Correlations between Enzyme Profiles in Cephalopod Muscle and Swimming Behavior

Abstract

The maximum activities of octopine dehydrogenase, lactate dehydrogenase, alanopine dehydrogenase, citrate synthetase, a-glycerophosphate dehydrogenase, malate dehydrogenase, and glutamate oxaloacetate transaminase were measured in a range of muscles used in swimming by octopods, squids, cuttlefishes, and a nautiloid. The high activities of octopine dehydrogenase and the positive correlation between the activities of Krebs cycle enzymes and enzymes used in the cytoplasmic reoxidation of NADH during aerobic glycolysis indicate the importance of carbohydrates as a major fuel during both anaerobic and aerobic muscle work. The maximum activities of enzymes associated with anaerobic and aerobic carbohydrate catabolism correlate well with the ways in which cephalopod muscles are used in providing propulsion during swimming.