Development of microsatellite DNA primers for the giant freshwater stingray, Himantura chaophraya (Batoidea: Dasyatidae) in Thailand, and cross-species amplification in other stingrays

The lack of animal legislation and the threats of overfishing and water pollution jeopardise the existence of the giant freshwater stingray (Himantura chaophraya) in Thailand. Since the information of this species is scarce, a genetic study is useful for raising the issue of conservation on this species. Polymorphic microsatellite loci were isolated and characterised. The number of alleles ranged from 2 to 10 alleles per locus with an average of 6.25 alleles per locus. The observed heterozygosity and expected heterozygosity ranged from 0.2500 to 0.7586 and 0.4129 to 0.8742, respectively. A significant deviation from Hardy-Weinberg equilibrium was observed at some loci. No linkage disequilibrium was observed. Several loci were successfully amplified in other freshwater stingrays.