Genetic diversity of a cichlid fish population after 100 years of isolatio

Abstract

High rates of species radiation have been recorded in Cichlids of East African lakes. The current study focused on a population of Nile tilapia (Oreochromis niloticus) found in a crater lake (Lake Crocodile) that occurs within the Central Island of Lake Turkana. The population separated from Lake Turkana about 100 years ago and has since then existed in isolation. This study aimed at assessing the existence of genetic differences between the Lake Crocodile Nile tilapia population and other closely related Nile tilapia populations from Lake Turkana, Lake Baringo and River Suguta. Genetic differences between the populations were evaluated using two mtDNA markers, and 16 microsatellite markers. Significant genetic differences (p > 0.05) were observed between the Lake Crocodile population and the other studied populations within the region. Despite the shared ancestry between Lake Crocodile and Lake Turkana, genetic differences were observed between the two populations. This can mostly be attributed to the lack of gene flow and environmental differences between the two populations.