The genetic variation and population structure of narrow-clawed crayfish (Astacus leptodactylus) was examined by means of polymerase chain reaction (PC R) restriction fragment length polymorphism (RF LP) analysis of the cytochrome oxidase subunit I (COI) of mitochondrial DNA. A total of 194 adult specimens were collected from seven sample sites including, two in the south Caspian Sea and one each in Anzali wetland and Aras reservoir and three rivers Chafrood, Masule Rudkhan and S iah Darvishan. The PCR products were digested with 19 restriction enzymes and five enzymes revealed polymorphism patterns (DdeІ, MboІ, TaqI, RsaІ and HinfІ). Twenty eight composite haplotypes were showed with the number of haplotypes in each population sample ranging from 8 to 13. Private haplotypes were found at very low frequencies. Two regional (S iah Darvishan River and Astara) groups were clearly recognized by cluster and molecular variance model (AMOVA) analyses (P<0.0001). Each of these groups revealed dominant haplotypes while these haplotypes play less important rule in population structures of the other geographic areas. Intrapop ulatio n hap lo type (h) and nucleotide (π) diversities were high for each locality, ranging h=0.7560±0.030 and π=0.00334±0.00301, respectively. Results of this study discerned two divergent populations of narrow-clawed crayfish including S iah Darvishan River and Astara. Thus, the population structure of the narrow-clawed crayfish, as inferred from mtDN A analysis, is constituted by genetica lly separate groups that nearly reflect their geographic distribution.
Keywords: Astacus leptodactylus; Genetic diversity; Mitochondrial DN A; PC R-RFLP.