African Brown Water Snake

The Afronatrix genus, which includes A. anoscopus, is considered unique when compared to other members of the natricine subfamily in that it has lateral keels on its subcaudals. Additionally, it exhibits subocular scales, and will have a minimum of 21 dorsal scale rows. Its hemipenis anatomy has strong similarity to some Asian natricine snakes in that it is only partially bilobed and asymmetrical. This along with biochemical data suggests a close relationship between the two species. Its dentition is described as syncranterian (firmly fused to the jawbone without sockets).

Has a patchy distribution across West Africa, with confirmed records in Liberia, Nigeria, Senegal, Sierra Leone, Côte d'Ivoire, Ghana, Guinea, and Cameroon.It is likely present in other West African countries, but limited survey reports have resulted in a lack of records from these areas. It was reported in 2011 that the African brown water snake is the most abundant snake species in the rainforests of southeastern Guinea. The high population density of this species in many West African streams, along with dietary evidence, indicates that this snake plays a key role as a primary fish predator in these ecosystems.

A. anoscopus eats fish and amphibians. Studies in Nigeria show that it feeds on frogs, including Silurana tropicalis, Ptychadena spp., and Bufomaculatus, as well as fish like cyprinids and mudskippers. Juveniles eat more tadpoles, while adults consume more fish. This change in diet as the snake grows is similar to patterns seen in some European Natricinae like the grass snake. It hunts in freshwater swamps, rivers, and streams, and sometimes in brackish water.