Investigation of Genetic Connectivity Among Marine and Freshwater Populations of the Atlantic Stingray (Dasyatis Sabina)

Investigation of Genetic Connectivity Among Marine and Freshwater Populations of the Atlantic Stingray (Dasyatis Sabina)

Alvin Sherman Library 2053

The Atlantic stingray is one of the few elasmobranchs to have conquered freshwater, establishing the only known permanent batoid population in the rivers and lakes of North America. The purpose of this project is to study the breeding and migration patterns of D. sabina over evolutionary time scales. It is hypothesized that the Florida freshwater populations were isolated in the St. Johns river basin when sea level fell during the Pleistocene. A major question we will address is whether marine and fresh water populations have been genetically isolated since that time. We are collecting mitochondrial DNA control region sequences from D. sabina in the following three locations: Florida west coast (Tampa Bay; marine animals), Florida east coast (Melbourne; marine animals), and the St. Johns River basin (fresh water animals). Comparing genetic variation wit hin and among these populations will reveal the population history and allow inferences on the extent of genetic connectivity among D.sabina from these environments. Using PCR protocols developed at NSU’s Oceanographic Center, we have successfully sequenced approximately 720 bases from three individuals from each geographic location. More animals are being sequenced to determine the utility of the chosen locus for population genetic studies. Our results will reveal the extent of genetic diversity present in D. sabina, and also have direct conservation and management applications because this stingray has been targeted as an environmental indicator species for anthropogenic factors in the St. Johns River basin system.