Isoenzyme taxonomy applied on four Species ofCardiumfrom Danish and British waters with a short description of the distribution of the species. (Bivalvia)

Abstract

Replicate experiments, using maleic acid-TRIS-EDTA-MgCl₂ buffer, showed that the four morphospecies, Cardium edule, C. glaucum, C. exiguum, and C. hauniense, corresponded to four different electrophoretic patterns, of which those of C. edule and C. hauniense showed a clear pattern and of C. glaucum and C. exiguum showed tailing electrophoresis. Replicate comparative experiments, using borate buffer, showed that the electrophoretic patterns from samples of C. edule from two different localities were very similar, as were those from C. glaucum from three different localities. We concluded that the four morphospecies were valid species and that there was no tendency towards subspeciation in C. edule or C. glaucum. A short review of the morphology and biology of the species has been included as a background to this study.