Elephant Fish

About

The elephant nose fish (Gnathonemus petersii) is the most commonly encountered mormyrid in the hobby, and once you understand how it actually works, it becomes one of the most fascinating fish you can keep. That distinctive fleshy chin extension is not a nose at all but a sensory probe used to root through soft substrate in search of worms and insect larvae. Denying it a fine, soft bottom is genuinely doing the fish a disservice. It's native to the Niger and Congo River basins in central Africa, where it lives close to the riverbed in dim, often murky conditions. To compensate for poor eyesight, it generates a weak electric field from modified muscle tissue near the tail, and electroreceptors covering much of its body detect distortions in that field caused by nearby objects. Allowing it to navigate, hunt, and even communicate with other mormyrids in complete darkness. Its brain is proportionally enormous, and it can distinguish between species and even identify the sex of nearby conspecifics through electrical signals alone. In the aquarium, it is strictly nocturnal and needs low lighting along with plenty of cover. Toward its own kind it can be quite aggressive, so keeping a group requires a large, well-decorated tank. It generally leaves other species alone but should not be paired with boisterous or competitive tankmates. Water quality is critical. This species is genuinely sensitive to decline.