Mokele-mbembe bichir
(Polypterus mokelembembe)

Polypterus mokelembembe is a species of the fish genus Polypterus, found in the central basin of the Congo River.

The last discovered and at the same time smallest species of the genus is Polypterus mokelembembe, which was described as a separate species only in 2006. Previously it was confused with P. retropinnis, in the trade it was often called P. lowei. P. mokelembembe is a resident of smaller blackwater streams in the Congo region and grows to about 25 cm in length.

Males and females can be easily distinguished, as in all Polypterus species, by the differently shaped anal fin, which becomes more than twice as large in the male as in the female. During mating, this anal fin is spread out like a bowl. The male swims side by side with the female during mating, encompassing the anal fin region of the female with the splayed anal fin, ensuring fertilization of the eggs released freely into the water.

The larvae have external gills and thus look very similar to newt larvae. Even tiny P. mokelembembe (the small ones pictured are about 5 cm long) have the coloration typical of the species.