ELECTROPHORETIC VARIATION IN SYMPATRIC MUD CRABS FROM NORTH INLET, SOUTH CAROLINA

¹ Department of Biology, Clark University, Worcester, Masschusetts 01610

The genetic variation of 27 scorable genes in Eurypanopeus depressus, 25 in Panopeus herbstii form "simpsoni" and 24 in P. herbstii form "obesa" at Town Creek, North Inlet, South Carolina, was studied by gel electrophoresis. The three populations had low levels of genetic variability, comparable to those found in other decapod crustaceans, with polymorphisms observed only at the amylase and malate dehydrogenase loci. The two forms of P. herbstii could be distinguished both by previously described morphological differences and by genetic differences found in this study. The amounts of genetic variation in E. depressus and P. herbstii were similar, as measured by H, but shared electromorphs at only 4 of 23 scorable loci. The common, but specific, polymorphisms at amylase and malate dehydrogenase were taken to imply selective influences as a factor in their maintenance within these two sympatric genera.