Molecular phylogeny of diploid Bulinus sp. (Gastropoda: Planorbidae) populations in Cameroon crater lakes.

Bulinus sp. (2n=36) is a diploid freshwater snail found in Cameroon crater lakes; it belongs to a group of medically important freshwater snails. Some members (Bulinus truncatus, Bulinus tropicus) of this group had been reported to be involved in the transmission of parasites (Schistosoma sp. and Calicophoron microbothrium) to human and livestock in tropical Africa. Yet, understanding of the evolutionary identity of the diploid snail such as its phylogenetic position and the genetic divergence among populations, remains limited. In this study, we constructed the molecular phylogeny of Bulinus sp. using sequences of mitochondrial cytochrome oxydase subunit 1 (CO-1, 365 nucleotides). Partial sequences of CO-1 were obtained and genetic divergences between populations estimated after the alignment of 365 nucleotides from each studied population. The lack of deep molecular divergences between populations of Bulinus sp. from western Cameroon crater lakes may indicate that they belong to the same lineage; therefore, it implies that diploid B. truncatus/tropicus complex snail-like in Cameroon share a common ancestor. The CO-1 of the three studied populations of Bulinus sp., clustered together with other diploid pan-African representatives of the B. truncatus/tropicus complex, showed little evidence of genetic similarities.