Drastic bottlenecks in the endangered crayfish species Austropotamobius pallipes in Spain and implications for its colonization history

Variation in mitochondrial DNA (mtDNA) was surveyed, using restriction endo nucleases, in the white-clawed crayfish, Austropotamobius pallipes lusitani cus, from 14 populations sampled in Spain. Four additional samples from Fra nce (1), Slovenia (1) and Italy (2) were also analysed. Among the 11 haplot ypes listed, only one was detected from the 154 animals sampled from Spanis h populations. This haplotype was also recorded in the Fosso di Ferfereta p opulation (Italy). Estimates of nucleotide sequence divergence among haplot ypes ranged from 0.45% to 17.4%. Interpopulational genetic relationships sh owed that Spanish populations were closely related to those of Fosso di Fer fereta with a small genetic distance (0.0003) found between them. AMOVA rev ealed that most of the genetic variance (71.97%) was attributed to variatio n between European regions. These results are in accordance with a drastic bottleneck event during the history of the Spanish populations. Four sugges tions, based on human introduction, selection and recent or ancient histori cal events are discussed in relation to the lack of genetic variation in th e Spanish crayfish stock.