Physiological and biochemical responses of Dosinia corrugata to different thermal and salinity stressors

Temperature and salinity are major factors affecting geographic distribution, reproduction, and physiological processes of marine and estuarine organisms. In this study, the effects of different temperatures and salinity on the respiratory metabolism and physiological response were evaluated in D.corrugata by measuring oxygen consumption rate (OCR), ammonia excretion rate (AER), and glycolytic enzyme activity. An increase in the OCR of D.corrugata with increasing temperature was observed. No peak of oxygen consumption was observed in D.corrugata over the temperature range evaluated. There was an increase in AERs with increasing temperature and salinity, respectively. With increasing salinity, the enzyme activity increased until it reached a peak at a salinity of 30ppt, while the highest HK and LDH activity was observed at a salinity of 25ppt. Our results may be used to optimize the temperature and salinity conditions for optimal growth and survival of D.corrugata and to provide basic information for conservation management and fishing moratorium of this economically important bivalve species. The enzyme activity decreased slightly from 15 to 20 degrees C, but when the temperature exceeded 20 degrees C, enzyme activity increased, reaching a maximum at 30 degrees C (tested range of 10-30 degrees C). With increasing salinity, the enzyme activity increased until it reached a peak at a salinity of 30ppt, but once the salinity was greater than 30ppt, the enzyme activity began to decrease up to salinity of 35ppt.