WILLIAM J. KAREL, ROCKY WARD, AND IVONNE R. BLANDON, Coastal Fisheries Division, Perry R. Bass Marine Fisheries Research Station, Texas Parks and Wildlife Department, HC 02 Box 385, Palacios, Texas 77465, USA

Protein electrophoresis was utilized to survey nuclear genetic variation and population structure of black drum from multiple bays along the Texas coast. Levels of genetic variability were found to be similar or slightly higher than those previously reported for Texas sciaenids. Black drum exhibited nonrandom distribution of alleles both within and between bays. Estimates of gene flow between bay systems indicated absolute population subdivision was limited. Genetic similarity between populations was relatively high but distance metrics indicated some genetic differentiation. The significance of such genetic variation and the potential management implications of these findings will be considered.