Banjo catfish

Quick facts

Adult size

12 cm

Lifespan

can live up to 8 years

Tank zone

bottom

Temperament

peaceful

Difficulty

beginner

Typically wild-caught

yes - acclimate slowly

Water parameters

Temperature

22–28°C

pH

5.5 to 7.5

Hardness

2 to 15 dGH

Tank requirements

Minimum volume

80 L

Minimum length

60 cm

Flow

low

Lighting

dim preferred

Substrate

sand

Hiding spots

needed

Feeding

Diet: carnivore, feeds primarily at the bottom.

Sinking carnivore pellets, frozen bloodworms, live blackworms. Feeds strictly at night; drops food near it after lights-out. Easily outcompeted by active feeders. Check that it's actually eating by looking for waste near its hiding spot in the morning.

Nocturnal feeder; drop food after lights out so it can eat without competition.

Compatibility

• Shaped like a banjo: flat head, narrow tail stalk. Buries itself in sand with only the eyes visible. You will think it's dead. It's not. It does this for 23 hours a day
• One of the least active fish in the hobby. It sits in one spot, buried, for days at a time. Movement happens at night. If you want something you'll see, buy something else
• Peaceful with everything because it ignores everything. Compatible with any fish that won't eat it
• Will eat shrimp at night. The ambush is how it feeds in the wild: sits motionless on the substrate until something walks over its mouth
• Easy to keep alive but easy to accidentally starve. The main failure mode is not starvation from refusal but from faster tankmates eating all the food before the banjo catfish moves

Habitat

Native to rivers in the Amazon basin, Bolivia, Paraguay, and Uruguay. Found buried in sand and leaf litter on the river bottom. The flattened body and rough textured skin provide camouflage against sandy substrates. Multiple Bunocephalus species are sold under the same common name.

Breeding

Rarely bred in captivity. Scatters eggs on the substrate after a large water change with cooler water. The flat body shape makes it nearly impossible to sex externally, though gravid females are slightly plumper. Fry are extremely small and need infusoria. Most breeding reports come from accidental spawns discovered by finding tiny fry, not intentional breeding projects.

Common problems

The main issue is people thinking they're dead. Banjo catfish are among the most sedentary fish in the hobby. They bury themselves in the substrate and remain motionless for days or weeks, emerging only at night to feed. Owners regularly assume they've died and can't find the body, only to discover the fish alive during a substrate clean. Ensure they're actually eating by placing food near their hiding spot after lights out and checking for leftovers in the morning.

Bioload

Bioload coefficient: 2.0 (medium catfish that barely moves and eats infrequently; low waste for its size).

Bioload coefficients are calibrated against the neon tetra as the anchor (1.0). See the methodology page for the formula and how each value was derived.

Further reading

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