Oxygen Consumption, Ammonia Excretion and Suffocation Point in Mugil cephalus Juvenile
Author of the article:LI Jiaer1, CAO Shouhua1,2, OU Youjun1, LIU Rujian1,2, ZHANG Jiansheng3
Author's Workplace：(1. Key Laboratory for Exploitation & Utilization of Marine Fisheries Resource in South China Sea, Ministry of Agriculture; South China Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; 2. College of Fisheries and Life，Shanghai Ocean University, Shanghai 201306, China; 3. Guangdong Raopign Well-bred Pomadasids Fish Farm, Raoping, Guangdong Province 515723, China)
Key Words：Mugil cephalus; juvenile; oxygen consumption rate; ammonia excretion rate; suffocation point
Abstract： The effects of body weight, illumination, stocking density, water velocity and diurnal variation on oxygen consumption rate and ammonia excretion rate of Mugil cephalus juvenile were determined by closed flow experimental methods, and suffocation point and suffocation time in relation to body weight were investigated in this study. Mugil cephalus juvenile were stocked in the conditions with water temperature at 19℃±1℃，salinity at 30 and pH at 7.7. The result showed that the oxygen consumption rate of Mugil cephalus juvenile were increased along with body weight which could be expressed by power equation Y= 0.4759X0.1878 (R2=0.9454). Illumination had significant effect on the oxygen consumption rate rather than ammonia excretion rate. Stocking density had significant influence on oxygen consumption rate (P<0.05) and ammonia excretion rate (P<0.01). Respiratory metabolism of Mugil cephalus juvenile was active during the time from 11:00 to 23:00. Effect of water velocity was significant on both oxygen consumption rate and ammonia excretion rate (P<0.01). Weight had a great effect on suffocation point and suffocation time (P<0.01).