Cornish Jack
The Cornish jack, Mormyrops anguilloides, is a species of weakly electric fish in the family Mormyridae, native to quiet waters in much of Sub-Saharan Africa
Length: Cornish Jack can grow to a maximum length of 1,5 meters.
Name: The common name “Cornish jack” likely originated from European settlers, who thought that this fish resembled the European pike, whose young is known as a “jack” in some parts of England. It is also known as “African carp”, a name that is used for several other species.
Where you can find them: In southern Africa it is restricted to the middle and lower Zambezi and the Buzi and Pungwe Rivers (Skelton 2001).
Ecology and Habitat: This is a demersal, potamodromous species. This species inhabits rivers and river mouths. Juveniles are found in marginal habitats whereas adults prefer deep quiet water and estuaries away from strong currents (Tweddle and Willoughby, 1982). It also occurs beneath Salvinia mats and in river estuaries in Lake Kariba. Juveniles prey on invertebrates, mainly shrimps and insect larvae, whilst larger individuals feed on small cichlids, minnows and labeos. It breeds during the rainy season (Skelton 1993) and is a fractional spawner (Alberet 1982, Kirschbaum 1995).
Feeding: They use electricity as a hunting tool to find prey and to move around. In addition to using their electric sensing capabilities for hunting, these fish can also distinguish between different electric wavelengths, which allow them to determine their school of fish. When young Cornish Jack feed on invertebrate larvae and crustaceans and when older on a variety of fish species.
Threat: In eastern Africa this species is threatened by fisheries and environmental disturbance. Intense fishing pressure with gill nets in certain areas of the lower Zambezi probably affects this species
