Genetic diversity among the endemic barb Barbodes tumba (Teleostei: Cyprinidae) populations from Mindanao, Philippines

Abstract

Barbodes tumba is an important fishery resource in Lake Lanao and nearby areas in Mindanao, Philippines. It is one of only two remaining endemic cyprinids out of 20 endemic species originally reported in the lake. In this study, specimens were obtained from fishermen and fish vendors from the lake and from three other sites in Mindanao, namely, Nunungan Lake in Lanao del Norte, Dagoyanan Lake in Lanao del Sur, and Pulangi River in Bukidnon. Eighty-seven haplotypes were recovered from the 122 complete mitochondrial DNA control region sequences analysed. All four populations showed high levels of haplotype (0.662–0.976) and nucleotide (0.552–2.736 %) diversities. Pairwise FST values showed high genetic divergence between populations. Maximum likelihood tree and median-joining network showed geographic separation of Bukidnon population from the three other populations. Lanao Lake specimens also formed a distinct group, which clustered with nine specimens from Dagoyanan Lake. All the other specimens from Dagoyanan clustered with specimens from Nunungan Lake. Despite the high intra- and inter-population genetic variation found in the species, its populations need to be protected and managed so that it will not suffer the same fate as that of the other endemic cyprinids which are now reported to be extinct.