GENETIC AND MORPHOLOGICAL SYSTEMATIC STUDIES ON THE CRAYFISH AUSTROPOTAMOBIUS-PALLIPES (DECAPODA, ASTACIDAE)

Morphological criteria and mitochondrial DNA (mtDNA) were analyzed to examine the taxonomic and systematic relationships of the endangered c rayfish species Austropotamobius pallipes. Morphological data confirme d the difficulty of differentiating the 3 subspecies: A. p, pallipes, A. p. italicus, and A. p, lusitanicus. MtDNA analysis by RFLP using 6 endonucleases revealed 5 haplotypes and allowed unequivocal identifica tion of tie subspecies. The nucleotide sequence divergence among haplo types characteristic of each subspecies ranged from 10.93-13.6% and ma y be explained by an ancient geographical separation of each subspecie s. This distribution of genetic variation agrees with the presumption of 3 refugial regions during the glaciation periods, possibly the Iber ian Peninsula, southern France, and the Balkans. UPGMA analysis from n ucleotide distances placed A. p. italicus and A. p. lusitanicus in a c luster separate from A. p. pallipes, suggesting that A. p. italicus an d A. p. lusitanicus are more closely related.