不同规格绿鳍马面鲀耗氧率、排氨率与窒息点研究

Study on oxygen consumption rate,ammonia emission rate and asphyxia point of different sizes of Thamnaconus septentrionalis

为研究鱼体大小对绿鳍马面鲀耗氧率、排氨率以及窒息点的影响,利用静水封闭式呼吸室法,在水温22℃、盐度30条件下,测定了4种规格[体质量分别为(21.51±4.78)、(44.55±3.18)、(76.98±7.33)、(153.79±4.99)g]绿鳍马面鲀的耗氧率、排氨率和窒息点。结果显示,绿鳍马面鲀的耗氧率和排氨率均随着鱼体规格的增大呈现逐渐降低的趋势,且各组间的耗氧率均存在显著性差异(P<0.05);绿鳍马面鲀的窒息点随着鱼体规格的增大而提高,规格最小的试验鱼,其窒息点最低,且与规格较大的2个组有显著性差异(P<0.05),其余3组之间则差异不显著(P>0.05);试验测得的氧氮比为6.27~18.53,表明在试验条件下绿鳍马面鲀主要的供能物质为蛋白质。试验结果表明,鱼体大小对绿鳍马面鲀的耗氧率、排氨率均有显著影响,但对其窒息点的影响不显著。

To study the effects of fish body size on breath and metabolic status of Thamnaconus septentrionalis,the oxygen consumption rate,ammonia excretion rate and asphyxia point of T. septentrionalis with different sizes[(21. 51±4. 78),(44. 55±3. 18),(76. 98±7. 33) and (153. 79±4. 99) g] were determined by still water closedbreathing chamber method. The results showed that the oxygen consumption rate and ammonia excretion rate of T.septentrionalis significantly decreased with fish size increasing(P<0. 05). The asphyxia points of T. septentrionalisincreased with the increase of fish body size,and the lowest level was observed in (21. 51±4. 78) g group(P<0. 05),while there was no significant difference among other groups(P >0. 05). The oxygen-nitrogen ratio was6. 27~18. 53,indicating that the main energy supply substance of T. septentrionalis under the test conditions wasprotein. The results showed that the fish body size had a significant effect on the oxygen consumption rate andammonia excretion rate of T. septentrionalis,but had no significant effect on the asphyxia point.