Temporal stability of genetic diversity revealed by microsatellite markers in restocked populations of Caspian roach, Rutilus caspicus (Yakovlev, 1870)

Rutilus caspicus is considered one of the most important bony fish with high economic value in the Caspian Sea. Since the population size of Caspian roach has decreased during recent decades, restocking of the populations is done through releasing hatchery-produced larvae into the wild. In the present study, the genetic diversity of wild and hatchery populations of R. caspicus was investigated using ten microsatellite loci. Also, microsatellite analysis was performed to compare the population structure of Caspian roach over a time frame of about 11 years. Although the allelic and gene diversity of hatchery populations tended to be lower than those of the wild populations, no significant differences in genetic diversity parameters were observed among the wild and hatchery populations Similar variation levels were noticed among temporal samples of the same population, suggesting temporal stability in the genetic diversity of the wild populations. In most cases, significant departure from the Hardy-Weinberg equilibrium was observed after sequential Bonferroni correction. Results from F-ST analysis showed that a captive hatchery population was the most differentiated group. Also, the UPGMA dendrogram showed that the captive population was the most distant group. The stability of genetic composition between the two periods was noticed by the low and non-significant F(ST )and R-ST estimates. The results from this study are anticipated to provide important information for setting up more efficient strategies for the conservation and restocking of R. caspicus.