elephantfishes

Elephantfishes, commonly called elephantnose fishes, are a group of freshwater fishes in the family Mormyridae, within the order Osteoglossiformes. They are native to Africa and include numerous genera and more than 200 species. The name derives from the elongated snout seen in many species, which resembles an elephant's trunk and is used to probe the substrate for prey.

Most mormyrids are small to medium-sized, with a laterally compressed body. Colouration varies, often with muted tones and distinctive patterns. The long snout houses sensitive electroreceptors and mouthparts adapted to bottom feeding.

A defining feature of elephantfishes is their electric sense. They generate weak electric discharges with an electric organ in the tail and detect surrounding fields with electroreceptors in the skin, including ampullary and tuberous receptors. Discharges, or electric organ discharges (EODs), are used for navigation, object detection, and social communication, and EOD patterns are often species-specific. The brain of mormyrids is relatively large for fish and includes specialized regions for processing electric signals.

Ecology and behavior: Elephantfishes are typically nocturnal or crepuscular, spending daylight among submerged structure and feeding on invertebrates such as insect larvae and crustaceans. They inhabit rivers, floodplains, and slow-moving streams across sub-Saharan Africa, including blackwater habitats.

Reproduction and conservation: Reproduction is generally oviparous, with external fertilization and limited parental care; life histories vary by species. Some elephantfishes are kept in the aquarium trade, notably Gnathonemus and Mormyrops species, which require specific water conditions and ample hiding places. Habitat degradation and pollution threaten local populations in parts of Africa.