The nsess (Stomatepia mariae) is a species of cichlid endemic to Lake Barombi Mbo in western Cameroon.

[2] It is critically endangered because of pollution and sedimentation due to human activities.

It is potentially also threatened by large emissions of carbon dioxide (CO2) from the lake's bottom (compare Lake Nyos),[1] although studies indicate that Barombo Mbo lacks excess amounts of this gas.

[3] The nsess can reach up to 12 centimetres (4.7 in) in standard length and is predatory; it sometimes steals prey from the freshwater crab Potamon africanus.

This tilapiine cichlid-related article is a stub.