746 



Hanunen, C. S. 1971. 



Metabolism of brachiopods and bivalve mollusks. Acta Salamanticensia Serie 

 de Ciencias 36: 471-478. 



Lingulid brachiopods and most mollusks possess succinate oxidoreductases of 

 the type that favor oxidation of succinate, in contrast to most other marine 

 invertebrates. This metabolic adaptation permits these animals to withstand 

 temporary anaerobiosis. Lactate dehydrogenases of all molluscan classes 

 appear to be D-specific. Venus (Mercenaria) mercenaria is not mentioned, but 

 the conclusions apply. - J.L.M. 



747 



Hammen, C. S. 1974. 



Succinate and lactate oxidoreductases of 3 bivalve mollusks. Fed. Proc. 33: 

 403 (abstract 1089) . 



Succinic acid is a major end-product of anaerobic glycolysis in mollusks, 

 lactic acid minor. Extracts of adductor muscle of Mercenaria mereenaria, 

 Mytilus edulis, and Crassostrea virginica were used in oxidoreductase assays. 

 Assay mixtures contained nicotinamide adenine dinucleotide (NAD) or 

 dichlorophenolindophenol (DCIP) . Relations between substrate concentration 

 and reaction velocity were determined for pyruvate reduction (PR) , lactate 

 oxidation (LO) , fumarate reduction (FR), and succinate oxidation (SO) . Results 

 were expressed as apparent Michaelis constants (Km) and maximal velocities 

 (V). Reductase properties varied little: Km of PR 0.54 to 0.61 mM, and Km of 

 FR 25 to 30 mM. Oxidase properties were more varied: Km of LO from Mercenaria 

 twice that of the others, 250 vs 120 mM; Km of SO of Crassostrea 3 to 4 times 

 that of the others, 120 vs 30 and 40 mM. Species varied little in V of 

 oxidases. - J.L.M. 



748 



Hammen, C. S. 1975. 



Succinate and lactate oxidoreductases of bivalve mollusks. Comp. Biochem. 

 Physiol. 50B(3): 407-412. 



Succinic acid is a major end product of anaerobic glycolysis in mollusks, 

 lactic acid minor. Assays were made of adductor muscle extracts of 

 Mercenaria mercenaria, Mytilus edulis, and Crassostrea virginica to test the 

 hypothesis that production of the 2 acids is controlled partially by 

 properties of enzymes catalyzing the final step in each pathway. Reductase 

 properties varied little between species. Apparent Michaelis constants (Km) 

 of pyruvate reduction were 0.54-0.61 mM, K m of fumarate reduction 25-30 mM. 

 Oxidase properties were more varied: K m of lactate oxidation from Mercenaria 

 (250 mM) was twice as great as the other 2 species; K m of succinate oxidation 

 from -Crassostrea 3 to 4 times as great as the others. Mytilus had the 

 greatest maximal velocity for both reductases, but varied little in velocity 

 of oxidases. - modified author's abstract - J.L.M. 



749 



Hammen, C. S. 1979. 



Metabolic rates of marine bivalve molluscs determined by calorimetry. Comp. 

 Biochem. Physiol. 62A(4): 955-959. 



Mercenaria mercenaria mean weight 91.6 g, and at a temp of 21.0°C produced 

 heat at 3.08 J/hr/g wet, and consumed oxygen at 2.68 ymol/hr/g wet. Oxygen 

 consumption rates of Mercenaria vary with pumping rates, which were probably 

 sub-maximal in the animal used, which was confined to a small volume of sea 

 water. - J.L.M. 



209 



