Abstract

Random amplified polymorphic DNA (RAPD) marker analyses were used to profile the ‘ecological explosion’ of the introduced Oreochromis niloticus in the basins of Lakes Victoria and Kyoga in comparison to its putative origin of Lakes Edward, George and Albert.  O. niloticus is currently the dominant tilapiine in Lakes Victoria and Kyoga basins following its introductions from the Lakes Albert and Edward starting in the 1920s. The populations from the Lake Victoria basin were more similar to the putative source population of Lake Edward, while the populations from Lake Kyoga were more similar to the Lake Albert population. Lake Kyoga basin populations were less diverse than those of Lake Victoria basin, consistent with the hypothesis that introductions into Kyoga were more recent and/or that a more diverse set of introductions contributed to those of Victoria basin. Wider differences between Lake George and Lake Edward populations relative to distant populations was attributed to the direct transplant of Albert strain into George by a fish processing establishment in the 1970s. RAPDs offered a quick and inexpensive molecular tool to discern fish populations that could be adopted for management of the fisheries given the recent volatile species/populations changes and/or losses in Lake Victoria Region.

Key words: RAPDs, Oreochromis niloticus, Lakes Victoria, Kyoga, Edward, Albert, George.