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

1 Introduction Salinity is an important environmental parameter affecting the growth of the crustaceans, and the toler- ance to salinity varies with species and growth periods. Marsupenaeus japonicus is sensitive to salinity fluctua- tion, and abrupt decrease in salinity can result in high mortality (Chen and Bian, 1994). As reported by Dall (1981), tolerance of the juvenile Metapenaeus bennet- tae, Penaeus esculentus and Fenneropenaeus mer- guiensis to salinity fluctuation is not as strong …

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 (FI) 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).