[1] Despite its very small size, it supports 7 endemic species of coptodonine and oreochromine cichlid fishes (Coptodon deckerti, C. ejagham, C. fusiforme, C. nigrans, Sarotherodon lamprechti, and S. knauerae).

[2][4][5] C. deckerti is considered critically endangered due to pollution and sedimentation from human activities.

[6] A species of catfish from the genus Parauchenoglanis has been introduced to the lake, and this probably presents a serious threat to the endemic cichlids.

[2] The Ejagham cichlids are commonly considered a prime example of sympatric speciation within its two genera.

Studies indicate a level of secondary gene flow between the lake's species and relatives from nearby regions, and this likely facilitated the speciation (i.e., the Ejagham species not strictly the result of sympatric speciation).