Changes of Oxygen Consumption and Ammonia-n Excretion by Penaeus Chinensis Osbeck at Different Temperature and Salinity Levels

Abstract

Both oxygen consumption (O2 mg/g/h) and ammonia-N excretion (mg/g/h) by juveniles of Penaeus chinensis Osbeck (0.315 ± 0.062 g) were higher at 25°C than at 15°C at salinities of 15, 20, 25, and 30 ppt. At both temperatures (15° and 25°C) measured at 15, 20, 25, and 30 ppt, oxygen consumption was highest at 30 ppt and lowest at 20 ppt. Ammonia-N excretion decreased with increasing salinity from 15-30 ppt at 15° and 25°C. The change in the ratio of oxygen consumed to nitrogen excreted by atom according to the increase of salinity indicated a shift in nutrient utilization from protein-dominated to lipid-dominated metabolism that was more marked at 15°C than at 25°C.