything that can be bitten. It’s as though they explore the world with their teeth as a primary sense organ, such is their propensity to chomp.
This means that almost everything that has been housed alongside traditional pufferfish has ended up either shredded or decapitated, resulting in lightly stocked tanks and heavy disappointments.
This all changed when the world’s tiniest bundle of adorable appeared in the hobby. The Dwarf Indian puffers, also known as Pygmy puffers and Malabar puffers, Carinotetraodon travancoricus, were a revelation for the everyday aquarist, being small, entirely freshwater and not quite the relentless psychopaths that we naturally expect of any of their relatives. That’s not to say they’ve been problem free.
In some cases, enthusiastic buyers plunge them into community tanks where they immediately race over to say 'hello' to the resident Siamese fighter in the same way my Scottish terrier tries to say 'hello' to squirrels. A little foresight regarding tank mates can go a long way.
Avoid wild fish
The home aquarist should be mindful to try to avoid wild caught specimens when purchasing pufferfish, due to the impact that the hobby, along with other factors, is having on wild stocks. Though some researchers want to classify Carinotetraodon travancoricus as endangered, the IUCN (International Union for Conservation of Nature) Red List sees it fit to class them only as vulnerable. Overfishing for the hobby is cited as one reason, though damming in India, aggressive agriculture and deforestation all plays a part.
The figures suggest that over a five-year period, wild populations fell by up to 40%. Ask your retailer the origins of the fish before buying, as this is one situation where farmed or locally bred fish may indeed be preferable.
Pygmy puffer popularity means that you’ll find these fish in dozens, if not hundreds, of stores around the UK.
Check for plumpness and condition before buying, as some are sold in an undernourished state. If you can, request to see the fish feeding before making your decision.
Being small and readily available, expect to pay anywhere upwards from around £2 per fish, and ask if there are bargains on buying numbers. Remember to keep eyes open for farmed puffers over wild!
Are pygmy puffers poisonous?
Probably not. At least, not in the same sense as their larger Fugu cousins. Puffer poison is well understood in popular culture and not just as a recent phenomenon. Even Captain Cook had a run in with the stuff when half of his sailors fell ill from eating puffer flesh and all his pigs died.
The poison in question is Tetrodotoxin, or TTX, a frankly horrific neurotoxin to succumb to. Eat the wrong bits of Fugu and your body shuts off while you remain conscious. All the involuntary muscles such as the heart and diaphragm stop, and you die. You don’t need much of it either. As much as you can carry on the head of a pin will easily kill an adult human.
Female puffers are thought to be more toxic than males, with ovaries being able to store more of the poison than testes.
Marine puffers might make their own toxin from symbiotic bacteria. However, they might gain it through eating other organisms that produce it such as the algae on the shells of certain shellfish. In the confines of a tank, without access to toxic food sources, there’s little reason why we should expect Carinotetraodon to become too much of a health hazard. That said, you still wouldn’t want to eat one. That’d just be silly.
How to set up a Dwarf Indian pufferfish tank step-by-step
I took the chance to rig up a Fluval Fresh 85 l/19 gal system that I have been sat on for a while for my pufferfish foray.
Once filled with sand and décor, I calculated the volume to be closer to 60 l/13 gal of water, which is perfect for a shoal of six Carinotetraodon travancoricus.
Here’s how I did it...
1. The tank is cleaned and placed on pieces of trimmed absorbent matting to balance out any irregularities between glass and cabinet. The filter and lighting are then installed.
2. Two pieces of lava rock are added at one corner to act as the foundation to build up my ‘riverbank’ edge. I have chosen the side with filter pipes to help obscure them.
3. A single central piece of presoaked Redmoor wood is added to provide an intricate structure for the puffers to explore. It is vital to soak this wood in advance to stop floating.
4. Approximately 15kg of thoroughly washed aquarium silver sand is added to the foundation rocks to create a deep bed. The sand is smoothed down with a credit card to shape.
5. A large flat cobble and smaller subordinate cobbles are added to the middle of the tank. They help to reduce 'sandsliding' and create a transition from flat to bank.
6. Loose twigs are added for effect, and the two marginal pond plants, Equisetum japonicum, are removed from their pots, the roots rinsed and then added to the bank to break the surface.
7. The tank is filled and six bunches of assorted Vallisneria sp. are divided up into individual plants and added to the display using pinsettes, but only along the back and side.
8. The heater is added, and floating ‘nuisance’ plants and algae, taken from a retailer’s pond plant vat, added to the surface. These help reduce the impact of the LED lighting.
- Fluval Fresh 85 l/19 gal aquarium with filtration, heating and LED lighting
- 15kg aquarium silver sand
- 1 medium piece Redmoor wood
- Approximately 6kg of lava rock
- 4-5kg of assorted cobbles, including one large flat cobble
- 2 x Equisetum japonicum pond plants
- 6 x bunched Vallisneria
- Floating duckweed and algae
On the whole, keeping Carinotetraodon travancoricus is so easy you’ll be left wondering why you don’t have tanks of them all over the house. The only single, difficult aspect is feeding, but as long as you’ve got a freezer, then you can easily overcome that obstacle.
By way of return for meeting their requirements, they’ll reward you with some of the most comedic antics that any fish can muster. Give them time and they might even start to breed for you too, without any extra outside help.
Even an old sourpuss like myself has to admit that I spend way more time watching my puffers during the evening than any other fish I’ve owned, and to date I’ve never been able to second guess quite what they’ll do next. Join the pufferfish camp, and I doubt you’ll ever look back.
Dwarf puffers hate flake foods. Offer it and they’ll look at you with indignation. They’ll potter across for a curious scan over then let that flake slump to the base, where it’ll sit festering.
Bloodworm is never refused, either live or frozen, and other foods are accepted according to individual fish temperaments. Some will also gorge on frozen Daphnia or Cyclops, some will only accept live.
The same applies to brine shrimp and Tubifex. Invest in a mixed pack of frozen foods, such as a quintet with five different ingredients and see which your fish prefer.
Many larger puffers suffer from dentistry issues in aquaria, as their sharp beaks (actually four fused teeth) aren’t worn down from foraging food and crushing mollusc shells. Carinotetraodon succumb less, but it is still something to be aware of, and their diet should include creatures with a hard shell that needs biting through.
Snails are a good choice, and if you know other fishkeepers, I’m sure they’ll be happy to let you take some of theirs away.
Daphnia are another option in helping keep teeth trim and you should make a note to pick up some live ones whenever you see them offered.
Their tank need not be particularly big, unless you’re housing a shoal of them, which you definitely should. Wild Dwarf Indians like to move in large collectives; this is why they’re so easy to catch, and they have a migratory, cyclical lifestyle.
Despite their waspish nature to some other fish, they do enjoy the company of their own kind. Because of their adult size of a mere 3.5cm/1.4" for wild caught specimens and an optimistic 2.5–3cm/0.9-1.2" in aquaria, they’re suited to anything around the 60cm/24" long mark.
Keeping them at a density of one fish for every 10 l/2 gal of swimming space is a pretty safe bet, as long as the sex ratios aren’t skewed heavily towards males. Males will bicker and squabble, and there’s some evidence to suggest that in a young group, the first fish to take male sexual development will release pheromones to inhibit the sex changing of its contemporaries.
Water quality needs to be pristine, and an oversized, but underpowered filter is advised. Their wild waters are slow moving and they don’t have the body shape for turbulence. Where other fish may be streamlined and hydrodynamic, cleaving through water like aquatic gazelles, puffers tend to have all the manoeuvrability of an inebriated cow. Opt for filters that can spread any return flow to the tank over a wide area, minimising any fast torrents or eddies.
Biologically speaking, the filter needs to be big as the fish are messy. With vast appetites and an affinity for spitting chunks of food out, expect pollution to be erratic in poorly managed tanks. Getting in to the habit of removing uneaten scraps with a net or siphon hose after each meal is good practice.
Water chemistry can be slightly acidic or surprisingly alkaline, with records of the fish being collected in rivers anywhere between 6.8 and 8.3 pH. Hardness is equally diverse, and anywhere between 5 and 25°GH they are fine.
Temperature should sit between 22 and 26°C/72 and 79°F, though wild samplings have revealed fish from rivers in excess of 33°C/92°F during summer months.
Decoration is where the aquarist should be indulgent. Unlike many fish that glide about like automated submarines, oblivious to everything around them, Dwarf Indian puffers need to be enraptured at all times. To them, the world is one fascinating place to be explored on the smallest level, through the medium of eyes and teeth.
Wild habitats involve plenty of leaf litter, marginal vegetation and fallen branches, but in aquaria, anything that can be explored will keep them occupied. Be creative with caves, make dense thickets of plant and add as many anomalies as you like — I’ll even forgive the air-powered scuba divers — and they’ll love you for it.
Aim to break up line of sight in case any bickering does occur. Puffers tend to be angry only for as long as they can see the object of their rage. The moment it’s gone, they’ll swan off in child-like wonderment to look at a plant stem, piece of gravel or upturned leaf instead.
Sexing the dwarf puffer
Sexing Carinotetraodon revolves around colours and markings. 'Wrinkly' eyes, actually a scribble of fine lines around the orbits, indicate males, as does the presence of a clear, dark line that runs lengthways over the belly. Males supposedly have a slightly yellower underside, too.
Add other fish at your peril!
Anything slow or cumbersome will be nibbled, and even fast fish such as danios can receive the occasional sly nip.
Shrimps are generally a no go, unless you want them dismembered, and snails are right out; some keepers have managed it, but they’re certainly the exception rather than the rule. Unfortunately, each fish has an individual temperament, so I can only advise you to err on the side of caution. I’ve seen Dwarf Indians kept with guppies, gouramis, catfish and even crabs, but I would only ever consider species-only tanks.
Why not take out a subscription to Practical Fishkeeping magazine? See our latest subscription offer.
Don't forget that PFK is now available to download on the iPad.
Mollies have a mystique that sets them apart from other commonly traded livebearers, but with a reputation for being difficult to keep Neale Monks' A to Z guide into their weird and wonderful world is a must-read.
Mollies are really very adaptable fish, but to keep them well you really do need to know something about them.
A small molly is much bigger than the average guppy, and some of the biggest molly varieties are real giants. They are often described as more suited to brackish water systems than community tanks.
A is for Amazon
The Amazon molly is a very bizarre fish. The species is for all practical purposes female, but females mate with males from other molly species as and when the opportunity arises. Fertilisation doesn’t occur, and after mating all the male’s sperm does is trigger the development of the female’s eggs. The eggs have a complete set of genes already, identical to those of the female, so effectively the species clones itself with each female molly producing a batch of daughters genetically identical to herself after each mating!
B is for brackish water
Mollies are common in saline habitats, including brackish ditches and lagoons. Some may even be found in marine environments, albeit in very shallow water; for example, around the roots of mangroves or artificial habitats like harbours. A few species, like Poecilia gillii and Poecilia vandepolli, get bigger and show brighter colours in brackish water but you’re unlikely to see species such as these in tropical fish shops.
The mollies in aquarium shops are hybrids that do well in freshwater — provided other parameters are good, particularly water quality and hardness. Still, wise aquarists will stock the molly aquarium with salt-tolerant plants and tank mates, just in case a little salt is needed for good health.
C is for caves
One variety of Sailfin molly, Poecilia mexicana, inhabits the limestone caves of Mexico. Unlike a lot of cavefish, cave mollies have eyes but their habitat is completely dark so they need to find their food and one another by relying on their lateral line. Instead of algae they feed on sulphur bacteria, insect larvae and even bat droppings!
D is for dorsal fin
Male mollies often raise their dorsal fin when threatening rival males or trying to impress potential mates. Two species of molly have large sail-like dorsal fins, the Sailfin molly, Poecilia latipinna, and the Giant sailfin molly, Poecilia velifera. The size of the sailfin depends on environmental conditions; a spacious aquarium with good water quality and frequent water changes is needed for maximum development.
E is for extremes
Mollies are remarkable among livebearers for being adapted to a range of seemingly extreme conditions, including species that are tolerant of low oxygen levels, salinity levels above that of normal seawater and even high concentrations of hydrogen sulphide that would kill most other fish in minutes.
Ironically perhaps, some of these mollies are at risk of extinction. The Sulphur molly, Poecilia sulphuraria, is limited to a small area in Mexico where sulphur-rich springs feed into a number of streams and pools. As humans use more of the surrounding area for homes and farms, there’s less and less habitat for the Sulphur mollies. While they can live in ordinary freshwater, they can’t compete with regular mollies in such habitats so really do need their unique habitat to survive.
F is for food
While mollies are definitely omnivores that consume both animal and plant foods, the accent should always be on plant-based foodstuffs. Spirulina flake and pellets make good staples, while meaty things like bloodworms, though greedily consumed by all mollies, should be used sparingly: once or twice a week at most.
G is for Giant sailfin molly
Also known as Poecilia velifera, this species can get very big (around 15cm/5.9") and it’s the females that are the biggest. They are somewhat delicate and prone to stunting as well as opportunistic bacterial infections if aquarium conditions aren’t optimal. Needing very hard water to do well (at least 20ËšdH, pH 7.5), this species is probably easier to keep in slightly brackish water. Water quality needs to be good too, especially in freshwater aquaria.
H is for hybrids
When two species are crossbred, the resulting offspring are called hybrids. This easily happens with mollies, and hybrid mollies are probably very common in the trade particularly among the popular ‘fancy’ varieties. Dalmatian mollies likely inherited their spotted colouration from a spotted form of the Sailfin molly, Poecilia latipinna, while the Black molly is a hybrid based on Poecilia sphenops.
I is for islands
Many mollies are found in the Caribbean islands and several species are endemic to just one island or island group, for example, Poecilia elegans and Poecilia dominicensis to Hispaniola, and Poecilia vandepolli to the Lesser Antilles. Their tolerance of salty water allows mollies to colonise habitats closed to most freshwater fish, but that also makes them an invasive species if they’re accidentally introduced somewhere by people.
J is for jaws
Molly jaws can protrude forwards to make a sort of scraping tool ideal for rasping algae from plants and rocks.
While omnivorous in the wild and in captivity, it’s a good idea to ensure mollies get plenty of green foods to eat. In brightly-lit tanks there may be enough algae for them to eat, but this can be supplemented with Spirulina flake and other algae-based foods. Softened salads and veggies can be used too, with blanched lettuce and cooked spinach being particularly popular with most mollies. As mentioned before, minimise the use of meaty foods, especially rich foods like bloodworms. These would only be minor parts of their diet in the wild, and mollies tend to be healthier and live longer when given a predominantly plant-based diet.
K is for confusion (in Greek anyway)
Poecilia kykesis gets its name from a Greek word, 'Kykesis', that means 'a mixture' or 'confusion'. The name was a reference to the variety of mollies that had been lumped together as Poecilia petenensis.
In fact this species is one of several large Sailfin molly species that is greenish-silver in colour and inhabits freshwater and brackish water along the subtropical coastline of North America.
What is distinctive about Poecilia kykesis is the presence of a short extension to the lower lobe of the tail fin, similar to that seen on swordtails. On occasion these Swordtail mollies do turn up in the aquarium trade, and their care is similar to that of other Sailfin mollies. Needless to say, such similar and closely-related fish hybridise readily. So if you are lucky enough to get hold of Poecilia kykesis (or any other purebred molly species), it would be wise to keep them away from all other livebearer species so you can produce useful purebred offspring to pass on to other hobbyists.
L is for Liberty molly (picture above by George Farmer)
For many years regarded as a variant of Poecilia sphenops, this very pretty fish is now recognised as a distinct species, Poecilia salvatoris. Its common name refers to the similarity between the red, white and blue colouration on its fins and the colours of the American flag.
In aquaria Liberty mollies can be nippy towards other fish and aggressive towards one another. It’s best to keep them in a large group, with the females outnumbering the males.
M is for maximum size
Most aquarists will have read reports of female mollies that were 15cm/5.9” or more in length, but such giants seem rare in aquaria. Why is that?
One aspect is surely genetics. Breeders tend to be looking for colours rather than size, and fish farmers will make more money from fish that breed when young (and therefore relatively small) than those fish that develop more slowly (even if such fish eventually grow to be very big).
The end result is that farmed varieties of mollies are invariably smaller than their wild cousins. But diet and especially environment are likely to be factors too, and this can be observed in the wild as well as in aquaria. For example, Poecilia vandepolli from saltwater lagoons are substantially bigger than those in brackish water and twice as big as the ones in freshwater habitats!
N is for nitrate
Mollies seem to be peculiarly sensitive to nitrate, especially in freshwater aquaria.
Salt reduces the toxicity of nitrate (and nitrite), which may be one of the reasons that mollies often seem easier to keep in brackish water compared with freshwater.
As with many other nitrate-sensitive fish, such as dwarf cichlids, it is a good idea to aim for nitrate levels at or below 20 mg/l. Frequent water changes will help, as will lightly stocking the aquarium and feeding fish sparingly especially avoiding protein-rich foods such as bloodworms.
Fast-growing plants can remove nitrate between water changes, with floating plants being perhaps the easiest to grow and crop back as necessary.
O is for osmosis
When fish are placed in freshwater they tend to lose salts and gain water through a process called osmosis. The reverse of this happens in seawater; the fish gains salt but loses water. Uncontrolled, either can quickly lead to death; the fish either swell up with water in the first situation or become dehydrated in the second.
Mollies are euryhaline, meaning they can adjust their bodies to live in both fresh and saline conditions. In some cases they can live and breed perfectly well in full-strength seawater.
P is for Poecilia
There are at least 40 species currently included in the genus Poecilia, all broadly molly-like in shape and habit but varying in size and colouration.
Apart from the mollies, other members of this group include Poecilia reticulata, the guppy and Poecilia parae — a variable species notable for occurring in several distinct colour forms of which the Red melanzona morph is the one that is most commonly traded.
As they interbreed readily, it is important to keep Poecilia species separate if hybridisation is to be avoided.
Q is for quality
Water quality, that is! Mollies are a bit of a paradox when it comes to their suitability for new aquaria. In freshwater aquaria domesticated mollies can be delicate; in particular the fancy forms like Balloon mollies and such fish are best maintained in mature tanks with well-established biological filters.
On the other hand mollies can be quite tough when maintained in brackish or marine conditions, and historically Black mollies were often used to cycle new marine tanks. With the widespread use of live rock to mature marine tanks, cycling tanks with hardy fish of any kind isn’t recommended anymore.
R is for respiration
Like most fish, mollies respire by extracting oxygen from the water and pumping it through their gill cavities.
Mollies have the ability to put up with stagnant, oxygen-poor water longer than other livebearers. Mollies swim to the surface and pump the uppermost layer of water, which contains the most oxygen, across their gills. They can also increase the amount of haemoglobin in their blood to absorb oxygen from the water more effectively.
It’s not good to force mollies to work this way in aquaria, and if your fish spend a lot of time at the surface it could be a clue that circulation or aeration of the water isn’t adequate.
S is for sailfin
The males of several molly species have sail-like dorsal fins. Poecilia latipinna and Poecilia velifera probably have the biggest dorsal fins relative to body size, but even those on Poecilia petenensis and Poecilia kykesis are still substantial structures that dwarf those of the so-called Shortfin mollies like Poecilia sphenops.
The function of the sailfin is partly for display, but it’s also an encumbrance that makes life difficult for the male molly carrying it. So like the peacock’s tail, the molly’s dorsal fin is an honest advertisement of genetic fitness; a male molly must be strong and healthy if it has lived long enough to become sexually mature while carrying a giant fin that uses up nutrients, increases drag and makes swimming more difficult.
T is for tonic salt
Tonic salt is basically sodium chloride, i.e. cooking salt, but without the added iodine. When kept in soft, acidic conditions especially, mollies are prone to bacterial and fungal infections and small amounts of tonic salt helps to keep these at bay. A dosage of around one to two teaspoons per 10 l/2.1 gal of water is often recommended.
While useful, tonic salt used this way is inferior to a higher dosage of marine aquarium salt mix because it lacks the complete range of trace elements and buffering salts. If you’re setting up a planted brackish water aquarium, it’s better to use marine aquarium salt mix at a dose of about 4-6 g/litre (roughly a level teaspoon per litre) for a specific gravity of 1.002-1.003 at 25ËšC/77°F.
U is for unappreciated
The Balloon molly is a variety of molly that divides the hobby. It has a deformed spine and abdomen, but good quality specimens don’t seem to be any more disease-prone than any other domesticated, fancy molly variety. Wise aquarists keep them to themselves though, because they don’t compete well with standard mollies or indeed any other boisterous fish species.
V is for velifera
The biggest traded molly is the Giant sailfin molly, Poecilia velifera. Success with this species comes down to generous aquarium size, low-stocking density, excellent water quality, hard and alkaline water chemistry and an algae-rich diet. If these requirements are ignored, the species may still live but it often becomes stunted and the dorsal fin in particular may fail to reach its maximum size.
W is for water chemistry
Mollies need hard, alkaline water to do well and in the wild are rarely found in soft water. Aim to provide general hardness levels of 20ËšDH or higher and ensure the carbonate hardness is high as well, 10ËšKH or more, so that the pH stays steady between water changes, ideally around 7.5 to 8.5. Ideally keep mollies alone, but if you must keep them with other species choose ones with similar requirements.
The Brown hoplo catfish, Hoplosternum littorale, for example, would be a good choice as it comes from similar habitats and enjoys similar water conditions. It even tolerates slightly brackish water perfectly well.
X marks the spot
Many aquarists will be aware of the 'gravid spot', the dark patch that appears between the abdomen and the anal fin when female livebearers are carrying young. The patch itself is formed when the dark tissue of the uterus pushes against the thin muscle wall of the abdomen. Though clearly visible on small species like guppies, it isn’t so obvious on larger species like mollies, particularly ones with dark, intense or peppered colouration (like Black mollies or Dalmatian mollies).
Y is for Yucatan
This Mexican peninsula is a heartland of molly diversity, with several species being found there and often in the same streams and lagoons. Normally, closely-related species living together divide up their habitats so that they don’t compete with each other, and by living apart they don’t get the opportunity to hybridise. However, when scientists collected and examined four species of molly in Yucatan they found just four male hybrids, an astonishingly small number given they’d been collecting mollies there for more than thirty years! The authors suggest that each molly species has its own pre-mating behaviours that isolate it from other species; successful matings across species are consequently very rare.
Z is a good place to finish!
For such widely-traded fish, mollies are surprisingly poorly understood, but hopefully this feature has highlighted a few of the things that make them remarkable fish and well worth keeping.
Don't forget that PFK is now available to download on the iPad/iPhone.
Nathan Hill explores the origins, benefits and breeding of one of the hobbyâ€™s biggest game changers, the Amano shrimp.
I’m not sure aquascaper Takashi Amano realised just how much he’d change the face of fishkeeping when he asked a local collector to round up a few thousand bland, colourless shrimp for him. Now, three decades on, there are few tanks that haven’t felt the presence of these hard-working, tenacious invertebrates.
My own experiences with these fastidious grazers have been positive through and through. They’ve saved aquascapes as well as my large retail displays (in my aquatic store manager days) and I’ve even had them breed, which is something I didn’t know was remarkable at the time and something that many Amano shrimp adherents will vehemently deny; more on that later.
The true Amano shrimp is Caridina multidentata, but you might see them bandied about under their synonym of Caridina japonica. Certainly when Takashi stumbled across and popularised them in the 1980s, that was the name they were recognised by. It was only in 2006 that revision took place and gave them their current identity of C. multidentata.
If 'japonica' sounds a little Far Eastern to you, then you’re on the right track. This name refers to their Japanese heritage, where Takashi came across them and where many come from today. The original specimens were recorded from the Ogasawara (or Bonin) Islands, though they’re just as happy on mainland Japan too.
Some folks have the impression that Amano shrimp only come from Japan and its immediate vicinity, but this is far from true. In reality, Amano shrimp are also found in Taiwan, the Ryukyu Islands (between the Philippine and East China seas), Fiji and maybe even Madagascar, though this is unlikely. There was contention over the validity of the Madagascan shrimp. As far back as 1965 taxonomists (namely Dr Holthuis) have been marking them out as different and have cited features such as moving rostral teeth as adequate features that have granted them their own species status.
There’s even the strong chance that some of the Amano shrimp on offer in the trade are not true C. multidentata. Caridina make up a huge genus of approximately 280 different species spanning across Asia, Oceania and Africa — there’s even a Caridina species in Lake Victoria. With such an abundance of species, many physically very similar, it’s easy for imposters to slip under the net and enter aquaria. One shaky train of thought is that many 'Amano' shrimp on sale are not true, Japanese specimens but a Taiwanese variant.
These 'Taimanos' are identified by two features: the first being their shorter, compact rostrum, and the second being their inherent laziness. Supposedly, these false shrimp also breed entirely in freshwater, which is something that C. multidentata do not do. But aside from that they have the same, nondescript colours and similar markings.
There are even hints of an Indonesian variant doing the rounds, but these are also contested on a species level; they have a straight rostrum and not a crested one. Buyers beware, and be diligent. True Amano shrimp should be relentless workers, and that’s exactly what fuels their popularity. Tirelessly padding away with their tiny maxillipeds, they will graze on almost all forms of algae with just the dreaded Black beard algae and some cyanobacteria types being sometimes averse to their palates.
Lacking cutting or biting mouthparts, at best they can softly rasp away at surfaces taking away the topmost film. This inability to cause harm makes them ideal workers in tanks where there are small fish and even fry, which they will largely ignore. My own experiences have seen the occasional, bold Amano tootling off with a prize in the form of a fish egg, but their impacts on breeding populations are negligible at best.
Some aquascapers have griped and bickered that their Amanos have damaged planting, but this is unfair condemnation. Amano shrimp will indeed rasp away at plants but are only able to take away material that is already dead or dying. It’s not unusual to find perfectly cut holes in leaves, where plants have degraded through nutrient deficiencies and the shrimp have cleaned the site up. Much like maggots in a wound, they’ll only eat the bad and leave the healthy.
Second to none
The benefit to the aquarist in keeping these shrimp is huge. Their eating efficiency and digestive capacity is second to none, and, in part, a reaction to what can be an oligotrophic lifestyle.
In the aquarium they will pick up on almost any waste, be it uneaten food, fish faeces, decaying plants, or whatever, and convert it into tiny packages of shrimp waste, almost like large grains of jet black sand. These can then be easily siphoned from the tank during a water change.
Regardless of how good a cleaner they are, remember that Amano shrimp do not impact on nitrate levels at all. It does not matter if you have ten or two hundred of them, you’ll still need to water-change just as frequently!
There’s little reason to consider a biotope for these creatures, but if the idea appeals then simply go in for a large tank with big rocks and boulders inside it. Alternatively, Amano shrimp can be found in swamps with a handful of mossy plants and organic litter.
Don’t be scared of a little turbulence either. In their natural range, Amano shrimp are often subject to middling to strong flows and have a better grip on surfaces than you might expect.
Tolerant creatures (Picture above by George Farmer)
Amano shrimp tolerate a range of water conditions with the exception of the usual suspects that are ammonia and nitrite. Some sources cite Caridina as being indifferent to nitrite, but this isn’t always the case. Although nitrite reacts in different ways to shrimp blood as it does to fish blood (contact with the latter forms the lethal methaemoglobin), at high doses it can still cause a degree of mortality and difficulty.
As well as ammonia and nitrite, heavy metals should be avoided so remove any rocks with striated lines of metal through them and avoid lead weights for plants. Although these become issues in mainly softer, acidic water, even in hard systems they can form dangerous levels.
Aquascapers are occasionally worried about the heavy metals found in plant nutrients, but to my knowledge there is no credible evidence that even a major overdose of ferts causes health issues or fatalities in Amano shrimp.
Avoid salt, too. Though this chemical is essential for the rearing of larval shrimp, the adults have no tolerance of it and even background levels used as tonics (3g per litre) can be lethal to them. Hardness needn’t be high, but GH should not be below 6° for successful moulting. Temperatures are tolerated between 18 and 27°C/64.4°F and 80.6°F, and fluctuations between day and night largely ignored.
One area of caution is the use of CO2, especially where Amanos are in planted tanks. Excess CO2 will drive the pH down, and below 6.0pH they will struggle.
They will go up much higher and all the way to 7.5pH without problems. Above this they don’t fare as well and their lifespans will be shortened. Caridina multidentata are pretty resilient when it comes to diseases and aren’t affected by the gamut of usual fish ailments.
White spot and fin rot is not something they’ll experience. In fact, aside the problems of Planarian flatworms that sometimes fight to get under the carapaces of shrimp there are few health issues. Some commercial shrimp suffer fungal issues and many fancy types carry a small flatworm on top of their heads called Scutariella japonica, a miniature symbiont that does little except eat particles of shrimp food and lay eggs in the gills. Amano shrimp, however, seem rarely afflicted by this.
The biggest danger to your shrimp is poisoning, especially from airborne insecticides and more so from imported aquarium plants that haven’t been properly rinsed. Subjected to these chemicals, shrimp will rapidly turn from transparent to white and/or pink and lose all composure and momentum. Shortly afterwards they will be immobile on the base of the tank with only their tiny pleopods twitching, and then they will die. There is no cure for poisoning once it takes hold, so avoidance is the only sure course.
Keep them correctly and you can expect a lifespan of up to four years from your shrimp, over which time they can reach up to 5cm/2" in length.
Choosing the best filter for the job
Filtration for Amano shrimp needs to be unable to suck them in, but they also benefit from having access to sponge filter media where they will nibble at the biofilm and waste contained within. Foam, air-powered filters are a good choice, but better still is the Hamburg mat. This involves placing an entire sheet of foam within two guide rails to create a filter 'wall'. An uplift is then placed behind the mat, just like the uplift of an undergravel filter, and water pulled through the foam and back over the top into the tank.
Hamburgs provide a huge filtration surface, as well as an ongoing source of food for shrimp, and cost pennies to put together. Your local aquatic store can likely give you more advice and the parts required to put one together if you choose.
How well do your Amanos grow?
All crustaceans need to shed their shell in order to grow, and this stage is called moulting.Shrimp moult more when they are younger and, subsequently, growing faster, though adults may moult on around a monthly basis. This also helps to keep the shell healthy and free of pathogens.
With insufficient GH in the water, moulting is impaired. Some keepers rattle sabres over whether or not to leave the shell in the tank once the shrimp has shed.
In theory, the shrimp will ingest some of their own shells and regain some of the valuable chitin within. But in reality if diet is appropriate and GH levels adequate, then this will be surplus to requirements.
That said, there’s no harm in leaving the shell in the tank for grazing purposes.
Differences between prawn and shrimp
People often ask what the difference is between a prawn and a shrimp, and everyone likes to hold a pet theory about what constitutes each.
In reality there is no difference between the two words, and they are arbitrarily assigned to whatever takes the whim of the user. Scientifically the two names carry no meaning, so you should feel free to call your own tank inhabitants a troupe of Amano prawns if that’s what you prefer. So there you have it. Prawn and shrimp are common names, which vary considerably depending on where you are.
If you’re in America you might be sold prawn as shrimp, and in the UK you’ll get the reverse but it’s nothing deeper than that.
How many legs do shrimp have?
Shrimp belong to the order Decapoda, like crabs and lobsters. The common feature between them is that their ancestral progenitor had, at some stage, ten pairs of legs.
Looking at a shrimp it might appear obvious that nowadays they have anything but ten pairs, but the point still holds. They have just adapted and changed the forms and roles of their legs, so that the ten pairs are now divided up between the pereopods, or walking legs, and maxillipeds, or mouthpart legs. The swimming legs, the pleopods, at the rear end are a different matter altogether and are not classed as legs in the same sense.
Copper and crustaceans don’t mix!
Most medications come with clear warnings that they shouldn’t be used with shrimp and for good reason. Anything containing copper compounds is lethal to crustaceans and needs to be avoided.
The reason it is so dangerous is down to the blood of the shrimp. We humans use haemoglobin, which is basically iron that makes up our blood cells, to carry our oxygen around. Crustaceans, however, have blood cells made up of haemocyanin, which uses copper instead of iron to carry oxygen. When using copper-based medications this blood is affected, ruining the crustacean’s ability to ventilate.
Some keepers are reluctant to use water that has been stored in a hot water tank or run through copper piping for fear of contamination, though this only tends to be reported as an issue in new plumbing systems that have not had the chance to calcify inside. An offshoot of having copper-based blood is that unlike our own, which is red, in shrimp and other crustaceans it is blue.
Breeding antics (Picture above by ãµã†ã‘, Creative Commons)
Caridina multidentata is incredibly difficult to breed. Though the leaner males will frequently engage with the plumper, larger females, raising the larvae (sometimes called the Zoea) requires a marine and brackish stage.
Wild shrimp live coastally, where they release their young downstream into the sea. After some four to five weeks, during which the Zoea frequently moult and fatten up on plankton, they become parva, which move back upstream to restart their lives in freshwater mode. This explains their distribution over so many sea bound islands. As the females become increasingly pregnant (or berried) they will show a telltale darkening in the first segment of their abdomens.
My own Amano shrimp bred more by extreme coincidence than skill of any kind. Kept in a 120cm/47.2" cube tank with diabolically slow flow, the tank and adjoining system would be periodically treated with salt to help new arrival fish.
Also in the tank were large, adult Piranha who frequently bred. With ample surface cover in the form of dense duckweed, I would periodically tap the surface growth while holding a net underneath to frighten the Piranha fry into the net. Each and every time I did that, I would yield around 50 to 100 shrimplets for every juvenile Piranha. My only explanation is that with such slow flow and large volume my tank may have developed a slightly saline 'layer' within it, in which the young shrimp had enough salt to survive. Either that, or I had a species that wasn’t the true Caridina multidentata all along.
Other diligent breeders have had stabs at breeding Amanos, usually involving a separate larval system rigged up with seawater, with mixed success. It’s certainly possible to do, but unless you’ve got something close to lab-grade facilities, including plankton sources, then I wouldn’t hold out too much hope for you!
Don't forget that PFK is now available to download on the iPad/iPhone.
If Bruce Lee had been a fish, it would probably have been a Siamese fighter! Nathan Hill spotlights this fish from the Far East, which performs just like the martial arts icon - and shows no mercy in combat...
The Siamese fighting fish is a dual-purpose animal. Depending on its audience, it might be brightly coloured with draped fins trailing. It may be compact and squat, short fins pert and erect, drab coloured and with a head full of mean thoughts.
Both examples are of the same fish: the Far Eastern Betta splendens and one of the most contentious pets in the hobby.
Plakats, the true Thai fighters, have long histories. Indigenous Thai peoples have probably kept them for 700 years or more. Farmers, began collecting and breeding the fish they found in rice paddies but, due to increasing use of agricultural chemicals, not so many are found there today.
Official reports of fights began in the 1800s and the King of Siam — as the country was then known — licensed Betta fights as well as owning a collection himself.
By the 1840s he gifted Danish zoologist Theodor Cantor some of the fish, which Cantor named Macropodus pugnax. Later, the ichthyologist Charles Tate Regan formally described and gave it the name we know it by today — Betta splendens.
Even this reflects a fighting heritage, being named after the Ikan Bettah people of Asia who were fearless warriors.
Fans of Siamese fighters hate misinformation and are keen to dispel 'myths'. Uppermost is that fighters are fine in small, unheated or unfiltered aquaria.
The idea that Betta can thrive in tiny bodies of water emanates from breeders who keep and rear them in cups, bottles, jars or tiny bowls. There are also reports that they are occasionally found in natural pools as small as the flooded footprints of cattle.
It’s hard to believe that a footprint could become a long-term home, though not possible to rule out short-term. Betta countries of origin — Thailand, Malaysia, Vietnam and Cambodia — are subject to flash floods and dry seasons, and the fish might become stranded in pools during receding periods.
It’s also possible to imagine one attempting to cross land, bounding from one pool to another, inadvertantly stranding itself in a temporary body of water mid-way.
Undisputed is that Betta are kept in tiny tanks by professional keepers and fighters, and it’s equally impossible to deny that some of the most visually amazing fish have been produced this way. Their resilient physiology comes into play, along with that perpetually helpful labyrinth organ.
Wild fighter environments are slow flowing. Betta are not powerful swimmers, preferring to use their pectoral fins for mobility. As well as rice paddies, they inhabit ponds, marshes, floodplains, canals and even lazy rivers — but never anywhere torrential.
They live in shallows and need access to the surface. Wild Betta splendens are rarely found deeper than 50cm/20” and any more in a home tank is wasted.
Siamese fighters are obligatory air breathers once past the fry stage. If denied access to frequently gasp they will suffocate. Many fishkeeper newcomers are fazed by this activity, but it is quite natural.
Larger tanks are better and should always be well decorated. Even though fancy Betta in the UK are far removed from their origins they thrive in an environment that mimics the wilderness.
The natural range of a male is around 1m square/ /11’ square, which they prowl for passing females or rivals seeking to expand their own territories
Offer 60cm/24” or more for a male and certainly not under 45cm/18”. Depth is not essential, nor open spaces. Go for dense planting and twiggy ornamentation. Some keepers avoid sharp objects, fearing they’ll tear those delicate fins but, provided the fish isn’t battered by rampant currents, this isn’t an issue.
Any plants are suitable, but if opting for a natural biotope try regional foliage, including Leersia hexandra, Ipomoea aquatic, Ceratopteris thalictroides, Nymphaea stellata, Hydrilla verticillata, Ceratophyllum demersum, Ottelia alismoides and Salvinia cucullata.
However, any dense, bushy planting will be explored, though, come breeding time, the fish may start to disassemble softer-leafed varieties. Planting wants to be intense and the fish are often found nestled among 75% plant cover or more.
Never use tanks with mirrored backs as the fish will react violently to their own reflected image and exhaust themselves trying to reach their non-existent foe.
Placing two males together is a non-starter. Though females are feisty, males contest to the death.
Males and females can be tricky in small aquaria. Males often reject the female’s presence until ready to spawn and domestic assaults are commonplace.
Females are identified by their shorter fins, smaller bodies and smaller 'throat flap' which males flare in combat. When they first meet he may flare, while she develops a dark bar on her flank. Rival males don’t do this and respond to flaring with reciprocal flaring and attacks.
Long finned or Betta-looking fish may be seen as rivals and treated accordingly. Long-finned guppies have also been savaged by a jealous fighter.
Fancy fighters are also delicate flowers. Many other fish cannot resist those long fins and certain barbs and tetras can strip a Betta to a ragged sausage in minutes!
Don’t confuse 'fighting' fish as meaning that they can hold their own against allcomers. The faster, more agile and curious will shred a Betta and once those fins are stripped any recovery will take months — if ever.
Fighters won’t tolerate poor water quality. Though they can exist in water with low oxygen and high carbon dioxide, they don’t always thrive in polluted waters.
Just as other fish they have no defence against ammonia or nitrite poisoning, aside the lowered toxicity of ammonia often offered by their acidic environments.
Aquarium conditions should be as those for other fish, with no ammonia or nitrite and minimal nitrates. Create these with light stocking and mild flow filtration. Avoid any powerful internal or external canisters, opting instead for slow hang-on or air-driven filters.
Native water hardness varies from source to source and readings between 4-20°DH pose no problems. A pH value between 6.0-8.0 will keep all but the most fickle happy.
Temperature is open to debate. Fighters are often marketed for unheated tanks and, although they can tolerate a range of temperatures, thresholds tend to be higher than lower.
Fish kept in cooler water often have health issues relating to slow metabolism and take long to repair after physical damage. They may also develop bloat and become susceptible to pathogenic infections if kept chronically cold.
Most keepers opt for between 24-30°C/75-86°F, as there’s no definitive consensus. Fighting Plakat have been kept up to 38°C/100°F with no ill effects.
Salt is offered to keep fighters in fine fettle, but the benefits are negligible and can be detrimental over a long period. It should only be used to treat specific problems and avoided as a daily tonic.
What is a Plakat?
Plakat translates as 'biting fish'. Technically, a range of Betta species reared for fighting may be Plakat, though in this feature I’m only applying the term to short-finned Betta splendens.
Types of domestic Betta bred as pets, not fighters, are Plakat cheen. These have elegant fins, colourful scales and are less aggressive.
Shorter finned Plakat are Plakat morh, or Plakat luk morh — meaning Plakats from earthenware, pertaining to how they are kept. Having thicker scales, less colour and almost psychopathic aggression, their purpose is clear.
Betta, other than Plakat morh, also appear at bouts. Plakat pah (Plakats from jungle) usually refers to Betta imbellis. Occasionally Betta imbellis, Betta splendens and other Betta species have been crossed to make deceptively powerful but fraudulent Plakat pah. You even have Plakat thung — Plakats from flooded areas.
Fighters are bubblenesters, with the male using his adhesive saliva and pieces of vegetation to create a nest in a quiet part of the tank.
Breeding tanks should be 45 l/9.9 gal or more and plenty of hiding places for the female are sensible. Keep pH at around neutral and temperature at 25-26°C/77-79°F Bare-bottomed tanks will be easier to clean too.
The male and female will come together underneath the nest, becoming intensely coloured, and the two will interlock to form connecting horseshoe shapes. As this occurs she releases her eggs and he his sperm. Afterwards the male collects the sinking eggs and spits them into the nest.
After spawning, remove the female as the male will then turn on her to protect the brood.
Expect the first young to hatch after a couple of days.
During that time he will still look after them. Remove the male from the fry after two days, just before the young start to swim, for at that point he may be getting ready to eat them.
Rearing babies is easy with a mixture of Liquifry no.1, freshly hatched Artemia and infusoria.
Leaf litter will also help promote tiny organisms the fry will browse on as they grow.
Fighters take a wide range of foods, but are happiest grazing through small, live meals.
Colour-enhancing flakes are available, as are dedicated Betta foods, but to see these fish at their very best offer plenty of frozen and live Daphnia, Cyclops and occasionally bloodworm.
Don’t be averse to offering the occasional flaked pea to help stave off constipation and bloat, which fighters can get when fed excess dry food.
Some breeders allow the fish to eat at leisure by having live foods like Daphnia constantly in the tank. Though many fighters are not gluttonous, plenty are fussy and keeping weight on them can become an issue.
Betta can miss out in community tanks with faster fish, so ensure they always get their fill.
Siamese fighters are not long lived. Wild specimens can expect a year or two until conditions such as drought or predation take them and in the aquaria don’t expect them to reach ripe old ages.
Bear in mind that the fish sold in stores will already be around six months of age, so expect a realistic year to eighteen months from them.
There are many reports of domestic fighters reaching four or five years in the aquarium and there’s one contentious report of steroid use prolonging life to more than seven years.
A taste for almond
Plakat breeders and keepers have long recognised the merits of having almond leaves in Betta tanks. Not only do these acidify the water as they release tannins, but also have health benefits.
They contain antifungal and antibacterial chemicals for their own protection and these leach into the water where they have a mild disinfectant value.
Some chemicals are known, like the flavonoids quercetin and kaempferol. Other constituents like saponines and phytosterols are also present and almond leaf derivatives are often used as herbal medicines.
These agents aid recovery in true fighters and it’s thought that the presence of almond toughens the scales and skin to make them more durable battlers.
Are fish fights still legal anywhere?
Put two fighting fish together in the UK and you’ve violated the Animal Welfare Act, facing a fine and ban from keeping fish.
However, other countries have more vague legislation and Thailand is introducing a range of measures which would also end cock fighting there.
Restrictions on fighting fish are in place there but not from a welfare perspective, rather on volume of unregulated gambling. At the moment you can fight, but can’t put money on any outcomes.
Other Far Eastern countries have taken mixed and contradictory approaches and contests still regularly take place in Cambodia, Malaysia and Vietnam.
Genetic strains of fighting fish
Wild Betta splendens have experienced selective line tinkering and now a vast range of colours, fin and body shapes are available. These include, but are not limited to:
- Plakat – wild-type fighter.
- Halfmoon Plakat (HMPK) – short ‘D’ shaped tail.
- Crown tail Plakat – short tail but heavily spiked.
- Veil tail – long, drooping tails and most commonly seen on sale.
- Crown tail – like the Veiltail, but with extended fin rays, giving ragged effect.
- Comb tail – a crowntail with much shorter extensions.
- Spade tail – tail culminates in sharp point.
- Halfmoon – tail ‘D’ shaped, but not over 180° spread.
- Over Halfmoon –short tail spreading more than the 180° ‘D’ of a standard Halfmoon.
- Delta tail – tail with less spread than a Halfmoon, with sharp edging.
- Halfsun – Halfmoon tail with slight crowning.
- Double tail – tail split so that top and bottom halves appear distinct.
- Rose tail – overgrown tail which appears ruffled and rose-like.
- Dumbo –variant with hugely enlarged pectoral fins, like elephant ears (pictured above).
New crosses and finnages are constantly being developed and it’s not unusual to encounter a mixture of shapes and strains.
The making of a champion
In Thailand there’s more to fighting Plakat than just putting two together and (illegally) placing bets. There are distinct fighting characteristics as well as different Plakat forms.
Considerations include family, using phrases like ‘harsh’ or ‘crazy’ to describe its background. There’s bloodline or origin and age, though colour is less of a factor.
Fish will be categorised by fighting style, using terms like ‘strong mouth’, ‘chase’, ‘force bite’, and ‘good skin’. Fighting focus is recorded as ‘face’, ‘fins’, ‘stomach’, ‘ear’ and so on. Even teeth types and stamina are taken in to account.
Good history fish command high prices and figures of US $65/£42.50 or more per fish are not unknown.
Four forms of Plakat body shape are usually recognised.
There are snake-fish head/long bodies (Plachon) noted as fast, aggressive and with sharp bites; short head/short body types (Plamor) considered slower, but tough; sharp curve mouth/long body types (Plakrai) being very fast with strong bites and the hybrid (Plasang) which is often a smaller blend of wild and line-bred fish.
There are also noted styles of combat and techniques include double hits, turn-back hits and even persistent hits.
If a fish loses a bout but survives, he may be released back into the wild, or, if he showed potential, used for breeding. He may be retired and kept as a pet, or even end up in a water tank to help keep nuisance mosquito and midge larvae in check.
Don't forget that PFK is now available to download on the iPad/iPhone.
Nathan Hill reveals a fish more feared for its hunting prowess above water than in it.
For many, the Silver arowana is the definitive big fish. Related to mighty Arapaima, this fish is not only coveted but in some cases culturally revered — or at least its Asiatic cousins are.
Visually, there’s little mistaking an American arowana for anything else. Having gigantic scales, stylish wispy beards and powerful, sleek body, they look unlike anything else that roams the waters.
South America is home to two species; the Silver arowana (Osteoglossum bicirrhosum) and the lesser-seen Black arowana (Osteoglossum ferreirai).
In juveniles, the differences are quite apparent; one silvery sheened, the other with clearly blackened flanks. In adult form, though there are noted differences in body colour, the most prominent contrasts being in the fins — the Black arowana having considerably darker dorsal, anal and caudal fins, with red and yellow outlines to them on show.
Silver arowana are endemic to South America, in the Amazon basin through French Guiana, Peru and Brazil, and it’s speculated that they haven’t become more widespread only because they can’t navigate rapids and torrential flows.
In the wild, these are spectacular hunters, though at the top of their game above the waterline rather than under it. Their ability to launch from the water has the locals calling them 'water monkeys' — and leaping is something at which they excel.
Reaching for insects
This behaviour is a response to life in the flooded forests where they are common. Here, limited food resources are dispersed over vast areas and niches must be found to exploit what there is.
They are also found hunting along shorelines, inhabiting blackwater lagoons, as well as the littoral zones of rivers and lakes. They are always in shallower areas of water too where the depths offer no benefits.
They launch to snatch at terrestrial insects, but they’re not particularly fussy. Spiders form a large part of the diet, as do beetles, which may be their preference if gut analyses are indicative. Small birds have been eaten, even snakes hanging from overhangs. Other less usual snacks can include crabs, snails and even monkey droppings.
When they leap they often get a side salad of the vegetation the prey had sat on, though it’s not considered essential to offer them green food supplements.
In the aquarium, this propensity to feed from above the waterline is not catered for by all that many aquarists. Instead it’s expected that the fish will take a variety of dried, fresh and frozen foods below the water surface.
Unfortunately this damages the fish and results in a condition called ‘drop eye’ whereby one or both eyes permanently look down, eventually refusing to return to normal. It’s a direct result of adapting to feed from meals on the base of aquaria.
Foreign keepers who use live fish to feed their arowana report the same symptom.
Always try to offer a floating food or train your fish to take from the surface alone. That means interacting and getting involved at every mealtime to get your fish accustomed to feeding from specific points in the tank — and offering a little at a time so food does not sink past.
'Drop eye' also seems more prevalent when these fish are kept alongside other species that swim beneath them.
Some speculate that arowana have superb eyesight and can make compensating calculations for refraction prior to leaping. However, it seems likelier that the reason for the monstrous maw is a morphological offset to compensate for rubbish vision!
Arowana in the wild often take surprisingly small meals per leap, and mouth size may compensate for terrible aim, or at least increase chances of snatching food.
Just because they have an almighty opening they do not necessarily need gigantic meals. Even for adults, crickets and locusts, earthworms, prawns, mussels, cockles and chunks of fish are more than ample.
Striking above or below water affects posture. When priming for an airborne launch they form a spectacular, anguine ‘S’ shape before take-off, though if underwater will often opt for a ‘C’ shaped curve.
Wild fish have been noted to hide behind fallen trees when in hunting mode, curled and waiting…
That gigantic mouth is also used for spawning. American arowana are mouthbrooders, with the male carrying the young a good two months until their yolk sacs are depleted. Often both wild and farmed fish are harvested at this stage, with adult males being frightened or coerced into dropping their young into the nets of collectors and then traded.
Don’t buy an arowana while it still has its yolk sac, as at this stage it will not yet be feeding. Moving yolked juveniles is irresponsible as, if ruptured in transit, the fish is almost certainly doomed.
Spawning arowana form pairs while young, though trying to pair them off in an aquarium is rather futile. Dedicated breeders use huge concrete or clay pools and a massive area is required for success.
Given the high commercial value of exporting arowana, there have been numerous disputes and accusations involving wild harvesters — giant otters once being blamed for reducing stocks, although evidence was lacking.
Given that arowana spawn only once a year, it’s now considered likely that excess harvesting is impacting on populations.
The drawback in keeping these fish is their size. Even aquarium specimens attain around 90cm/36”, and wild fish can be larger still.
Some sources cite a 240 x 90 x 90cm/95 x 35 x 35” tank as sufficient for a single adult, but not everyone would agree. Based on the ‘six times’ rule a 6m/20’ tank is required, which eliminates nearly every private aquarist, aside those with tropical ponds.
Essential if keeping arowana is a well fitting, jump-proof hood. If left open topped they will leap. They just can’t help themselves!
Also be wary for your own safety. That giant, toothy mouth and urge to fly at anything slightly food shaped means that the aquarist can soon become the snack if any food is inappropriately offered via the fingertips.
If wanting to see that jumping behaviour you’ll need long tongs or some kind of feeding stick.
Setting up a tank, aside the size issue, is easy. In a nutshell arowana are not fussed what’s going on beneath them, so décor is redundant. For authenticity opt for plenty of fallen branches, leaf litter and fine sands, but also be aware these big fish also produce lots of waste and frequent water changes, and waste syphoning is essential.
There’s good reason so many Far Eastern keepers opt to house theirs in barren tanks devoid of any décor.
As appealing as these are, don’t be inclined to buy a juvenile unless certain you can provide for it. Young fish are visually more pleasing than adults and it’s easy to get suckered in. Yet later you may struggle to find anyone sympathetic to requests for rehoming and you’ll be lumbered with a fish that may be bigger and more demanding than a small dog.
Scientific name: Osteoglossum bicirrhosum
Maximum size: 90cm/35” aquarium, 120cm/47” wild.
Feeding: Slight omnivore with heavy carnivore leanings. Fish, prawns, mussel, cockle, all insect matter, crab, squid, even some lean terrestrial meats will be taken.
Water chemistry: Acidic water, pH ranging from 5.8 to 7.0, hardness below 14°DH.
Compatibility: It can be kept with other fish too large to be eaten, though this may increase incidence of 'drop eye'.
Distribution: Black and white water floodplains of Brazil, Peru, French Guiana. Introduced elsewhere by humans.
Breeding: Not known in aquaria.
Difficulty level: Juveniles easy, adults extremely hard.
Scientific name: Osteoglossum ferreirai
Maximum size: 90cm/35” aquarium, 90cm+/ 35’+ wild
Feeding: Slight omnivore with carnivore leanings and eats the same as Silver arowana. Wild specimens have even been reported with remains of small monkeys in among gut content
Water chemistry: Acidic water, pH 5.8 to 7.0. Hardness below 15°DH
Captivity: Keep this with fish too large to be eaten, though tank mates may be linked to 'drop eye.'
Distribution: Negro river basin.
Difficulty level: Juveniles easy, adults extremely hard.
Noting the arowana’s large scales, huge mouth and dragon-like appearance, Far Eastern culture associates this fish with money and wealth.
In Chinese culture fish are indicative of abundance, while dragons are associated with wealth and prosperity.
The arowana’s ability to combine the two features in one handy package makes them highly desirable to keep.
Asian varieties are so highly prized that they are even anecdotally connected to some Triad gangs and gangsters.
Post-natal booster food
Arowana make for excellent eating, given their low fat, high protein nature. The Caboclo people of the Amazon feed them to women who have recently given birth, so highly regarded is the fish’s nutritional value.
See some of the other articles in this series:
Don't forget that PFK is now available to download on the iPad/iPhone.
When Jeremy Gay persuaded a PFK photographer to finally upgrade his reef tank, it was with the proviso that he helped out with the new one.
If there was one bit of advice I could offer to any reef tank owner, I would say be patient. PFK’s resident photographer Neil Hepworth first got into marines nearly ten years ago, and in that time he has continually run just the one tank.
I helped Neil out with his first tank too, because when he took up reefkeeping he had not kept fish before. It was a 1.2m/4' tank with a wooden cabinet and hood, and I specced it out with a combination of spare electrical goods and purchased products. The tank wasn’t drilled to connect up to a sump, and back then it was an issue just finding a protein skimmer that would fit on such a tank with both a box hood and glass bracing bars.
The initial set-up ran as a basic Berlin system with lots of good quality live rock, powerheads, fluorescent lighting and a protein skimmer. My initial advice was to have just soft corals but within a few years that same tank was home to both LPS and SPS corals. This was achieved without a calcium reactor or supplements, but thanks to Neil’s diligence to water changes and maintenance.
Make no mistake though, that set-up was not without its problems. There were several large wipe outs of corals and fish, many still unexplained to this day, and years of salt spray from the skimmer meant that much of the back of the wooden hood eventually disintegrated.
So, nearly ten years and two house moves later, we were out on a Shoptour, steered cleverly by me to include a tank manufacturer, and Neil eventually agreed to buy a new tank.
Time for a change
Tank fashions have changed quite a bit in ten years, and this time Neil wanted to change the smooth woodgrain of his polished aquarium for the clean lines of a modern-looking gloss white cabinet. I tried to get him to buy a rimless, open-topped aquarium like the one I was planning for myself, but Neil opted for an open-topped pelmet instead. I quizzed the tank builders as to options for the pelmet, because if you make it too high the tank can look top heavy, clumsy and even dated.
We got the pelmet height down to 100mm instead of the usual 150mm or more, and for the cabinet design itself we opted for minimalist design with push open doors, no handles and a very clean, Japanese style.
Marine equipment can look very daunting and nothing is more scary to the inexperienced fishkeeper than a sump tank. It took me years to convince Neil that sumps were better for reef tanks and that, if you do it right, they don’t flood. He wasn’t so sure, but I gave him my guarantee that I would design and build his new tank as if it were my own and that I would run him through what happens in a powercut when we set the tank up. He eventually agreed.
The cabinet was 120 x 75 x 60cm/47.2 x 29.5 x 23.6” so had lots of room for a sump, and I made sure that three large holes were drilled in the back for ventilation. The sump, I told the builder, I wanted to be 91.4 x 45.7 x 45.7cm/3’ x 18” x 18” with three chambers: one 30.4cm/12” chamber to house a nice big protein skimmer, one 45.7cm/18” chamber after that to act as an algae refugium and deep sand bed, and a 15.2cm/6” chamber after that for return pump.
The cabinet and sump were also large enough to include a calcium reactor, phosphate reactor or pellet reactor and an automatic top-up, but Neil felt that the sump and refugium were about as far an evolutionary step as he wanted to take — for now anyway!
I’d played about with quite a few sumps and weirs by the time I helped Neil out with his, so I was pretty clear on what I wanted: a corner weir, ideally square or rectangular, in black, with both top and bottom scavenging weirs to drag water from the surface and from the substrate at the same time.
I also wanted three holes drilled in the base of the corner weir — one for an outlet pipe, one for an inlet pipe and a spare outlet pipe to prevent accidental flooding. I also specified that I wanted room to make one into a 'durso' using 90 degree elbows, and if you ever want to, you could even ask for a fourth hole and pipework to run the pump’s power cables down into the cabinet from the main display tank. The tank builder said they did triangular not rectangular weirs, but they could do everything else I requested.
We could have ordered the bulkheads and pipework from elsewhere, but with there being both metric and imperial pipe fittings and hole cutters out there, one way of ensuring that the manufacturer would drill the right size holes was to get him to supply the fittings too.
One of the most frequently asked questions of the PFK team is how to move tanks. This was Neil’s predicament too, only there was lots of space around it. The tanks were positioned next to each other for the changeover. I supplied lots of empty RO drums, we siphoned as much tankwater as we could in a short time, briefly exposing both rock and corals, and then pushed the old tank out of the way.
Thanks to Neil’s oak floor we just about managed to get some carpet under the cabinet to make sliding it easier, and within five minutes we had turned off, siphoned, slid, filled up and turned back on again, and both fish and corals were none the worse for the experience. That bought us infinite amounts of time to put the new tank in its place and plumb-in and glue the pipe fittings.
My plan was to do the whole changeover within the space of a day. The original tank had a gross volume of about 200 l/43.9 gal, yet the new tank and sump held over 500 l/ 109.9 gal. Neil had an RO unit so I advised him to collect at least 12 drums worth of pure RO before putting it into the pond tub that I lent him, with heaters, circulation pump and airstone to mix up 300 l/ 65.9 gal of salt.
Once mixed he could then pump the saltwater into the 12 drums (hired from an aquatic shop), store them inside the house in the warm and then he would be ready to go on the day of the changeover.
We also made sure we had plenty of buckets, towels, siphon tubes, a new larger heater, a plastic tub to put all the rock and corals into and that no one else would be in the house, or in the way, on that day. I advised Neil to cut feeding down in the days up to the move and for a few days afterwards to cut down waste produced.
With the sump plumbed in and the pipe cement cured in the new tank, it was time to move everything over. My plan was to make the move as seamless as possible by moving all the rock, all the substrate and as much of the water from the old tank as we could.
We placed a black plastic Laguna pond tub on the living room floor and proceeded to move what live rock pieces we could into it. As the water got deeper in the tub, the corals could go in and then the rest of the rock, leaving the old tank clear of décor so we could catch the fish. The fish went into the tub too, along with the old powerheads and heater. Although not lit, this tub would now be perfectly biologically stable for as long as we needed it to be.
The old tank substrate I opted to put into the new tank sump was part sand bed and part biological starter colony. This would move many critters over as well as beneficial bacteria.
The old tank had the now dated rock-wall look, with all the rock being stacked up against the back. From what he had seen in some of the tanks he had photographed, Neil wanted some central rock bommies, which I was more than happy to help with.
I would use acrylic rods to thread the rock onto. Self-supporting narrow bommies mean better water circulation than rock walls and with less detritus build-up or dead spots. We bought some acrylic rods from a reef store, a masonry drill bit with a slightly larger diameter than the rods and in no time had created a bommie stretching the full height of the 60.9cm/24” tall tank.
We then poured all of the new saltwater into the new tank, topped up with enough old saltwater to fill the sump and get the system going, plugged in the new heater and return pump, checked the water and when it was it was up to temperature, moved over the fish and corals.
Yes the water was cloudy, as you might expect, but corals can deal with this and fish and corals were all fine when the water cleared the next day. The old tank was emptied, taken outside and the job done before Neil’s partner got home from work. I got Neil to buy some Spaghetti algae, Chaetomorpha spp, to place into the new sump chamber on the day of changeover. This I advised should be lit 24/7.
Again we built up the new equipment over time, buying from wherever we could. Neil’s always felt a bit guilty about keeping marines so wanted some eco-credentials. I told him LED lighting would be a no brainer and fitted the tank with two TMC Aquaray LED tiles to light each of the bommies and four TMC Aquaray LED strips to provide additional light if needed. The effect is dramatic and striking, and the lack of light spill from the LEDs and the central bommies mean that you get a nice blue infinity effect from behind, aiding the feel of depth in the tank.
The lighting rig also means that Neil isn’t getting heat issues like he did with the old tank; they’re silent because they don’t use fans, they use less energy than his previous lights on a smaller tank, and their slim profiles mean that they don’t protrude past the outer line of the slim, open topped pelmet so the whole build looks really modern and clean.
Neil moved the circulation pumps across from the old tank, but within a few weeks it was obvious that they weren’t moving the water enough. On my advice, and after a talk-through the features, Neil replaced the pumps with two VorTech MP40esW from EcoTech Marine.
Despite forking out a few thousand pounds on the new set-up in all, Neil loves his new tank. With its design and build, the simple methodology it’s running, plus the new lights and pumps, we managed to come up with a reef tank that will last another ten years and has bags of potential.
Being a keen gardener, Neil likes to buy small coral frags and nurture them over time, and the more spacious aquarium and its open aquascape will allow the corals to grow pretty big, without coming up against the confines of the tank walls. As the corals grow and increase in number the aquascape will look a lot better.
Would I have done anything differently in hindsight? Well, Neil doesn’t mind but that triangular corner weir is quite large, a little too large for my tastes. I’ve since bought and long-term tested the discrete Xinout pipe fittings from Italian company X-Aqua on my own tank; they do away with the need for a weir. For the price though, and considering the Xinout’s limited scavenging capabilities, I would still consider a nice black, rectangular corner weir for future projects, and I do still like my rimless tanks with nice chunky Optiwhite glass throughout.
I did set-up such a modern reef tank for myself not long after Neil’s, using the Zeovit method and I really liked it. So, if I had Neil’s tank now I’d run the full Zeovit, Zeolite and bacteria method with an automatic top-up, which is something I wouldn’t be without on any marine tank.
And finally, because the tank is in a lovely large dining room, there’s plenty of space to have opted for a 244 x 60.9 x 60.9cm/8 x 2 x 2’ tank, instead of the 121.9 x 60.9 x 60.9cm/4 x 2 x 2’!
Tank size: 121.9 x 60.9 x 60.9cm/4 x 2 x 2' custom-built tank, sump and cabinet from Aquariums Ltd, which is no longer trading.
Sump: 91.4 x 45.7 x 45.7cm/3' x 18" x 18" with room for protein skimmer and algae refugium.
Lighting: 2 x AquaBeam 1000 Ultra Reef White and 4 x AquaBeam 500 LED strips on MMS mounting system.
Protein skimmer: Hydor Performer skimmer.
Return pump: Tunze Silence 1073.020.
Circulation pumps: 2 x VorTech MP40esW.
Filtration method: Berlin hybrid — live rock, protein skimmer and algae refugium.
Live rock: 30 kilos.
Chemical filtration: API Bio Chem Zorb (carbon) and Rowaphos phosphate remover.
How we created our reef tank step-by-step
1. Polystyrene goes down under the tank and the bulkhead fittings are connected and sealed with silicone.
2. Standpipes are in place, complete with Durso overflow method to reduce noise.
3. The sump is placed inside the cabinet, again on a layer of polystyrene to cushion it.
4. Ball valve and pipework are fitted under the tank. The ball valve reduces noise.
5. Existing live rock, fish and corals are placed in a black tub so that the old tank can be emptied and removed.
6. New bommie formation is created by threading rock onto an acrylic rod.
7. The bommie is lifted onto the rod and placed into the new tank, which is being filled at the same time.
8. Chaetomorpha algae is placed into the algae refugium, along with some small live rock pieces and the old sand substrate.
9. A TMC GroBeam tile is fitted over the algae refugium in the sump, again using a rail system for support.
10. The tank is filled and fish and corals are moved over. The water is cloudy but parameters are stable and match the old tank.
11. The next day the tank is clear and the fish and corals start to make an appearance.
Don't forget that PFK is now available to download on the iPad/iPhone.
Gobies can be found in almost all bodies of water, including the coldest oceans to freshwater mountain streams. And there are plenty of marine gobies that are perfect for the reef aquarium, as Dave Wolfenden explains.
Some gobies are so incredibly adaptable that they have even evolved to exploit a partly terrestrial lifestyle in the shape of the endearing mudskippers.
They are all part of the Gobiidae, one of the largest of all fish families, and there’s even a considerable choice for marine aquaria. Despite their small size, these fish can have bags of personality, usually making them excellent reef choices.
Because of their size, gobies should not be kept in the aggressive fish-only system as they will be harassed by many larger species and many predators will snack on them. However, most will be superb for the reef aquarium, providing any chosen tank mates are peaceful.
Certain gobies, though, can be intolerant of conspecifics or even heterospecifics that look similar, especially in limited space.
This is the result of often strong territorial behaviours tying individuals to small patches of home reef. Limit stocking to one goby of each genus unless there’s plenty of room.
Most will adapt well to captive diets and a variety of small fresh, frozen and artificial feeds is important. Many will fend for themselves in a mature reef system with natural plankton populations. Sleeper gobies, for instance, will process the aquarium’s substrate to extract the invertebrate life.
While gobies can find a reasonable amount of food in a typical aquarium, some supplementary feeding will prevent individuals becoming emaciated. Gobies in general fare best in well-established systems and a refugium can help to provide supplementary live food.
Gobies are generally sensitive to medications, because of their scale-less skin.
They’re not the most parasite-prone fish, thanks to their thick mucous coat which helps trap pathogens, but they can nevertheless still suffer from parasitic and other diseases.
Be cautious when treating for ailments. Prophylactic care for newly-acquired specimens is ill advised. Instead, try plenty of TLC and optimal water quality, plus plenty of food. If medication is necessary, don’t overdose.
When selecting specimens, avoid any looking emaciated. These may have been starved for some time and are too thin to recover.
Which species of goby is right for you?
Some of the most commonly encountered gobies in the marine hobby include Sleeper gobies (Valenciennea) which are prodigious sifters of sandy substrate, hence the alternative name of sifter gobies.
These spend much of their time ingesting sand and extracting tiny invertebrates. For this reason, they can be used as efficient cleaner crew as their constant turning of the substrate helps to maintain the sand bed.
Ensure rockwork is securely placed, as meandering gobies can easily topple piles of live rock.
Bear in mind too that they may frequently spit mouthfuls of sand over corals and other invertebrates, so strategic coral placement must be a consideration.
Blue-cheeked sifters (V. strigata) — pictured above — are often imported from the Indo-Pacific. Specimens grow to around 15cm/6” in the aquarium and earn their common name from electric blue markings on a yellow face.
Also noteworthy is the Chalk goby (V. sexguttata), again from the Indo-Pacific and reaching a similar length.
The Jam sandwich goby (V. helsdingenii) from the Indo-West Pacific, with its alternate black and white bands, looks particularly striking and again is a very attractive reef addition.
This species will reach 15cm/6” and it’s worth trying to establish pairs, as males are identifiable courtesy of their elongated dorsal fin filament.
Neon gobies are the alternative cleaners (picture above by Nick Hobgood, Creative Commons)
Several species are known collectively as 'neon gobies' and belong to the Elacatinus genus – formerly Gobiosoma. Most hail from the Caribbean and other regions of the western Atlantic.
Most commonly offered are the ‘true’ Neon goby (E. oceanops) or the Sharknose goby (E. evelynae) and both grow up 5cm/2”.
Other species may be encountered, although identification can be difficult.
These fish make a viable alternative to cleaner wrasses of the Labroides genus. They adapt well to captive diets, although will supplement diet by performing useful cleaning of 'clients'.
They will set up cleaning stations, but can defend these against other cleaner gobies — so ensure ample room if attempting to keep more than one.
Several genera of gobies form a mutualistic partnership with shrimps — notably Pistol shrimps of the Alpheus genus.
Several genera form such symbioses with shrimps, including Stonogobiops, Ctenogobiops, Cryptocentrus and Amblyeleotris. The basis of this relationship is that the shrimp are good at building burrows but have poor eyesight. The gobies have good vision and are given lodgings in the shrimp’s burrows in return for acting as reliable lookouts.
A shrimp will keep in constant contact with the goby via its antennae and both shrimp and goby retreat to the burrow at the first sign of danger.
If attempting to recreate this relationship, provide a deep substrate of varied material, from fine sand through coarse coral chips to live rock rubble. The best shrimp with which to attempt such a pairing is Randall’s shrimp (Alpheus randalli) — identifiable courtesy of its red-banded legs.
More gobies worth seeking out include the Yasha (Stonogobiops yasha) from the Western Pacific, which grows to 5cm/2”. This is very attractive but pricey.
Also check out the Dracula goby (S. dracula) from the Indo-Pacific, which grows to 7cm/2.8” and sports red and orange bands.
From the Amblyeleotris genus there’s A. aurora (above). The Aurora goby, from the Indian Ocean, grows to 10cm/4” and is stunning with orange bands. A. randalli, up to 12cm/4.7” and from the Western Pacific, has a gorgeous sail-like dorsal fin.
The cool customer
The Catalina goby (Lythrypnus dalli) is sometimes offered — and it sure has that grab factor!
Note that striking range body punctuated with bright blue vertical markings, as pictured here.
However, this species, which grows to 6cm/2.4”, is really sub-tropical from the Gulf of California and surrounding regions. As such it fares best in temperatures slightly below those in a typical reef aquarium, requiring around 18-21°C/64-70°F.
It is possible to maintain, although it requires a dedicated aquarium decorated with coarse sand and rubble, and capable of providing the cooler conditions this fish needs.
As such, this fish should not be purchased as an addition to an existing tropical reef aquarium.
Amblygobius: lovers of midwater
This genus contains a few occasionally imported species and they tend to spend much of their time in mid-water — in contrast to others of the family.
One of the most challenging of the genus is the Court jester (A. rainfordi) — pictured above — from the Indo-Pacific. Growing to around 5cm/2”. This diminutive fish requires copious amounts of filamentous algae, which is lacking in many reef aquarium systems.
Hector’s goby (A. hectori), which is also sometimes referred to as the Gold court jester and from the Indo-West Pacific, assumes strikingly similar markings, albeit with different coloration, and its husbandry needs are comparable to the Court jester
The Banded goby (A. phalaena) is less challenging to look after. From the Pacific, this species reaches 12cm/4.7” and looks stout and chunky, and occurs in various colour morphs.
Banded gobies, as a group, will spend a considerable amount of their time sifting through the substrate for food and will be therefore less reliant on filamentous algae than certain other members of the genus.
Gobiodon gobies get a grip
Members of this genus can usually be found perched on branches of stony corals such as Acropora. Being highly benthic, their ventral fins are often modified into suckers, allowing them to adhere to their host coral, even in some pretty strong surges of water.
These timid fish need to be provided with very small foods, but they can be among the most endearing and best value fish you’ll keep. They’re ideal for smaller SPS-dominated systems.
Particularly engaging is the Okinawa or Yellow goby (G. okinawae) — pictured above — from the Western Pacific. It grows to 3cm/1.2” and sports a white patch on its cheek — the only marking on an otherwise entirely yellow body.
This species appears to be an obligate dweller of Acropora in the wild and the best captive system would also incorporate such corals.
Once an individual is established in the aquarium it will perch on its coral, seemingly demanding all your attention and becoming a true and affectionate pet.
Also noteworthy are the Citron goby (G. citrinus) from the Indo-West Pacific. It grows to 6cm/2.4” and has a distinctive yellow coloration.
There’s also the stunning Green clown goby (G. histrio). This is a striking fish, with red markings on a vivid green body, but reaches only 3.5cm/1.4”. It also originates from the Indo-West Pacific.
Can I breed gobies?
Plenty of marine goby species will spawn in the aquarium if pairs can be established, but many of them are aggressive towards conspecifics.
Many can change sex too, making the establishment of pairs no problem for individuals living in the wild – as every member of the species is a potential partner!
The coral gobies (Gobiodon spp.), for example, appear to be bidirectional protogynous hermaphrodites — starting out as females but can undergo a sex change if necessary.
However, such gender bending is reversible and males may turn back into females if required.
The main challenge with breeding arises from an ability to successfully rear the tiny larvae, which need first feedings of rotifers, followed by enriched Artemia nauplii.
Gobies, however, can be a good bet if planning on a first breeding project for marines. Neon gobies (Elacatinus spp.) are probably the best prospect, as they will spawn in even small tanks if conditioned with varied regular feeds.
PVC pipes will provide a suitable love nest and the resultant larvae should be moved to rearing tanks with identical water chemistry to their original system.
Don't forget that PFK is now available to download on the iPad/iPhone.
Is there such a thing as the perfect community cichlid? Nathan Hill profiles a real stunner that certainly comes close.
Cichlids often come with a cost. Some beauties become giants, while others carry psychotic degrees of rage. Some like their water softer than marshmallow and others harder than granite. They are a fickle crowd.
One small group of African cichlids sits somewhere close to a perfect balance. As well as being quite small, their aggression only flares when their offspring are confronted by offending mouths.
They have sublime colours; so much so that their common names reflect this.
They don’t pick on their females, feed willingly, and, if provided with a little privacy, will quite happily go and spawn. And once they have, they’re happy to raise the fry up themselves. These are the Kribensis — fish that have become an aquarium standard for the community keeper.
Technically, the original Kribensis was a single species —Pelvicachromis taeniatus — which was originally misdescribed as Pelmatochromis kribensis (which also managed to gobble up what is now Pelvicachromis pulcher in the confusion) and later revised.
But, just to really confuse things, many aquarists choose to use 'Kribensis' as a colloquial catchall to refer to any of the seven species of Pelvicachromis. For the majority, P. pulcher is the 'standard' Krib and I use that association here.
P. pulcher is an aquarist’s dream. It carries the most startling colours — alternative names are the Palette cichlid, or the Rainbow krib — and it has the pointed trailing fins that one would expect from a far more expensive species. If I had to design the perfect domestic fish from scratch, it’d likely be a Krib.
The only possible drawback to these fish is their innate shyness. Kribs are not especially bold, though there are rare exceptions. To see them at their best, the inclusion of dither fish will be needed — more on them later.
All Pelvicachromis species prefer riverine conditions and are restricted to the African continent: chiefly West and West Central Africa. Only in the rarest of cases do they make an appearance in some slower moving or static flooded area.
P. pulcher inhabits a range from Benin, into Nigeria and Cameroon, and always in similar habitats.
There’s a myth that to this day keeps doing the rounds, unsupported by sound referencing, that Kribensis are found in brackish waters. In reality they cover a vast delta that stretches from around 150km inland to the sea, but repeated surveys have shown that Pelvicachromis are only found in the fresh, usually soft waters, and never in brackish conditions.
The idea of the brackish Krib seems to have arisen many years ago, possibly started by Baensch in his aquarium atlas, but has not been subsequently corrected.
To put the record straight, every bit of quantifiable evidence points strongly at Kribs being obligatory freshwater inhabitants that are quite unsuitable for life in a brackish system.
In studies of their range, the number of collectable P. pulcher substantially drops off as researchers come progressively closer to brackish water regions.
So these fish are not big fans of salt, then.
'Frynapping' (Picture of juvenile above by Tino Strauss, Creative Commons)
Changing sizes of Kribs are found at different points of rivers. The shallowest regions are home to the smallest as well as large numbers of females. Where in most areas a one male to one female ratio is maintained, in shallow regions this tilts hugely in favour of females and 1:2 is the norm. This is most likely a response to predation issues because natural eaters of the Krib — Lates, Hepsetus and Hydrocynus, for example — avoid such shallows. For a young or female Krib, there is safety in a few inches of water.
To further decrease risks, especially those presented to their own offspring, Kribs are known to 'frynap' each other’s offspring or rather to take on board clusters of fry from other breeding pairs. It is suspected that increasing numbers in a brood dilutes the risk of losing one’s own fry to a predator attack.
The fluviatile habitats of Kribs are quite fast moving, with water rushing past at somewhere between 10-50cm/3.9" -19.7" per second. That’s hardly a gushing torrent as you’d find in whitewater areas but a lot livelier than you’ll find in the majority of aquaria.
Such a flow affects the environment that the fish live in, so in this case the presence of fine leaf litter or mulm, which is where Kribs live, is sometimes reduced. Instead, riverbanks tend to be teeming with plant life, and the only debris found is large and heavy with smaller pieces being washed away.
Rounded stones and heavy branches are what a wild P. pulcher would recognise in its habitat, along with a clutter-free substrate of fine and coarse sand, and occasional larger leaves.
There are very few wild P. pulcher in the hobby, and equally scarce are wild specimens of the other Pelvicachromis species, though they do arise. The reasons for this are simple — their origins are dangerous places where the risk of murder or kidnap, particularly the kidnap of a wealthy fish scientist or merchant, is great. Boko Haram kidnappings of western workers are frequent.
To our benefit, the fish breed quickly and prolifically enough for the hobby to be supplied exclusively by tank produced and farmed individuals.
To our loss, we run risks of inbreeding and miss out on huge amounts of potential information about their wild nature.
For example, we know of many colour variations in males of any species of Pelvicachromis, and several populations of each species appear to exist in different regions. It’s not uncommon to see Pelvicachromis species offered with names hinting to their tribe and provenance. One might see P. taeniatus 'Nyete' or 'Moliwe' which will differ substantially to P. taeniatus 'Niger red'.
There are various communities and forums dedicated to the identification and breeding of these variants, and if interested I’d encourage you to investigate because there’s more to it than I could hope to even give an overview of here.
The Krib’s crib
Setting up a tank for Kribensis is easy. Whether you want to slip them into a community or go for something more biotope-based, you only need worry about water parameters for these fish to fit right in.
Plan for a tank of no less than 90cm/36" long. If going for a single pair, 60cm/24" should be
the smallest you use. Though Kribs don’t get huge, they’ll be grateful for extra space.
If planning on biotope, then sand, branches and cobbles are the prime choice of décor. For planting, provide opulent growth. Tangles of Crinum species and banks of Cyperus, Ceratophyllum and Ceratopteris, plus ample Anubias and Bolbitis fastened to the wood will provide abundant cover.
For authentic fish, think of Brycinus longipinnis tetra, and Pareutropius buffei catfish (above). Aphyosemion gulare killifish are abundant in the same areas as P. pulcher and make a pleasing enough companion.
The water for wild Kribs needs to be neutral to slightly acidic with a pH value of between 5.6 and 7.0 and a hardness as low as 2-3°KH. Temperature should be somewhere between 24-27°C/75-80°F for daily maintenance.
However, that’s wild Kribs and the farmed counterparts are considerably more tolerant of a much wider range of conditions.
In the community tank aim for water that is neutral pH, of hardness up to 7°KH, and has a temperature of about 25- 26°C/77-79°F.
Avoid housing community Kribs with other cichlids that may not share the laid-back approach to life. Fish like Blue acara or Jewel cichlids are likely to pick a fight with a Krib and should be avoided.
Likewise, catfish careening about the base of the tank and ousting Kribs from their homes will not be appreciated. House them alongside smaller, peaceful fishes with similar water tolerances for best effect.
One feature that is an absolute must for the Krib tank is the cave. Kribs love to have a home of their own in which they will eventually pair and spawn. This can take the form of an old terracotta flowerpot, a hollowed coconut shell, a custom designed catfish cave, or even a length of large bore hosing.
Whatever you opt for, ensure the Krib has a safe retreat to which it can return at any time. Bare, open tanks will always lead to disaster.
One thing that everyone needs to have a stab at is breeding Kribensis. Few fish display such a vibrant spawning dress, and it is rare for a pair to be so aggressive that either partner is wounded.
Sexing P. pulcher is child’s play, and in the exceptional, rare circumstance that your supplier can’t do it for you then you can step in and easily do it yourself.
In adult Kribensis, the male (pictured above) is always the larger of the pair, reaching up to a maximum of 12cm/4.8". Clear indications of his sex are the design of his tail, which will be slightly diamond shaped. His dorsal and anal fins will be trailing and pointed at the tips. Some keepers like to base sex on the presence of ocelli (eye spots) in the dorsal and caudal fins, but this is not reliable.
Females can display these frequently; even more so with farmed variants.
The male will sometimes have a pronounced red throat, starting at the chin and moving right down over the belly.
Females (pictured above by Tino Strauss, Creative Commons) are always smaller, up to 8cm/3.1" or so, and squat by comparison. They lack the male’s torpedo shape. As long as they’re not stressed they’ll exhibit brighter colours than males too, though note that in the female it is only ever the belly that becomes red and not so much the throat.
The female’s fins are also indicative — her having a rounded, spade shaped tail and rounded dorsal and anal fin tips.
Breeding takes place on the inside roof of a cave after a dance and display during which the female forms a vague 'L'-shape with her body. Spawning activity can sometimes be encouraged by pushing the temperature up a couple of degrees but to no higher than 27°C/80.6°F. Without caves present, expect nothing.
When the pair spawn, there can be some defensive behaviour from the male, who protects the immediate area while the female tends to the young. For the first nine to ten days she may make no appearance at all and will hide away while the male patrols.
At this stage, removing any community bottom dwellers would be wise because they may be struck by the defensive male — especially inoffensive fish like Corydoras that may stumble into the target area quite by accident.
On emergence, you should note quite large fry — which is great as it makes feeding simple! Artemia nauplii are taken (though not ideal), and finely crushed, protein-rich flake food and fry food is soon accepted. Expect the parents to stay with the young for three to four weeks until they eventually start to drift apart.
You need do nothing but feed, sit back and watch as all of this unfolds. And being peaceful, colourful fish in high demand, many retailers are even sympathetic to rehoming your offspring. Get them up to a decent size and you may even be offered a credit note for your efforts.
Note that the pH value of the water the fish breed and rear in has an affect on the sex ratio of the young. At a pH of 7.0, there’s an approximate balance of males to females, though as the water becomes more acidic the number of females increases considerably.
Fresh and green food for thought
All Pelvicachromis species get referred to as omnivores in stores, but the reality is of a strongly herbivorous fish with a taste for algae types and one that ingests a fair amount of sand into the bargain.
In studies conducted on wild fish, crustacean food was found in the bellies of under a quarter of all Kribs with detritus and higher plant matter (fragments of leaves and stems) being found in the majority.
What might be of surprise is the amount of algae ingested. Diatomaceous algae (think the sludgy algae that sometimes occurs on substrates) featured highly, as did blue-green and plain green algae types.
In every single belly looked at, sand was present making it rather clear that the fish were ingesting substrate as they rooted around for algae and detritus. It’s suspected that they even digest the nutritious biofilm that forms on individual grains.
In the aquarium, plant-based foods should be abundant, and Kribs will eventually disassemble softer leafed plants in the tank.
When choosing a food, look carefully at the packaging. Many ‘plant’ foods or algae flakes actually contain very little greenery, and the main ingredient will be fish.
Ideally, you want a veg-heavy flake food if you want fish that aren’t distorted or stunted.
Supplement with plenty of fresh greenery such as blanched spinach and dandelion, flaked pea, and any of the seaweed products frequently marketed for marine keepers.
If you are supermarket shopping, don’t be shy; acquire a little nori seaweed for your fish — I am sure the irony of being fed a sushi ingredient will be lost on them…
What the dither?
Dither fish are smaller fish and cohabit sympatrically with other species. They act as a good indicator to other fish on the presence of predators. Like a landed flock of birds, dither fish will scatter and vanish when threatened.
This presents an excellent visual guide for those fish with the sense to watch them. When dithers are out and about, it’s a good sign that the coast is clear, but if they suddenly disappear then it might be time to do the same!
Small dither fish in aquaria are often species like Zebra danios that are always out and about and immensely active. Their presence reassures more nervous fishes and encourages them to come out of hiding in to the open.
Be careful not to choose dither fish that are too ravenous or aggressive. You may find that adding too hostile a dither fish to a tank has the reverse effect, and the very fish you want to encourage out becomes all too aware of the risk to its fins if it does emerge.
Common name: Rainbow Krib.
Scientific name: Pelvicachromis pulcher.
Origin: Nigeria, Cameroon, Benin.
Size: Male 12cm; female 8cm.
Notes: Widely available, though wild caught specimens rare.
Don't forget that PFK is now available to download on the iPad/iPhone.