Cross basin

'Barbus' sublineatus is a widespread West African barb found in river basins from Senegal east to Cameroon, including the Niger and Volta. It is very variable in patterning and can be difficult to identify: Upper Niger fish show three elongate midlateral markings, Middle Niger fish a continuous band and Volta fish four spots. It may prove to be a complex of closely-related species. Little is known of its captive care.

Chromidotilapia guntheri is a mouthbrooding cichlid from coastal drainages of western Africa between Liberia and Cameroon, plus the Niger and Benue. It occurs in a number of geographic forms, with fish from Cameroon tending to show dark blotches on the dorsal fin. A benthophagous omnivore, it sifts mouthfuls of substrate for food, and the male broods the eggs while the female defends the surrounding territory.

The six-barred panchax, Epiplatys sexfasciatus, is a killifish from coastal regions between Gabon and Ghana. Well established in the hobby in several forms, it has a confusing taxonomy, and some authors restrict it to northwestern Gabon and Equatorial Guinea and treat other populations as subspecies. It mostly inhabits freshwater swamps and minor tributary streams, and is relatively easy to breed.

Parachanna africana is an African snakehead found from Benin to Nigeria, in lowland coastal rivers draining into the Gulf of Guinea. Sometimes called the 'Niger snakehead', it is uncommon in the trade, and its name is sometimes misapplied to P. obscura. A series of 8-11 dark chevrons along the body identifies it, though these may not show depending on mood. It is best kept in a species-specific aquarium with a tight-fitting hood.

The two-striped lyretail, Aphyosemion bitaeniatum, is a killifish from lowland coastal regions of Togo, Benin and Nigeria. Its range reaches the Cross River delta and some inland localities along the lower Niger River. Populations in Cameroon, Equatorial Guinea and Gabon are now considered to represent other species.

The steel-blue killifish, Fundulopanchax gardneri, is native to the Cross River system in Nigeria and Cameroon and the Benue River drainage. Also known as Gardner's killi or blue lyretail, the common aquarium forms are among the best choices for those new to killifishes. Wild populations come in numerous colour forms, three of them described as subspecies. Its eggs can withstand a period of drying but will also hatch when kept submerged.

Fundulopanchax gresensi is a killifish known only from a small area in the upper Cross River basin, western Cameroon. It has been collected from shallow, swampy sections of forested streams, some of which may dry out in the dry season. The commonest hobby strain is known as 'Takwai'. It jumps well, so the aquarium needs a good cover.

The two-banded lyretail, Aphyosemion bivittatum, is a killifish that appears restricted to coastal plains along the Cameroon and Nigeria border. Its range includes the Korup and Cross River National Parks, and the type locality is close to a waterfall on the Ndian River in southwestern Cameroon.