Genetic Parentage Analysis of Red Drum in South Carolina and the Use of Genotypic Data from Archived Otoliths

The red drum Sciaenops ocellatus is an estuarine-dependent fish that is the focus of a large recreational fishery along the U.S. Atlantic coast and in the Gulf of Mexico. In response to dramatic declines in juvenile abundance, the South Carolina Department of Natural Resources has been experimentally stocking local estuaries since the late 1980s. Here we report on the genetic parentage approach that has been employed to identify fish of hatchery origin through DNA isolated from fin clips collected from wild-caught fish. In some cases tissue samples were not available, making it necessary to find an alternative source of DNA. Thus, we also examined the use of archived otoliths as a source of genetic material for parentage analysis. Amplification resulted front 96% of the extractions obtained from the extracellular tissue remaining on otoliths. In comparison with extractions obtained from fin clips, otoliths appear to be a reliable DNA source. These results not only present a method for nonlethally identifying hatchery fish but also offer a unique opportunity for fisheries researchers to utilize the archived otoliths typically collected and stored for age and growth studies. As a source of DNA, archived otoliths can be used for a wide variety of applications, including the provision of historical context for the genetic diversity of current fish populations.