Banjo catfish

Water parameters

Tolerated range for this species. Aim for the middle of each band rather than the extremes.

Tank and habitat

Substrate: sand.

Behavior

Plant interaction: plant safe.

Typically wild-caught; acclimate slowly.

Feeding

Takes sinking carnivore pellets, frozen bloodworm, live blackworms, and small or chopped earthworms. The fish is strictly a night feeder, so food has to land near it after the lights go out. In a community tank it is easily beaten to food by anything faster, so the only reliable way to feed it is to drop a portion directly onto or near its known hiding spot after dark. The presence of waste near that spot in the morning is the practical way to confirm it is actually eating.

Nocturnal feeder; drop food after lights out.

Compatibility

• Shaped like the instrument: a broad, flat head and a narrow tail. Buries itself in sand with only the eyes above the surface and stays there for hours or days at a time. Activity is almost entirely after dark
• One of the least active fish kept in the hobby. Anyone who wants to actually see their fish during the day should pick something else
• Effectively peaceful, because it has no interest in its tankmates. Compatible with anything that will not bother it
• Will eat small fish and shrimp at night by sitting on the substrate and ambushing whatever walks across its mouth, so it is not a safe addition to a shrimp tank or a tank with very small fish such as neon tetras
• Easy to keep alive but easy to accidentally starve. The trap is not that the fish refuses food but that faster tankmates take it all before the banjo cat moves out of cover

Origin and habitat

A small, leaf-shaped catfish in the family Aspredinidae, described by Cope in 1874. It comes from the lowlands of South America, specifically Brazil, Peru, Bolivia, and Uruguay, where it lives in the slow, shady margins of forest streams, ponds, and small lakes with sandy bottoms covered in leaf litter. The mottled brown body and flattened shape make it look like a piece of dead leaf, and it relies on that camouflage rather than swimming away from threats; the species will not normally bolt even when a net is dropped over it. Bunocephalus is the largest genus in the family, holding several undescribed species along with the named ones, and B. coracoideus is the species that turns up most often in shops and the largest of its genus. The Spanish-language name guitarrita means 'little guitar', a description of the body shape as seen from above. Adults sold in the trade are usually around 11 to 15 cm long. Members of the family occasionally shed their entire skin, sometimes in one piece, and no one knows why. The species is essentially nocturnal: by day it sits buried in sand with only its eyes above the surface, or wedged motionless under a leaf, and almost all activity happens after lights-out. IUCN Least Concern.

Breeding

Spawning has been reported in aquaria but is uncommon. Maturity is reached at around 11 cm. The fish are very hard to sex visually; a gravid female is rounder-bellied than a male, but otherwise external differences are slight. Spawning happens at night and the eggs are scattered onto the sandy substrate; reports cite clutches of up to about 4,000 eggs. The adults eat their own eggs, so the standard approach is to move the eggs (or the parents) into a separate container of the same water once the spawn is noticed. Hatching takes around three days, and once the fry finish absorbing their yolk sacs they take microworm and newly hatched brine shrimp. Most accounts of successful spawning are accidental, with people finding fry in a mature, leaf-littered tank rather than running a planned breeding setup.

Common problems

The biggest problem with this fish is that owners assume it is dead. It buries itself in sand for days at a stretch and only emerges to feed at night, so people regularly write it off, only to find it months later during a substrate change. The way to confirm a banjo catfish is alive and eating is to drop sinking food (bloodworm, sinking pellets, finely chopped earthworm) near its known hiding spot after lights-out and check the next morning. In a community tank, starvation is a real risk: it is slow, nocturnal, and easily out-competed by anything that feeds during the day. The keratinized skin is rough and the spines on the fin rays will catch in fine-mesh nets, so use a small container to move them. Beyond those concerns, the species is tough and tolerates a wide range of water conditions.

Bioload

Further reading

• How to cycle a fish tank
• Stocking ideas by tank size