三种流速对卵形鲳鲹幼鱼耗氧率和排氨率的影响

Effects of the three current velocity on the oxygen consumption and ammonia excretion of Trachinotus ovatus

采用实验生态学方法,研究了饥饿态下平均体重分别为(2.54±1.09)g、(24.35±7.19)g、(233.79±26.00)g、(508.98±126.61)g的卵形鲳鲹幼鱼(Trachinotus ovatus)在静水、0.1 m·s^-1、0.2 m·s^-1三种流速下的耗氧率和排氨率的变化。结果表明,卵形鲳鲹体重对耗氧率和排氨率影响显著(P<0.05)。在同一流速下,耗氧率和排氨率分别随体重的增加而下降,体重与两者间的回归关系符合异速方程Y=aWb。卵形鲳鲹的耗氧率和排氨率随着流速的升高均出现升高的趋势,流速对均重为24.35 g和233.79 g卵形鲳鲹的耗氧率和排氨率影响显著(P<0.05)。在静水条件下,卵形鲳鲹代谢氧氮比的范围为31.36—46.32,表明卵形鲳鲹主要以脂肪和碳水化合物为能源,蛋白质其次。在试验流速范围内,均重为24.35 g卵形鲳鲹幼鱼的氧氮比随着流速的升高而升高,其他两组的氧氮比则随着流速的升高而降低。

The oxygen consumption and ammonia excretion rates of four weight groups(2.54g±1.09 g,24.35g±7.19 g,233.79 g±26.00 g,508.98 g±126.61 g)of starved juvenile golden pompano Trachinotus ovatus were investigated under experimental condition with three different current velocities(0 m·s-1,0.1 m·s-1,0.2 m·s-1).The results showed that body weight had significant influence on the oxygen consumption and ammonia excretion rate(P<0.05)of the fish.Under the same current velocity,both oxygen consumption and ammonia excretion rate of T.ovatus decreased while the body weight increased,and the regressions fitted the allometric equation Y=aWb well.The oxygen consumption and ammonia excretion rate of T.ovatus increased along with the rise of the current velocity,and significant effects were observed in the body weight groups 24.35 g and 233.79 g(P<0.05).The metabolic O(n):N(n)ratio of T.ovatus varied from 31.36 to 46.32 in still water condition.It indicates that T.ovatus uses fat and saccharide as its major metabolic energy source,and protein is the secondary energy source.Under the condition of this study,the metabolic O:N ratio of body weight group 24.35 g increased with current velocity,while the results of the two bigger body weight groups reversed.