养殖水温对金钱鱼幼鱼耗氧率、排氨率和窒息点的影响

Effects of water temperature on oxygen consumption rate,ammonia excretion rate and asphyxiation point of juvenile Scatophagus argus

【目的】研究不同养殖水温对金钱鱼幼鱼呼吸和代谢活动规律的影响,为其适宜养殖水温的确定提供依据。【方法】采用静水密闭式方法,在盐度5条件下,以体质量(8.84±0.32)g/尾的金钱鱼幼鱼为试验对象,设置15,20,25,30和35℃不同养殖水温处理,测算并分析不同处理金钱鱼幼鱼的耗氧率、排氨率、代谢率、排泄率、氧氮比、呼吸温度系数(Q_(10)值)、排泄Q_(10)值、窒息点及其变化规律,以明确金钱鱼幼鱼适宜的养殖水温。【结果】养殖水温为15~30℃时,金钱鱼幼鱼的耗氧率、排氨率、代谢率和排泄率均随着水温的升高而增加,在30℃时达到峰值,分别为0.46 mg/(g·h)、3.81μg/(g·h)、6.29 J/(g·h)和0.09 J/(g·h),35℃时均开始下降。在15~35℃养殖水温内,金钱鱼幼鱼窒息点随着水温上升而升高,氧氮比为71.76~261.04;呼吸Q_(10)值平均为2.50,20~25℃的呼吸Q_(10)值为1.22;排泄Q_(10)平均为2.23,25~30℃养殖水温的排泄Q_(10)值为1.10。【结论】盐度5条件下,金钱鱼幼鱼主要由碳水化合物和脂肪提供能量,15~30℃为其适宜养殖水温,其中最适养殖水温为20~30℃。

【Objective】The effects of different water temperatures on respiratory metabolism of juvenile Scatophagus argus were investigated to provide evidence for determination of suitable temperature.【Method】Effects of different water temperatures(15,20,25,30 and 35℃)on oxygen consumption rate,ammonia excretion rate,metabolic rate,excretion rate,oxygen nitrogen ratio,respiratory Q_(10),excretory Q_(10) and asphyxiation point of juvenile S.argus at weight of(8.84±0.32)g cultured in low-salt water with salinity of 5 were studied by closed breathing experimental method.【Result】The oxygen consumption rate,ammonia excretion rate,metabolic rate and excretion rate increased with the increase of water temperature in the range of 15-30℃.The peaks at 30℃were 0.46 mg/(g·h),3.81μg/(g·h),6.29 J/(g·h)and 0.09 J/(g·h),respectively.The values began to decrease at 35℃.In the range of 15-35℃,the asphyxiation point increased with the increase of water temperature,and the average oxygen nitrogen ratio(O∶N)at 15-35℃was 71.76-261.04.The average respiratory Q_(10) for all temperatures was 2.50 and the respiratory Q_(10) at 20-25℃was 1.22.The average excretory Q_(10) for all temperatures was 2.23 and the excretory Q_(10) at 25-30℃was 1.10.【Conclusion】Carbohydrates and fats mainly provided energy for juvenile S.argus under salinity of 5.The suitable water temperature was 15-30℃for culturing juvenile S.argus with optimum range of 20-30℃.