Genetic structure of the invasive Nile tilapia Oreochromis niloticus (Perciformes, Cichlidae) and molecular identification of tilapia species in Panama using barcode

Abstract

Genetic diversity and genetic structure of the invasive Nile tilapia (Oreochromis niloticus) were studied using partial sequences of cytochrome oxidase I gene from samples collected in Gatun, Bayano, Alajuela, and Barrigon lakes, Republic of Panama. O. niloticus sequences from Bayano included in the analysis corresponded to samples from previous studies conducted in this lake. O. niloticus showed low genetic diversity (π = 0.00010, Hd = 0.059) and exhibited only two haplotypes. Haplotype 1 was common in all areas whilst, haplotype 2 was present uniquely in Bayano Lake. Pairwise FST and AMOVA results showed reduced genetic differentiation among areas (FST = 0.07 and percentage of variation between populations of 7.76% respectively). Reduced values of genetic diversity and absence of genetic differentiation among locations suggest the existence of a single population for O. niloticus. This research also provides the first molecular list for other four tilapia species (O. mossambicus, O. aureus, O. urolepis and Coptodon rendalli) and one molecular hybrid (O. niloticus x O. aureus) reported in Panama. This information will allow managers to trace local demos of O. niloticus and other invasive species populations along Panama and Central America.