Results for “undulating”

G. niloticus is the only species in its genus and is utterly unique. Unlike other knifefish it has an extended dorsal rather thangiving rise to the alternative common name of upside-down knifefish. Despite this common name, it is actually more closely related to the Mormyrid group of species. It is a truly beautiful sight in motion despite its lack of bright colours, as it can move in virtually any direction with ease using its undulatingto 'steer'. It also produces a weak electrical d...

Like other members of the family Notopteridae this species differs from Gymnotiform knifefish in that its anal and caudal fins are fused together into one long, undulating fin running along the underside of the fish. There is only one other species in the genus. P. congoensis is a smaller, plain brown coloured fish found only in the Democratic Republic of Congo and is very rare in the hobby. P. afer is also infrequently imported and is one of the rarer knifefish species in the hobby. It can dev...