温度和盐度对云纹石斑鱼早期幼鱼生长和存活的影响

Effects of Temperature and Salinity on the Growth and Survivability of Young Epinephelus moara

采用突变和渐变两种方法初步探讨了温度和盐度的改变对云纹石斑鱼早期幼鱼的生长和存活的影响．研究显示：云纹石斑鱼早期幼鱼适宜生长存活在盐度范围14—40psu内，最适生长盐度范围为14～19psu．云纹石斑鱼早期幼鱼适宜温度范围为21～30℃．温度实验中，在18℃以下的水中，幼鱼摄食能力减弱，活力低下，导致抵抗力下降，易感染病原菌；在高于33℃的水中，幼鱼运动过频，导致消耗大量能量，抑制生长．研究结果表明：云纹石斑鱼幼鱼对盐度具有较强的耐受能力，适当降低盐度有益于提高其生长速度，且幼鱼对温度的要求比较严格．

The present study evaluates the effects of temperature and salinity on growth and survival of early young Epinephelus moara by changing water temperature and salinity gradually or suddenly. The results of this study showed that the young fish were able to survive in a salinity range of 14 - 40 psu （ practical salini- ty unit）. The optimal salinity range for grow of young fish was 14 - 19 psu. The suitable water temperature range is 21 -30 ℃. The fish was less active and ate less with temperature of water lower than 18 ℃ that re- duced resistance of fish and made them more vulnerable to pathogenic bacteria. The fish was hyperactive with temperature of water higher than 33 ℃ that exhausted more energy and inhibited growth of fish. The results in- dicated that the young fish was able to tolerance the changing of salinity, and by reducing salinity appropriately could improve the growth rate of fish. The young fish is sensitive to temperature change.