实验对褐牙鲆(Paralichth ys olivaceus)幼鱼在温度胁迫及温度调整后的生长与能量分配进行了研究。驯养于17.5℃的褐牙鲆幼鱼分别在8.5℃(T8.5),13.0℃(T13.0),17.5℃(T17.5),22.0℃(T22.0)和26.5℃(T26.5)养殖10d后,除T22.0处理的褐牙鲆幼鱼除以干重表示时与T17.5和T26.5处理差异不显著外,以湿重、蛋白质和能量表示的鱼体重均显著大于其他处理。所有处理调整养殖温度至22.O℃继续养殖,由于不同温度造成的生长差异在30d内可获得完全补偿。在不同温度养殖期间,摄食量少和分配于生长的能量减少是导致低温处理(T8.5和T18.0)生长慢的主要原因,而Tus和R26.5生长慢的主要原因是分配在生长的能量较少。低温处理分配于生长的能量较少主要是由于其粪便损失和用于呼吸的能量比例较多,而高温处理则主要是由于排泄损失的能量比例较高导致生长能减少。温度调整后的第2个10d,T8.5,T13.0,T17.5和T26.5的摄食量都显著比T22.0多,而温度调整后的30d内不同处理的总摄食量没有显著差异,个体水平上的摄食能在生长、粪便、排泄、呼吸上的分配也没有显著差异。因此,补偿生长的获得主要依靠阶段性的提高摄食量。在温度调整后的30d内,T8.5,8.0和T26.5的幼鱼单位体重日摄食能和生长能都比T22.0多,表现出明显的补偿生长现象。对于整个实验期间而言,T8.5的幼鱼摄食比其他处理少,但由于其排泄和呼吸损失的能量比例较少,因此分配于生长的能量比例比其他处理略多。养殖在不同温度的褐牙鲆幼鱼会在身体蛋白质和能量含量上产生差异,在实验结束时R8.5和T26.5的能量含量与对照组仍有显著差异。本研究的结果表明褐牙鲆幼鱼对温度变动具有较强的适应能力,短期的温度变动不会对其长期生长产生显著影响。
An experiment was conducted to investigate the growth and energy allocation of juv brown flounder, Paralichthys olivaceus during thermal manipulation. During the stress period, enile 17.5 ℃ acclimated juvenile brown flounder were cultured at 8. 5 ℃ (T8.5), 13. 0 ℃ (T13.0), 17. 5 ℃ (T17.5), 22.0 ℃(T22.0), and 26.5 ℃ (T26.5) for 10 d. At the end of the stress period, the fish in T22.0were larger than the other treatments in wet mass, dry mass, protein, and energy content, and except for dry mass, were not significantly different from those in T17.5and Te6.5. The temperature induced growth differences were completely compensated in 30 d after the temperatures were adjusted to 22. 0 ℃. Through the stress period, less feed ingestion and a smaller fraction of energy allocated to growth mainly depressed the growth of fish at low temperatures(T8.5 and T13.0), whereas a smaller fraction of energy al- located to growth accounted for the slow growth in T17.5 and T26. 5. When the fish was kept at low tempera- ture, the energy lost in feces and respiration decreased the energy allocated to growth. Whereas it was the higher proportion of excretion energy that caused less energy being allocated to growth for fish kept at high temperature. During the second 10 d period after temperature adjusting, fish in T8.5, T13.0, T17.5, and T26. 5ingested more feed than T22.0. But no significant difference in ingestion was observed for the whole period after temperature adjusting and the energy allocations among growth, feces, excretion, and respiration show no treatment specific difference. Hence it was concluded that compensatory growth was achieved mainly by short-term increaes in feed intake(hyperphagia). For the whole period after tempera- ture adjusting, the daily unit body weight energy ingestion and growth in T8.5, T13.0, T17.5, and T26.swere significantly higher than in T22.0. Thus the fish exhibited compensatory growth. Through the whole experimental period, fish in T8.5 ingested less feed