Mormyrus is a genus of elephantfish in the family Mormyridae, part of the African-centered order Osteoglossiformes. The atlas lists 29 species, found across a wide swath of the continent from Egypt and Kenya through the Democratic Republic of the Congo, Cameroon, Chad, Côte d'Ivoire, Ghana, and Benin — reflecting the genus's presence in both the Nile system and West and Central African river basins. Like other mormyrids, Mormyrus species carry an elongated, tapering snout — the 'elephant snout' that gives most species their common name — which they use, together with a weak electric field generated by an organ near the tail, to locate food and navigate in murky or nighttime water.
Mormyrus includes some of the larger elephantfish in the aquarium hobby, with adult sizes in the atlas ranging from about 5.5 in up to a substantial 39.5 in in the biggest river-dwelling species — sizes that put most Mormyrus well outside typical community tank stocking. The fish are prized by specialist keepers for their intelligence and their unusual electrolocation-based behavior rather than for color, and they generally need soft substrate, subdued lighting, and tankmates that will not out-compete them for food, since mormyrids can be slow, cautious feeders. Conservation status is mixed and only partly resolved: most assessed species sit at Least Concern, but five are listed as Vulnerable and a sizeable share of the genus is still Not Evaluated.