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Focus on community oddballs

Got a taste for oddballs but not the room to keep big ones? Jeremy Gay details some smaller species which are interesting and safe for the larger community.

Copyright © Practical Fishkeeping

Oddballs don’t have to be large and we are frequently asked about some smaller species and how to keep them. And what could be better than mixing unusual fish with your other species and not having to keep one fish in one tank?

Here’s a rundown on a few smaller oddball species with details on what they require and what they will mix with.

Initially, what defines an oddball? To me, it is a fish that doesn’t fit the usual fish-shaped mould. It may be coloured to be camouflaged, or shaped to look like something else. Oddballs are usually high in personality or character and kept more for their behaviour than colour. Many oddballs are predatory, meaning that they need a certain amount of intelligence in order to catch prey. This all adds to their appeal.

So what defines a small oddball? For the purposes of this article I have tried to concentrate on species that only grow to about 15cm/6”. With the right care you should be able to house a small oddball species in a tank of 91-122cm/3-4’ length and of standard width and height. This should also mean that keeping a small oddball species won’t break the bank.

Here are some of my favourites:

Bushfish

Also known as climbing perch, or climbing gouramies, bushfish come from the family Anabantidae. I’m concentrating mainly on the African species from the genus Ctenopoma and Microctenopoma as they can have interesting markings and can be kept not unlike gouramies or Paradise fish.

The Leopard Ctenopoma is a bit on the large size at 18cm/7” fully grown, but is the most commonly available of the climbing perch and looks great with dark blotches over a yellow body.

It’s hardy and will accept dead/frozen foods. It’s also commercially bred and acclimates well to life in an aquarium. Ctenopoma oxyrhnchum is worth looking out for and only grows to 10cm/4”.

Microctenopoma include the small but stunning Ornate Ctenopoma, Microctenopoma ansorgii, which, although more delicate than the others, is well worth looking out for and would even be fine in a 60cm/24” tank while small.

All bushfish will appreciate a well-planted tank with rocks and roots to provide shelter. A pH around neutral is fine, with temperatures in the mid to high 20s°C/78°F and above. Don’t combine them with fast swimming, boisterous tank mates like large barbs or large rainbows as they will steal their food.

Dwarf Synodontis like S.nigriventris would make perfect tank mates for bushfish, but, in the case of the Leopard Ctenopoma, only combine with fish too large to be swallowed, and about half their size.

Gobies
The goby family is huge, with most representatives being marine, but there are lots of freshwater and brackish gobies to interest the fishkeeper with a standard-sized tank.

Starting with the brackish species, the Bumblebee goby is a terrific, colourful oddball and tiny. It could easily be kept in groups in a nano tank and can also be bred. Make sure the specimens you buy are feeding well and maintaining weight.

Then there are the Knight gobies. These brackish fish only grow to a few inches in length (approximately 7cm) and are well behaved if given room to establish territories and not kept with small fish.

Males have longer dorsal and anal fins and the females a slightly yellow belly. Make sure they are well acclimatised, rested and feeding before you take any home from the shop.

Butis butis, or the bony snouted gudgeon, is one of my favourites and can be kept in brackish or hard alkaline water.

It much more fits the oddball description with its odd shape and brown mottled coloration and is a predatory fish. Butis are smaller oddballs that lie in wait to be fed. They can spin on a central axis and even sit upside down in midwater — and I think that adds to their appeal. They grow to 15cm/6”.

Batanga, Mogurnda and Dormitator are often confused as they look similar, but Dormitator can grow too large for the community, at 25cm/10’’. Mogurnda come from Australia and Papua New Guinea, meaning that if you house them with rainbowfish, you could create a biotope: no tiny rainbows, though, like Pseudomugil as they will be eaten.

Mogurnda are colourful and great additions to the community of medium-sized fish.

Small freshwater gobies are appearing more and more in the shops and they can be both plant friendly and compatible with small fish.

Endearing qualites include their ability to stick to the glass and those comical facial markings. Expect to see more availability in the future.

Catfish

Whether catfish can be called oddballs is always a fine distinction, but I think if any would qualify it would be the Chaca chaca. These look like a muddy leaf or a flat bit of wood and use their camouflage to enable them to lie near and then engulf prey.

These interesting-looking catfish aren’t very active and can be kept in relatively small tanks. Chaca chaca grows to 8”/20cm but we may actually be receiving Chaca bankanensis, a slightly smaller species that looks very similar.

The ideal tank for Chaca would be one filled with leaves and wood on a sandy bottom. Tank mates should be as large as the Chaca themselves or might be eaten, but also peaceful and slow moving. Don’t combine with anything that might pick at them.

Snakeheads

Dwarf snakeheads must be a contender as one of the best ‘proper’ oddballs available for the normal-sized tank. They’ve got attitude, are predatory and refuse to be tamed. They can even be colourful and present a breeding challenge too.

Perhaps the most famous snakehead species of late is Channa bleheri, named after PFK contributor Heiko Bleher who discovered it. This stunning species is colourful, stays small and quite readily available.

Although predatory, it can be kept with larger Botiine loaches and larger gouramies from the genus Trichogaster, and catfish.

However it has ability to escape. Any snakehead aquarium must have cover glasses and the cut out in the corners should be filled with old fish bags or netting to prevent escape.

Once a fish finds a possible escape route, it may spend all night, every night, jumping at that hole and trying to get through it. All the more reason then to present the fish with natural surroundings like wood and live plants so they have reason to stay.

Channa gachua is perhaps the most common dwarf snakehead available and one of the cheapest.

It arrives often in shipments coming through India and often wrongly labelled as Channa orientalis, a much rarer dwarf species. C. gachua is quite a stocky dwarf and hardy.

Again, it can be mixed with other fish of 7.7cm/3” and above and will feed on any meaty foods, from cockles and mussels to chopped fish. In a 122cm/48” tank you could keep a group of six. Heavily plant the tank to keep them out of each other’s line of sight.

Spiny eels

Most spiny eels make great additions to the oddball community, but for the purpose of this article I’ll nominate just one species, Mastacembelus circumstinctus, as it stays under the 15cm/6” mark. Spiny eels are well behaved and are only going to eat fish if small and on the bottom.

They will mix with each other in groups and with virtually any other fish species as long as they are not too boisterous. Spiny eels must have somewhere to hide. A pipe is ideal but, for the natural look, cover it in wood and rocks or use a large piece of well-soaked bamboo pole.

The biggest issue with all spiny eels is keeping weight on, especially when small. They won’t want to leave their hideout to find food, preferring to eat what floats past. Although timid, they will quickly learn to eat from your fingers and even take flake. Get a spiny eel hand feeding on flake and it will do well, gaining weight easily.

Keep the tank well covered and block up any access to internal filter chambers.

Pike top minnow

Want the shape and behaviour of a gar or a pike characin, but don’t have the room? Enter the Pike top minnow, Belonesox belizanus. This is large by usual livebearer standards, with females growing to up to 20cm/8”, although the male is much smaller.

When young, males and females look the same, though, when adult, males can clearly be identified by the large gonopodium.

They predate on small fish and insects that land on the surface of the water, though are peaceful by oddball standards and safe with any fish too large to eat.

They are being commercially bred for the hobby in the Czech Republic and are appearing in some specialist shops. Being surface swimmers, provide them with some floating plants for cover and combine with catfish on the bottom to help clear up.

Butterfly fish

I am not a fan of the Butterflyfish, Pantodon buchholzi, being kept in the wrong environment as it gets picked on and often goes hungry — yet put it in the right situation and this small relative of Arowana can be terrific.

Its cryptic shape and pattern makes it difficult to see which way up it should be, but this fish is perfectly adapted for moving stealthily along the surface, polishing off fish fry and fallen insects.

To do it justice, set the tank up with floating tree roots, floating plants, bogwood, sand and leaves. If you want a truly weird set-up combine them with Upside-down catfish.

Because they stick to the surface the whole time, how about lowering the water level so that you can better observe their behaviour, or even place them into a paludarium which is half water and half land?

Keep a group in a specially set-up tank and try to get them to feed on floating food sticks specially made for carnivores. In addition, supplement their diet with chopped fish and insects from a reptile shop.

Nandus nandus

This is one leaf fish I do advocate for captivity as it can be weaned onto dead foods and has great predatory behaviour akin to a Nile perch or a Tiger fish.

It will keep the diehard keepers happy with its feeding tactics, but won’t outgrow the tank. Sizes up to 20cm/8” have been recorded, but the near identical Nandus nebulosus is much smaller at about 12.5cm/5”.

What no pufferfish?

Many puffers fit into the small to medium-sized oddball bracket, but I haven’t included them here.

I strongly believe that puffers should be kept either on their own or mixed with their own species, where applicable, and not with other fish. That dentition is just too much of a risk.

Setting up for smaller oddballs

With their cryptic coloration and interesting behaviour, I think tank décor for oddballs should look natural. Use a fine sand or grit on the bottom, combined with bogwood branches, sunken roots and rocks.

Use wood and rocks to make caves and shady overhangs, as all nocturnal predators will need somewhere dark to hang out in the daytime. Let stem plants overgrow for that jungle look and floating plants will aid water quality, provide shade and even somewhere for bubblenesting species to breed.

Filtration needs to be able to deal with the protein-rich foods, so an external power filter is best, though snakeheads and bushfish prefer areas of slow flow so position the filter outlet pipe accordingly.

Lighting needs to be bright enough for plant growth, but use overhanging plants to shade areas beneath. You could even use a short light tube and light two-thirds of the tank. This will suit the oddballs and provide a moody effect.

To get the best from your fish, match your water to that of their natural habitat. Amazonian species should have soft, acid water and brackish species synthetic marine salt.

Suitable choice of tank mates

Choose tank mates wisely as they should live in harmony with your chosen oddball, not be stressed by them or cause them to be stressed.

Use other species as you would dither fish with cichlids. Ideally they should be too large to be eaten, but not nippy or boisterous enough to harass or steal food.

Tiger barbs fall into that nippy category and, in a shoal, can be a force to be reckoned with at feeding time. Large rasboras like Two spot or Greater scissortails are a better choice and very peaceful.

Don’t overstock your oddball tank as most are sedentary, solitary fish. They won’t appreciate competing for hiding places with their own kind, or other fish, and very territorial species like Red tailed black sharks could harass and even kill them. Give them space and a place to call their own.

Your oddballs are also specialised and could lose out to more competitive species like cichlids. If trying to train your Leopard Ctenopoma to take chopped fish, the last thing you want is an opportunistic Jack Dempsey or Jewel cichlid stealing it.

Oddballs to avoid

Flounder: Tropical species of flatfish from either South America or India that typically don’t do well. They are micro predators that don’t tend to acclimate well to captivity.

Elephant nose: An interesting group which ideally need a muddy bottom and a large tank to contain a group, yet they remain quite boisterous with each other.

Pipefish: Beautiful but far too difficult to keep long term unless you have a constant supply of tiny live foods.

South American leaf fish: Amazing camouflage, but needs small live shrimp and fish to feed on long term. If it can’t be kept for that duration on dead foods, it shouldn’t be kept at all.

Feeding the right foods

A piscivore, or fish eater, should be fed on fish — frozen ones. Supplement diet with cockles, mussels, prawns and reptile foods like locusts and meal worms.

If you can get your oddballs onto a food stick especially for them, then so much the better as these are complete foods and will provide the fish with everything it needs to grow and thrive.

FAQs

Can I have a community of oddballs and miss out the dither fish altogether?
You can, but first make sure that the oddballs themselves don’t clash in terms of water requirements or temperament. Butterflyfish would mix with bushfish and spiny eels. Snakeheads are quite competitive eaters, so, if mixed with say Chaca chaca, it is doubtful that the sedate catfish would get to any food.

I like the larger oddballs. Can I keep them in a small tank while small and then rehome?
A fish must have adequate room to exercise and a young specimen of a large fish could be kept in a standard tank while small. The tank must be upgraded as the fish grows, however, and here lies the problem.

Not enough people upgrade to 183cm/72” tanks and beyond, and the fish is taken back to the shop, or public aquarium in the hope of rehoming. Public aquariums are full to bursting and fewer shops are taking in very large fish these days — so the hobby is left with a lot of large fish needing good, long-term accommodation.

Keep oddballs that stay at a reasonable size and they will never outgrow your tank or strain your resources. Lots of places will rehome a beautiful Channa bleheri and you might even get something free in exchange, but, all being well, you will never have to rehome any of my featured fish — making them much more suitable choices.

This article was first published in the August 2008 issue of Practical Fishkeeping magazine. It may not be reproduced without written permission.

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Jeremy Gay 2560 (words, 12062 hits)
Published online: 09.15.08


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