Abstract Rearing winter flounder (Pseudopleuronectes americanus) in captivity for aquaculture and stock enhancement is a viable option to relieve fishing pressure and aid in ongoing recovery strategies. The objective of this study was to determine the effect of photoperiod on growth and survival of young-of-the-year juvenile winter flounder. Juveniles were reared for 12 weeks at three photoperiods: 24 light/0 dark, 18 light/6 dark, and 12 light/12 dark. Twenty fish were stocked into each of 18 enclosures with six enclosures per treatment. Fish in all treatments were fed to satiation every four hours. All fish were imaged at stocking and at three-week intervals. Growth was measured as changes in standard length (SL) and body area (BA). As early as Week 3, fish in all treatments were significantly different in terms of SL and BA. In general, fish grown under continuous 24 light were the largest and fish in the 12 light/12 dark regime were the smallest. Maximum specific growth rates of 0.41 % per day for SL and 0.83 % per day for BA were achieved in the 24 light/0 dark photoperiod. Average mortality rate over the course of the experiment was 9.17 % and there were no significant differences in the number of dead fish among the treatments. In conclusion, this study demonstrates that a longer day coupled with available food will increase growth rate for winter flounder juveniles, without affecting survival. By extending the photoperiod, growth in young-of-the year winter flounder is accelerated, bringing the growth rate of winter flounder close to that of other commercially produced flatfish.

中文翻译：

---

延长光周期提高孵化场饲养的右眼比目鱼的生长性能

摘要 圈养冬季比目鱼 (Pseudopleuronectes americanus) 用于水产养殖和种群增殖是缓解捕捞压力和帮助持续恢复战略的可行选择。本研究的目的是确定光周期对幼年冬季比目鱼生长和存活的影响。幼鱼在三个光周期下饲养 12 周：24 光/0 暗、18 光/6 暗和12 光/12 暗。20 条鱼被放养到 18 个围栏的每一个中，每次处理六个围栏。所有处理中的鱼每四小时喂一次饱。所有的鱼都在放养时和每隔三周拍摄一次。生长被测量为标准长度 (SL) 和身体面积 (BA) 的变化。早在第 3 周，所有处理中的鱼在 SL 和 BA 方面都存在显着差异。一般来说，在连续 24 光条件下生长的鱼最大，在 12 光/12 暗条件下生长的鱼最小。在 24 光/0 暗光周期中，SL 的最大比增长率为每天 0.41%，BA 为每天 0.83%。实验过程中的平均死亡率为 9.17%，处理之间的死鱼数量没有显着差异。总之，这项研究表明，更长的一天加上可用的食物将提高冬季比目鱼幼鱼的生长速度，而不会影响存活率。通过延长光周期，幼年越冬比目鱼的生长速度加快，使越冬比目鱼的生长速度接近其他商业生产的比目鱼。