Genetic characterization of an unknown and endangered native population of the Nile tilapia Oreochromis niloticus (Linnaeus, 1758) (Cichlidae; Teleostei) in the Loboi Swamp (Kenya)

Nuclear and mitochondrial DNA polymorphism were studied in a number of natural populations of the Nile tilapia Oreochromis niloticus (Cichlidae; Teleostei) from East Africa in order to determine the origin of a recently discovered population from a warm water spring, the Lake Bogoria Hotel Spring, an affluent of the Loboi Swamp. This population was initially considered to have been introduced from other sites within the region. Its significant and unique genetic variability (high microsatellite and mtDNA polymorphism, highly significant Fst values and the presence of private alleles) indicate however that it is an entirely new and formerly unknown natural population that had escaped earlier studies of this species. This natural population, that represents a significant genetic resource, is threatened by extensive human encroachment of the Loboi Swamp.