The Gymnotiformes are a group of teleost bony fishes commonly known as the Neotropical or South American knifefish. They have long bodies and swim using undulations of their elongated anal fin. Found almost exclusively in fresh water, these mostly nocturnal fish are capable of producing electric fields for navigation, communication, and, in the case of the electric eel, attack and defense. A few species are familiar to the aquarium trade, such as the black ghost knifefish, the glass knifefish, and the banded knifefish.
Osteoglossiformes is a relatively primitive order of ray-finned fish that contains two sub-orders, the Osteoglossoidei and the Notopteroidei. All of at least 245 living species inhabit freshwater. They are found in South America, Africa, Australia and southern Asia, having first evolved in Gondwana before that continent broke up.
The family Mormyridae, sometimes called "elephantfish", are freshwater fish in the order Osteoglossiformes native to Africa. It is by far the largest family in the order with around 200 species. Members of the family can be popular, if challenging, aquarium species. These fish are also known for having large brain size and unusually high intelligence.
Gnathonemus is a genus of elephantfish in the family Mormyridae.
Marcusenius is a genus of elephantfishes native to Africa. Its members are highly diverse in size, with the smallest species reaching less than 15 cm (6 in) and the largest more than 1 m (3.3 ft).
Marcusenius sp. nov. 'Malindi' is a species of fish in the family Mormyridae. It is endemic to Kenya. Its natural habitat is rivers.
Mormyrus is a genus of fish in the family Mormyridae.
The African butter catfish is a species of fish in the family Schilbeidae. It is native to many major river systems in Africa. Other common names for the fish include butter fish, butter barbel, African glass catfish, lubangu, mystus catfish, silver barbel, and silver catfish. It was originally described as Silurus mystus by Carl Linnaeus in 1758.
The subfamily Mormyrinae contains all but one of the genera of the African freshwater fish family Mormyridae in the order Osteoglossiformes. They are often called elephantfish due to a long protrusion below their mouths used to detect buried invertebrates that is suggestive of a tusk or trunk. They can also be called tapirfish.
The Knoepffler's elephantfish is a species of elephantfish in the family Mormyridae being the only member of its genus. It occurs only in the Ivindo River and the Ntem River basins of Gabon and Cameroon. It reaches a maximum length of about 41 cm (16 in).
Brienomyrus is a genus of small elephantfish in the family Mormyridae from Africa.
Campylomormyrus is a genus of elephantfish in the family Mormyridae.
The Steindachner's Angolan mormyrid is a species of elephantfish in the family Mormyridae being the only member of its genus. It is found only in the coastal river basins in Angola in Africa. It reaches a length of about 10 cm (4 in).
Henry's mormyrid is a species of freshwater elephantfish in the family Mormyridae and the only member of its genus. It occurs in coastal river basins in West Africa, ranging as far southeast as the Kouilou-Niari River in Middle Africa. It reaches a length of about 29 cm (11 in).
Myomyrus is a genus of elephantfish in the family Mormyridae. Its members reach about 25–30 cm (10–12 in) in length and are restricted to the Congo River Basin in Africa.
Oxymormyrus is a small genus of elephantfish in the family Mormyridae. Its members reach about 25–27 cm (10–11 in) in length and are restricted to the Congo, Campo, Kouilou-Niari, Nyanga and Ogowe river basins in Middle Africa.
Paramormyrops is a genus of elephantfish in the family Mormyridae from Africa.
Petrocephalus is a genus of fish in the family Mormyridae. All the fish species of this genus are endemic to Africa.
Stomatorhinus is a genus of small elephantfish in the family Mormyridae.
