Succinate dehydrogenase in various tissues of Anodonta couperiana, Elliptio buckleyi and Mercenaria campechiensis (Mollusca: Bivalvia).

The specific activities, kinetic constants and pH optima for succinate dehydrogenase were determined in mantle, gill and adductor muscle from three bivalves (Anodonta couperiana, Elliptio buckleyi and Mercenaria campechiensis). In general the Km values for succinate and Ki values for fumarate differed in all bivalve tissues whereas the Ki for malonate was consistently low. The ratio of Ki (fumarate) to Km (succinate) was less than one for all tissues studied. This is similar to many facultative anaerobes with fumarate reductase activity.