Molecular population genetic of Persian sturgeon (Acipenser persicus) and stellate sturgeon (Acipenser stellatus) using microsatellite markers

The fishery stocks of most commercial aquatic stocks in the world have shown declining trends in the past two decades. Several factors have been responsible for the decline of stocks the most important of which over fishing and over-exploitation, pollution, loss of natural habitats and natural spawning grounds, construction of dams and bridges across the important rivers which restrict the migratory routes of spawners, decrease in natural reproduction and rehabilitation of stocks through artificial breeding programs. Over-exploitation of stocks and pollution directly affect decreasing stocks in an ecosystem. Not differentiating between different populations and stocks of a species found distributed in an aquatic ecosystem is considered one of the main factors which causes the depletion of stocks in most ecosystems in the world. In most cases this is because genetic variations in aquatic stocks in the wild are not taken into consideration. Six species of sturgeons are found living in the Caspian Sea and its drainage basin which produce more than 85-90% of the world caviar. The Persian sturgeon (Acipenser persicus) and the stellate sturgeon (Acipenser stellatus) are the main sturgeon species of the Caspian Sea. The Persian sturgeon is mainly found in the south Caspian Sea while the stellate sturgeon stocks are considered shared stocks by the five Caspian littoral states. Due to over fishing in the past two decades the legal catch figures for sturgeon stocks in the Caspian Sea dropped from 28500 tons in 1985 to less than 1500 tons in 2004. Similarly caviar production also dropped from 3000 tons to 110 tons in 2005. With regard to the severe reduction in sturgeon stocks it is necessary to take essential steps before these valuable species are totally wiped out. The fisheries management of the five Caspian littoral states should focus their efforts on identifying the different populations and stocks found in the Caspian Sea. Concerted measures should be taken to study the distribution and biomass of the different populations in order to develop a scientific solution for the sustainable use of these endangered species and to secure the long term conservation of sturgeon stocks. The aim of present study was to evaluate the genetic structure of the population of two species Acipenser persicus and Acipenser stellatus and to develop molecular markers to identify and differentiate different populations of these two species.