Genetic Population Structure of Black Drum in US Waters

Black drum Pogonias cromis is an estuarine dependent saltwater fish that supports important recreational and commercial fisheries throughout its range along US Atlantic and Gulf of Mexico coasts. A previous study examining genetic population structure of black drum, using mitochondrial DNA and limited samples from the Atlantic, reported distinct Gulf of Mexico and Atlantic stocks. The current study uses nuclear microsatellite markers to examine genetic variation of black drum along US Atlantic and Gulf of Mexico coasts. We are testing the hypothesis of the existence of only one population of black drum in US coastal waters, and evaluating genetic population structure along the US Atlantic coast. No microsatellite primers have been developed for black drum, but studies have shown that often primers will amplify confamilial species. Using polymerase chain reaction (PCR) and gel electrophoresis, spotted seatrout Cynoscion nebulosis and red drum Sciaenops ocellatus microsatellite primers were screened for polymorphism and reliable amplification of black drum DNA. Eight polymorphic loci have been identified that will be used to determine genotypes to evaluate genetic population structure. Data from the present study will prove useful for management and conservation of black drum, including accurate definition of geographic stock boundaries to determine appropriate management units.