Amplified Fragment Length Polymorphism markers reveal population structuring in <i>Dimidiochromis kiwinge</i> (Teleostei: Cichlidae), a commercially-exploited species from Lake Malawi

Abstract

The understanding of between- and within-population genetic variation and its partitioning on the basis of geographic origin is crucial in designing efficient fishing and conservation strategies of populations and/or species. However, for Lake Malawi's cichlid species, such population genetic studies are hampered by a large amount of genetic variation being shared among populations. To circumvent this problem, it is necessary to use highly polymorphic molecular markers. In this study, Amplified Fragment Length Polymorphism (AFLP) markers were used to assess the genetic diversity within, and among, Dimidiochromis kiwinge populations. AFLP analysis generated a total of 686 bands across all populations, of which 625 (91.1%) were polymorphic. AMOVA (Analysis of Molecular Variance) revealed significant genetic variation, the majority of which (78.7%) resided within populations. All but one of the pairwise fixation indices were significantly different from zero, suggesting limited or no gene flow among populations (overall F_st = 0.2135). Such limited gene flow among populations has vital implications for the management and conservation of this important food resource.

Keywords: cichlids, conservation, fisheries, gene flow, genetic diversity, population structuring

African Journal of Aquatic Science 2007, 32(1): 39–44