Lin L Y, Weng C F, Hwang P P
Institute of Fisheries Science, National Taiwan University, Taipei, Taiwan, Republic of China.
Physiol Biochem Zool. 2001 Mar-Apr;74(2):171-7. doi: 10.1086/319670.
Euryhaline tilapia larvae are capable of adapting to environmental salinity changes even when transferred from freshwater (FW) to seawater (SW) or vice versa. In this study, the water balance of developing tilapia larvae (Oreochromis mossambicus) adapted to FW or SW was compared, and the short-term regulation of drinking rate of the larvae during salinity adaptation was also examined. Following development, wet weight and water content of both SW- and FW-adapted larvae increased gradually, while the dry weight of both group larvae showed a slow but significant decline. On the other hand, the drinking rate of SW-adapted larvae was four- to ninefold higher than that of FW-adapted larvae from day 2 to day 5 after hatching. During acute salinity challenges, tilapia larvae reacted profoundly in drinking rate, that is, increased or decreased drinking rate within several hours while facing hypertonic or hypotonic challenges, to maintain their constancy of body fluid. This rapid regulation in water balance upon salinity challenges may be critical for the development and survival of developing larvae.
广盐性罗非鱼幼鱼即使从淡水（FW）转移到海水（SW）或反之亦然，也能够适应环境盐度变化。在本研究中，比较了适应淡水或海水的发育中的罗非鱼幼鱼（莫桑比克罗非鱼）的水平衡，并研究了幼鱼在盐度适应过程中饮水速率的短期调节。发育后，适应海水和淡水的幼鱼的湿重和含水量均逐渐增加，而两组幼鱼的干重均呈缓慢但显著的下降。另一方面，孵化后第2天至第5天，适应海水的幼鱼的饮水速率比适应淡水的幼鱼高4至9倍。在急性盐度挑战期间，罗非鱼幼鱼的饮水速率反应强烈，即在面对高渗或低渗挑战时，在数小时内饮水速率增加或降低，以维持其体液的恒定。盐度挑战时这种水平衡的快速调节可能对发育中幼鱼的发育和生存至关重要。
