Effect of salinity on survival and metabolic rate of Charybdis japonica and Portunus trituberculatus

Abstract

Salinity is one of the important factors that determine the survival and distribution of aquatic organisms that have direct effects on the physiological responses of the marine organisms. Metabolic rate measured by oxygen consumption is one of the physiological responses that correlated with environmental change, because it is related to the metabolic activity and energy flow that organisms have to sustain the homeostatic control of mechanisms. The Charybdis japonicus and Portunus trituberculatus are a representative crustacean species along distributed all coastal ecosystems in Korea, which can easily be affected by environmental salinity change. Therefore, the purpose of this study was to determine the effect of salinity on survival and metabolic rate of C. japonicus and P. trituberculatus to assess the physiological response to tolerate salinity changes. The effect of salinity on survival and oxygen consumption rate of C. japonicus (body weight 78.5±4.5 g, mean±SD) and P. trituberculatus (177.9±4.6 g) was investigated at nine different salinities of 33.4 (control), 33.1, 32.8, 32.2, 31.0, 28.7, 23.9, 14.5 and 3.8 psu, respectively. During 96 hr exposure at each salinity, survival were measured daily. Oxygen consumption rate (OCR) was determined at stepwise salinity exposure (33.4→33.1→32.8→32.2→31.0→28.7→23.9→14.5→3.8 psu) with an interval of 24 hr for each salinity. No death of two different crustaceae of the physiological responses that correlated with environmental change, because it is related to the metabolic activity and energy flow that organisms have to sustain the homeostatic control of mechanisms. The Charybdis japonicus and Portunus trituberculatus are a representative crustacean species along distributed all coastal ecosystems in Korea, which can easily be affected by environmental salinity change. Therefore, the purpose of this study was to determine the effect of salinity on survival and metabolic rate of C. japonicus and P. trituberculatus to assess the physiological response to tolerate salinity changes. The effect of salinity on survival and oxygen consumption rate of C. japonicus (body weight 78.5±4.5 g, mean±SD) and P. trituberculatus (177.9±4.6 g) was investigated at nine different salinities of 33.4 (control), 33.1, 32.8, 32.2, 31.0, 28.7, 23.9, 14.5 and 3.8 psu, respectively. During 96 hr exposure at each salinity, survival were measured daily. Oxygen consumption rate (OCR) was determined at stepwise salinity exposure (33.4→33.1→32.8→32.2→31.0→28.7→23.9→14.5→3.8 psu) with an interval of 24 hr for each salinity. No death of two different crustacea