Does the Mediterranean killifish Aphanius fasciatus (Teleostei : Cyprinodontidae) fit the one-dimensional stepping-stone model of gene flow?

摘要: Five samples (30 individuals each) of the Mediterranean cyprinodontid fish, Aphanius fasciatus, were analysed by allozyme electrophoresis for a study concerning genetic structure and gene flow among populations. Forty-three loci, twelve which polymorphic at P0.99 level, analysed. A. fasciatus showed low levels polymorphism, with expected heterozygosity values ranging from 0.027 (SE = 0.013) to 0.064 0.023). The modified Rogers' distances ranged 0.053 0.202. observed pattern differentiation populations, obtained multidimensional scaling distances, was consistent geographic distribution. Coancestry coefficient (θ 0.302, SE 0.045) indicated very high degree subdivision populations estimate (the effective number migrants per generation, Nm 0.445), computed Wright's method, restricted regression analysis carried out using log-transformed distance against M^ (pairwise Nm) gave coefficient, b −1.03, indicating that migration rate can occur according one-dimensional stepping-stone model. amount modality in inferred results present are absence dispersal stages fragmented nature brackish-water habitats along coasts.