Taxonomic implications in conservation management of white-clawed crayfish (Austropotamobius pallipes) (Decapoda, Astacidae) in Northern Italy

Austropotamobius pallipes is a threatened species and a management plan must be put into action in order to avoid its extinction. As part of the recent conservation effort in Northern Italy, a phylogeographic and taxonomic study was deemed necessary. The sequencing of a 464 bp length of 16SmtDNA gene was used. The evolutionary topology and the parsimony network represented a well-structured separation into two clades. The genetic distance between clades was 4.78% (+/-0.71% SD) over the threshold for species distinction for the 16S mtDNA phylogenetic marker. A. pallipes and A. italicus were syntopic in the Po hydrographic basin while A. pallipes was only found in the Northwestern region (Piedmont) and a suture-zone was detected in the Apennine (Scrivia River) and Alpine (Sesia River) affluents. The haplotype and nucleotide diversity showed a similar composition of genetic variability. The phylogeographic findings distinguish two wild population stocks that have to be protected during in situ management decisions. (C) 2004 Published by Elsevier Ltd.