Mitochondrial DNA variation and population genetic structure of the white-clawed crayfish, Austropotamobius pallipes pallipes

Here we report a high level of mtDNA variation from RFLP analysis within A. p. pallipes from 21 French and 4 British populations. Seventeen haplotypes were recorded among 269 individuals. Nucleotide sequence divergence (p) among mtDNA haplotypes ranged from 0.0019 to 0.0425. Nucleotide diversity (π) ranged from 0.01 to 0.006 (mean = 0.0031) and from O to 0.001 (mean = 0.00037) for populations located in southern and northern France, respectively. Graphical representation from principal coordinate analysis based on Nei's genetic distance values among populations showed two groups, cluster A, including the 16 populations sampled in the north-western and north-eastern France, England and Wales and cluster B containing 9 populations sampled in the central and southern France. No genetic differences were noted among the most northern French and English populations whereas marked interpopulation genetic diversity was observed in southern populations. Such genetic heterogeneity among populations of A. p. pallipes appears to be related to habitat fragmentation and subsequent recolonizations from refugial areas during the Pleistocene. Implications for the conservation of A. p. pallipes are discussed.