Elephantnose Fish

Gnathonemus petersii is one of the most well-known weakly electric fish in the hobby, native to the Congo and Niger River basins. Its dramatically extended lower jaw — a Schnauzenorgan — is packed with electroreceptors that detect prey buried in substrate and allow it to communicate with conspecifics via species-specific electrical pulses. It has the largest brain-to-body ratio of any vertebrate. Strictly nocturnal, it requires dim lighting, plenty of hiding places, and soft substrate to probe. Sensitive to electrical fields — avoid using unshielded pumps or heaters. Surprisingly delicate for an experienced keeper's tank.

Water: 23-28°C, pH 6.0-7.5, soft to moderately hard; pristine quality essential; tannins beneficial. Tank: Minimum 200L; dim lighting; thick fine substrate; dense hiding caves and driftwood. Feeding: Carnivore; live or frozen bloodworms, tubifex, small earthworms; hand feeding at night recommended. Breeding: Rarely bred in captivity; seasonal spawner in the wild linked to flood cycles. Compatibility: Keep singly or in groups of 6+; aggressive toward own species in small numbers; peaceful with calm mid/top-water fish.