低盐度胁迫不同时间对褐牙鲆幼鱼生长的影响

将驯养于海水盐度为19的褐牙鲆（Paralichthys olivaceus）幼鱼放入盐度为5的海水中胁迫0周（对照）、1周、2周、3周和4周后，立即将海水盐度调节至19，养殖到第10周，观察幼鱼的生长情况。研究发现，低盐度海水养殖的褐牙鲆幼鱼体质量仅在低盐胁迫的第1周内显著小于对照组，不同处理的日生长系数在第3周与第5周呈现显著性差异，其余时间阶段内不同处理的体质量和日生长系数未见显著差异。胁迫阶段褐牙鲆幼鱼摄食率整体上略低于对照处理，但恢复阶段摄食率未出现大于对照处理的一致趋势。整个试验期间经低盐度处理的褐牙鲆幼鱼饲料转化效率略大于对照处理。试验结果显示，低盐度5对褐牙鲆幼鱼的生长没有产生长期影响，也不能通过较长时间的低盐度养殖引起褐牙鲆幼鱼的补偿生长效应。

Effects of low salinity stress on growth of juvenile Paralichthys olivaceus

To investigate the growth of juvenile brown flounder （Paralichthys olivaceus） under low salinity stress, we cultured the juveniles at salinity 5 for 0 week （control） , 1 week, 2 weeks, 3 weeks and 4 weeks, respectively, and then changed the salinity to 19 immediately. The experiment last 10 weeks. It is found that the average body weight of the juveniles at low salinity is significantly smaller than that in the control only in 1^st week. Significant difference in daily growth coefficient among different treatments is found in 3^nd and 5th week. There is no significant difference in the body weight and daily growth coefficient during the other experimental periods. The feeding rate of the juveniles under low salinity stress is slightly lower than that in the control. However, in recovery periods, no higher feeding rate is ohserved at low salinity. During the whole experimental period, the average feed conversion efficiency of the juveniles at low salinity is slightly higher than that in the control. The results indicate that low salinity （5） imposes no long-term effects on the growth of juvenile brown flounder and compensatory growth can not be achieved by culturing the flounder at low salinity for a long period.