Genetic comparison of Caspian Sea Rutilus frisii kutum (Kamenskii, 1901) in Gorganroud and Cheshmekile (Tonekabon) rivers using microsatellite markers

The population structure of Rutilus frisii kutum in southern coasts of Caspian Sea was investigated using microsatellite loci. 50 Kutum fish samples were collected from Gorganroud (Golestan province) and Cheshmekile (Mazandaran province) rivers in April 2006. All the 10 loci investigated in this study (Ca1, Ca3, CypG3, CypG24, CypG27, CypG30, Lid1, Rru2, Rru4, Z21908) were polymorphic. The mean number of alleles at the population level was 7.95 which is lower than the reported values for anadromous fishes. Both populations showed signs of bottleneck. The mean value of observed heterozygosity was 0.80 for Gorganroud and 0.74 for Cheshmekile, respectively. Among the 20 tests of population-loci, 11 samples showed significant deviation from Hardy-Weinberg equilibrium. Results from Fst (0.008) and Rst (0.04) values showed low genetic differentiation among the populations, also, AMOVA analysis indicated only 4% genetic diversity between populations. The values of genetic distance was 0.03 among the regions. It seems that mismanagement of kutum’restocking programs has had negative effects on the genetic structure of this species.