A note on recent advances in the genetic characterization of tilapia stocks in Lake Victoria region

Oreochromis esculenta, the original "ngege" is virtually extinct in Lake Victoria, and is limited to satellite lakes and reservoirs in the greater Lake Victoria region. Oreochromis variabilis can still be found in Lake Victoria and some satellite lakes in the Kyoga System, but in small numbers and only at a few localities (WANDERA and KAUFMAN, unpub. data). Little is known about the influence that species translocations have had on the genetic structure of these crucial fishery species, and even the source of the parent stocks for the introductions remain obscure. Genetic variability was examined within and among allopatric populations of three species in the tilapiine genus Oreochromis: O. esculentus (endemic to Lakes Victoria and Kyoga), and two exotic species introduced to Lake Victoria in the late 1950's to supplement the failing fisheries for native tilapiines, O. niloticus and O. leucostictus.