Genetic diversity analysis of aquaculture strains of Acipenser stellatus (Pallas, 1771) using DNA markers

Abstract

Acipenser stellatus (stellate sturgeon) that has been intensively captured for decades represents a sturgeon species of great importance for the scientific community and fishermen. Besides overfishing and poaching, their reproduction sites have been destroyed and their natural habitats were affected by pollution. In consequence, wild populations of stellate sturgeon have decreased dramatically and this species is being considered critically endangered. In order to conserve this species, efforts have been made to artificially reproduce native sturgeons and restock natural habitats with the broodstock. The analysis of genetic diversity of the future breeders is of great importance in order to avoid the inbreeding depression and genetic drift. Six aquaculture strains of A. stellatus reared in fish farms from the South of Romania were genetically analyzed. The assessment of the genetic diversity was made by using DNA markers, such as cytochrome b mitochondrial gene and microsatellite nuclear loci. The results showed a moderate genetic variability within the strains and a moderate genetic diversity between the strains. One strain was slightly inbred and is recommended not to be included in the reproduction programs. In conclusion, five out of six aquaculture strains were genetically distinct and can be used in selective breeding programs aimed to conserve stellate sturgeon from the Lower Danube River.