Muscle nitrogen metabolism of freshwater crab, Oziotelphusa senex senex Fabricius, during acute and chronic sumithion intoxication.

Muscle nitrogen metabolism was studied in the crab, Oziotelphusa senex senex Fabricius, following acute (1 day) and chronic (20 days) exposure to 0.1 ppm sumithion solution. Proteolysis in the muscle tissue in acute exposure was increased after exposure for 24 h. The muscle tissue of chronically exposed crabs seemed to develop a more efficient mechanism for the detoxication of ammonia compared with that of acutely exposed crabs. The survival of crabs after chronic sumithion intoxication has been attributed to adaptive changes involving protein synthesis and the metabolism of ammonia.