Will Checkerboard cichlids suit my set-up?

I am hoping to get some Checkerboard cichlids for my 200 l aquarium. It has a length of 100cm, a temperature of 27.5°C and an oversized filter. The substrate is silver sand, and it’s heavily planted, with bogwood and branches and a few rocks, leaf litter and Savu pods. The pH is 6.8–7 — I use tapwater, but there are peat granules in the filter. Water changes are carried out every two weeks, meaning nitrate and nitrite is always low. Lighting is quite dim, but there are floating plants. 

The tank holds two Vaillant’s gouramis, six Congo tetras, eight Cardinal tetras, an L168 butterfly pleco, eight mixed corys, eight Shadow catfish, six Bentosi tetras and some Amano shrimp.

If Checkerboard cichlids are suitable, would you recommend a pair or harem?

SAM PUTNAM, EMAIL

The Dicrossus filamentosus in the trade have usually been bred in the Czech Republic. Image by Svenska, Creative Commons.

That sounds like a great set-up for Checkerboard cichlids! There are two species — Dicrossus maculatus with the heavier checkerboard pattern on its body and shorter fins, and D. filamentosus, with that beautiful lyretail. D. maculatus are the cheaper of the two and usually come in wild caught, while D. filamentosus commands a premium and is
bred in the Czech Republic by suppliers
of Apistogramma. 

Both will come in small and not looking like they do in the pictures, but give them the right conditions, like it sounds like you have in your tank, and they will thrive. 

Juveniles will not be easy to sex so start with a group, with the aim of eventually obtaining a pair. Juveniles do shoal in the wild so will get on fine, but once those males hit 5cm and start to colour up they will want a space all of their own, and I would only look to keep an adult pair in a tank of your size long term. 
JEREMY GAY

Can I keep a turtle with a puffer?

I have a tank containing a five-year-old Musk turtle (it only eats worms and pellets). Could I keep a Hairy puffer in the same aquarium?  

KITTY JACKSON, EMAIL

Assuming you’re talking aboutTetraodon baileyi, this species is a lot like other ‘lurker’ pufferfish in preferring habitats with brisk currents and plenty of oxygen. They like to lurk among smooth pebbles and driftwood, where their cryptic colouring helps them to blend in. While they don’t move about much, when prey does move into view, they can accelerate rapidly enough to snap up small fish and crustaceans that get too close to them. Because they are relatively inactive they can be kept in fairly modest aquaria: an adult specimen around the 10cm mark will be perfectly content in a well-filtered and well-maintained 90 l tank.

Their modest requirements have made them popular with people interested in oddballs. Buying a single tank and all the accessories won’t be too expensive, and water changes will be quick to do, which is important for fish that are both greedy and very sensitive to high nitrate levels.

Musk turtles are nice little beasties, but like all turtles they’re not compatible with aquarium fish. Turtles are heavy polluters which means that the water in their tanks rarely has zero ammonia and nitrite values, and nitrate levels rise alarmingly between water changes because of the sheer quantity of food given to them. So while you might see fish and fully aquatic turtles combined in public aquaria, it’s almost never practical to do in the
home aquarium. 

In addition, pufferfish tend to be snappy, with a bite-it-and-see approach to finding food. While I doubt even an adult puffer will be able to crack through the shell of your Musk turtle, the flippers and tail are a bit more vulnerable.

 So I’m afraid that I really wouldn’t recommend that you mix the two.
NEALE MONKS

What is this strange thing in my tank?

I recently set up a planted Fluval Edge 23 l/5 gal tank, after a few weeks and some new occupants later I noticed this ‘creature’, which I’ve since discovered could be an aquatic slime mold — but that’s where the info ends unless you understand scientific talk.

It seems to move around the tank, along the wood, occasionally disappearing into the substrate. Whilst I never see movement, if left for a period of time it will have relocated to another part of the tank.

For now, I’ve manually removed it with a syphon and toothbrush. But where did it come from and how do I stop it coming back?
LUKE GLOVER, EMAIL

Slime molds — those that are big enough to see, at least — are uncommon in aquaria, though small colonies could easily go unnoticed, so it’s hard to say whether or not they’re a normal part of freshwater set-ups.

What we can say is that they’re a bit like fungi in habits, consuming organic matter such as decaying plant material. That being the case, they’re not likely to threaten your fish directly. but just like fungi, they are a sign that’s something amiss with the aquarium. If you can see slime molds or tufts of fungi, there’s something in the tank decaying that they’re digesting. In doing so they’re producing waste products that the filter has to deal with, ultimately raising nitrate levels between water changes.

The fact that your tank is very small highlights some possibilities. A deep substrate can be very good at accumulating debris that the slime mold could be feeding on. It’s also very easy to overstock a small aquarium or overfeed the tank residents, and the faeces and uneaten food will provide food for your slime mold.

The one time I’ve dealt with slime molds in an aquarium was after adding fresh wood as decoration, as opposed to cured bogwood. Again, organic material in the wood provided food for the slime molds.

A lack of water circulation can also prevent organic debris from ending up in the filter where it can be processed by the bacteria, providing more food for the slime mold.  
NEALE MONKS

What can I keep with this bossy fish?

I have just got into fishkeeping and I have a 40 l/11 gal tropical tank that currently has two Serpae tetra in it. I was wondering what tank mates I could add as everything I have read about them has told me they are quite dominant. I would like some colourful mid to top dwellers if possible.
DANIEL FAIRLIE, EMAIL

Serpae tetra, Hyphessobrycon eques, do indeed have a somewhat deserved reputation as pugnacious, ‘nippy’ fish and will often dominate and bully less robust species. The best way to lessen the chances of this occurring is to stock them in larger numbers; I would recommend a bare minimum of ten but even then they may still be a problem with some fish. Unfortunately, your tank is too small for this as these active fish can reach 4cm/1.6in long. 

Ember tetra, Hyphessobrycon amandae.

My recommendation would be to return your two existing fish to the shop you bought them from, and replace them with a group of at least six Ember tetra, Hyphessobrycon amandae, which share similar burnt orange colouration, but typically grow about half the size and are not aggressive like the Serpaes. 

Adding some hardy live plants such as Cryptocoryne and Anubias will provide more cover and bring out better colour in your fish, and then perhaps you could consider a few Sparkling gourami, Trichopsis pumila, to fill the upper layers (add some floating plants if you do) and maybe a group of five Kuhli loach, Pangio semicincta, for the bottom.  
BOB MEHEN

Can I get this pump to run more quietly?

My air pump is very noisy and non-fishkeeping family members are complaining. How can I make it quieter? It has a really annoying rattle and hum noise, which is upsetting the peace of my aquarium.
MATT FLYNN, EMAIL

Some air pumps are quieter than others so that may be the first factor. The second is the power of the pump. Larger air pumps generally make noise than smaller ones. 

What airline are you using? Clear PVC 6mm airline is the most common although it can get brittle over time, causing rattling if it touches and vibrates against a cabinet wall. It also becomes stiffer, causing your pump to ‘walk’ across a space until it hits a cabinet wall and itself cause lots of noise and vibration. If using PVC, swap for soft silicone airline.

Non-return valves cause back pressure and noise, but you definitely need these. Some are more supple than others though, which I test by blowing through them to see which one allows airflow the easiest. Try new airline and a new valve, and check that the air filter pad isn’t blocked or restricted.

Where the pump is situated can also be a factor. A cabinet can act like a speaker box, amplifying noise. Try placing a Tupperware container over the pump with a gap underneath to allow air in. 

Many air pumps also have provision for vertical mounting, so try that if possible — or you could even hang it with string. Take the contact with hard surfaces away and any noise should be reduced dramatically.  
JEREMY GAY

Can I keep a plec in my mbuna set-up?

Strictly speaking there aren’t any suckermouthed catfish in Malawi cichlid habitats. so I would leave them out. There is an African species called Chiloglanis, although this is a river fish, not a deep lake fish, and it’s not easy to keep by any means. Don’t opt for them.

That leaves you with South America and Asia. Any wild caught L-number will be unsuitable because of their preference for soft acidic water and once the algae has gone you won’t be able to feed them. Your Africans will eat any algae wafer you drop in and the plecs are likely to starve.

From Asia there are the hillstream loaches — again specialist stream fish and sensitive — Garra spp., which are tougher but will be outcompeted and are not all biotope correct. There is one species though, Gyrinocheilus aymonieri, which is the bane of many tropical fishkeepers’ lives. It is a good algae eater but becomes territorial as it grows, much like Malawi cichlids, so is often returned to the shop for being a nuisance.

If you could get a 10–15cm/4–6in specimen which has been returned to a shop it would be tough enough to put up with your cichlids, carve out a living eating algae and give as good as it gets in terms of squabbles.

There is a tank bred suckermouth option, and that is the generic bristlenose catfish — the type which you see regularly for sale as small juveniles. My friend added some to his large mbuna tank 11 years ago and they are still there to this day. They are now large adults and in good condition, although the lack of suitable Malawi cichlid proof caves means that he has never had fry from what are usually very prolific breeders. That, or the hard water is preventing them
from breeding.

So if you have to, tank bred bristlenoses or adolescent to adult Gyrinocheilus are your best options, although it will be a compromise in terms of water hardness and feeding any extra foods will prove difficult.

Some Malawi cichlids are better grazers than others. The best are probably Labeotropheus, followed by Petrotilapia and Tropheops, although no cichlid will remove the green from your front glass. Use an algae magnet or scouring pad for that.
JEREMY GAY

How do I worm my fish safely?

I've learnt the hard way that you really can't afford to skimp on quarantining new fish!

I have a heavily planted 120 l tank with around 15 Amano and Red cherry shrimp, five false Julie corys and one surviving Fork tailed blue eye. The blue eye was once one of eight along with two elderly but much loved guppies — until I was foolish enough to add a few more blue eyes straight into the tank. 

Fairly early on it seemed that two of the new fish weren't happy and seemed to not be eating. Then came a period of regularly dead fish and much desperate searching for cause and diagnose.

Eventually we realised we had Camallanus worms. Treatment seems to be a nightmare and the Internet is full of confusion, with lots of sites recommending treatments that don't seem to be available in the UK or advising bird dewormers which I'm hesitant about.

I understand the dewormer would kill my shrimp and some sources seem to say corys might struggle too. Should I move the shrimp and risk the corys (they don't seem to have any signs of infection)? Can the shrimp carry the infestation and re infect the tank? Is there a different medicine I should be using? 
JENNY MARCHANT, EMAIL

You don’t mention how you arrived at your diagnosis of Camallanus. Diagnosis requires the observation of one or more red-brown worms (up to 2cm/0.8in long) protruding from the fish’s vent, or the discovery of the worms within the gut of a dead fish.  

Camallanus worms in the gut of a fish.

Assuming you have observed the actual worms, then we need to consider a few points about Camallanus infections: there are several species of Camallanus and they infest various freshwater fishes, including guppies. Living within the fish’s gut, these worms remain out of sight — so you may not have detected them even if you had quarantined your new fish (although quarantine is always a good idea). Generally, it is only when one or more female worms protrude from the fish’s vent to shed their larvae that a Camallanus problem is discovered. Low numbers of worms in the gut may cause no obvious disease signs but heavy infestations can lead to body wastage and can be fatal. 

Fish acquire Camallanus through eating worm-infested copepods (tiny crustacean relatives of water-fleas, sometimes sold as live food).  In the case of Camallanus cotti (which infests guppies, Betta, and other species), some experts believe that fish can additionally pick up this worm directly, by ingesting free-living worm larvae in the water. There is no evidence, to my knowledge, that shrimps will harbour Camallanus.

As for treatment — and this assumes you have a confirmed diagnosis of Camallanus — I would choose one of the commercial fish wormers that contains either Flubendazole or Fenbendazole as the active ingredient. These wormers are reportedly toxic to shrimps so you will, unfortunately, have to treat all your fish (including the corys) in an isolation tank — I suggest isolating them for four weeks. You may need to re-dose every week or so during this isolation period — but follow the manufacturer’s instructions.        
DR PETER BURGESS

Should I switch off my filter when I feed my fish?

I am new to fishkeeping and I recently tried a food claimed to feed fish at different levels in the aquarium. When I added it most of it went straight down to the bottom of the tank due to the flow of the water. Is there a way to stop it sinking so quickly? Is it better if I turn my filter off when I feed the fish?
G. REES, EMAIL

It really depends on what type of filter you have and how you position it. 

Most internal filters return water to the tank horizontally, which should produce a flow across the tank, (and often weakly back again toward the filter as the flow deflects off the opposite side). This should mean that any sinking food added will remain suspended in the water column for a short time as it sinks. 

External filters generally have a similar effect but are more adjustable, so it is possible to position the return pipe or spray bar to send the water straight down to the tank floor, and this would rapidly wash any food down with it. 

Some tanks have filters that are situated in the hood and work by gravity with the water dropping through them and then back into the tank; these can make a fierce downward flow as well. If your filter is pushing water downwards then it can be a good idea to switch the filter off during feeding to prevent this — just be sure to switch it on again afterwards! 

Many fish foods have a mixture of densities in the one pack, so some will float, some sink rapidly and some slowly. In theory this should offer most types of fish a chance to feed. It might also be worth considering feeding in smaller quantities so the fish can gobble up most of the food before it reaches the bottom. 

Of course any bottom feeding species such as Corydoras will appreciate the food that sinks to the substrate.
BOB MEHEN

Can I keep my male dwarf gourami without a mate?

I have a healthy male Dwarf gourami but I have lost three females, all of which have wasted away. He doesn’t seem to be bullying them — they just seem to become skinny, stop eating and then hang about in one corner of the tank. I’m not inclined to try another, so will he be OK on his own — or should these fish really have a mate?
LYNN WOODS, EMAIL

Dwarf gouramis are an old aquarium favourite, and rightly so given the lovely colour displayed by the males. Native to India, Pakistan and Bangladesh, the fish seen in the hobby are largely commercially produced in Singapore. Sadly many of these fish are plagued by a nasty disease known as ‘Dwarf gourami iridovirus’, some of the symptoms of which are similar to those you describe seeing in the females you have lost. This disease is untreatable, but the fact that the male is unaffected could be down to a natural immunity. 

However, the males of this species are also well known for bullying and pestering females, especially if the tank is too small or doesn’t offer enough cover in the form of dense vegetation.

Lush floating plants are ideal for this, allowing females to hide away from the male’s unwanted attentions. As you have already lost three females it seems to me that even though you haven’t noticed any bullying it is still the most likely cause of their demise. A well-established healthy male will see each new female as a potential mate and immediately begin trying to impress her, regardless of her condition. 

This probably means the new fish have no time to settle in and feed up and simply fade away. 

My advice is to keep the male by himself. He won’t suffer from being kept alone and you’ll be able to enjoy his gorgeous colouration without worrying about a harassed and sickly female.
BOB MEHEN

Is there really such a thing as a freshwater seahorse?

Freshwater seahorse — real or just a myth? Heiko Bleher explains...

I’ve searched for freshwater seahorses for years. I even went to Lake Maracaibo and looked for the one described from the Mekong without any success.

It was described by Roule in 1916 as Hippocampus aimei, but no fisherman has ever seen one.

In a museum in Paris I looked at type specimens and in each was a nail hole! When Roule arrived in Laos he saw them nailed to the hut of a fisherman who told him they were from the Mekong.

After my museum discovery others became aware and Lourie et al revised it in 1999 and found that Roule’s two ‘freshwater’ seahorses were marine species — H. spinosissimus and H. barbouri. Both come from the Indo-Pacific: the former also being found in shallow estuaries of Thailand and the latter in estuaries of the Mekong.

The third seahorse I went after might be the only freshwater one on earth. It lives, or has lived, in Titikaka, the world’s highest navigable freshwater lake. I found the specimen pictured in the Museum Tiwanaku near the lake.

Something strange happened during my last visit. I climbed the highest island in the lake and at nearly 4,600m/15,000’ above sea level met a man claiming to be 120 years old and he recognised my photograph immediately, saying: “Yes, it lives here”.

He explained where he had seen it a long time ago, but the location was on my unexplored Peruvian end of this lake and I had no time to investigate as my flight out was due next day.

If the introduced trout and salmon and escaped exotics have not made the only freshwater seahorse extinct in the lake, as they have already with many endemic Orestias species, we might one day be lucky.

Polansky’s 1943 specimen from the lake, the sample at the Museum Tiwanaku labelled as Hippocampus titicacanesis (pictured above) is proof that there was a freshwater seahorse.

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