Effects of salinity fluctuation in different ranges on the intermolt period and growth of juvenile Fenneropenaeus chinensis

Experiments were conducted to examine the effects of salinity fluctuation on the intermolt period and growth of Fenneropenaeus chinensis with an initial body weight of (0.553 2±0.000 1)g (mean plus or minus SE). The salinity (S₀) of the control treatment is 30throughout the experiment, while the treatments S₂, S₄, S₇ and S₁₀ are subjected to different salinity fluctuations, and the ranges are 2, 4,7 and 10, respectively. After a 30-day feeding trial, the longest and the shortest intermolt periods of the shrimp occur under Treatments S₁₀ and S₂, respectively (difference 37.14%). The special growth rates (SGR) of the shrimp under the five treatments are ranked as S₇ > S₄ > S₂ > S₁₀ > S₀, and the SGR of the shrimp under Treatment S₀ is lower than that under Treatments S₄ and S₇ by 22.36% and 28.11%,respectively (P<0.05). The minimal feed intake (F_I) of the experimental animals occurs in Treatment S₀ (84.04% and 88.54% of that under Treatments S₄ and S₇, respectively) (P<0.05). There are no significant differences in the food conversion efficiency (FCE) of the shrimp under the five treatments (P>0.05)