Genetic evidence of successful establishment of the Nile perch (Lates spp. L.) in East African lakes and implications for management
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Date
2012
Journal Title
Journal ISSN
Volume Title
Publisher
Management of Biological Invasions
Abstract
Nile perch establishment in novel ranges in East Africa is one of the most successful freshwater invasion stories in the recent history. It became ecologically dominant and well established in several lakes in the Lake Victoria Region in a period of less than 5 decades. Genetic diversity of both introduced and native populations were assessed and patterns compared in order to establish the genetic consequences of their introductions. Genetic variation was surveyed at both the mitochondrial control region (CR) and at nine microsatellite loci. A total of 527 Nile perch fish were sampled from 5 East African lakes: native source populations were examined from lakes Albert and Turkana while introduced populations were sampled from lakes Kyoga, Nabugabo and Victoria. Both types of markers revealed higher average genetic diversity for invasive species (HE = 0.70, h = 0.81) than for native source populations (HE = 0.66, h = 0.69). Both populations scored relatively higher than the average for freshwater fishes (HE = 0.62). Both native and introduced populations had 2 underlying genetic groupings in similar proportions as revealed by the STRUCTURE program. The high genetic diversity was most probably a consequence of
higher numbers of propagules than outlined by official records of introductions. Use of high number of individuals at stocking is probably the reason for apparently minimized ‘founder effects’ of Nile perch in the introduced ranges. The two underling populations revealed through genetic analysis may be representatives of the two subspecies of Nile perch previously reported in other studies. Implications to the management of this fishery in the East African region is that with the relatively high genetic diversity, the species could be sustainably exploited if it were effectively managed. In addition, further studies of the life histories and other attributes of the two genetic groupings of Nile perch in the region are recommended, as they may require different management plans.
Description
Keywords
Nile perch, East Africa, invasiveness, genetic diversity
Citation
Mwanja, M. T., Mwanja, W. W., Muwanika, V., Masembe, C., & Nyakaana, S. (2012). Genetic evidence of successful establishment of the Nile perch (Lates spp. L.) in East African lakes and implications for management. Management of Biological Invasions, 3(2), 77.http://dx.doi.org/10.3391/mbi.2012.3.2.02