Effects of salinity on survival, feeding behavior and growth of the juvenile swimming crab, Portunus trituberculatus （Miers, 1876）

• Published in: 中国海洋湖沼学报：英文版 2015 (3), p.679-684
• Main Author: 申屠基康 徐永健 丁张妮
• Format: Article
• Language: English
• Subjects: 三疣梭子蟹; 供给时间; 摄食行为; 生长效果; 盐度; 迈尔; 青少年; 饲料转化率
• ISSN: 0254-4059; 1993-5005

Effect of salinity on survival, feeding behavior and growth of juvenile swimming crab Portunus trituberculatus was investigated under 5 salinity levels of 5, 10, 20, 30 and 40. The results show that the crab juveniles fed 2 or 3 times at the salinity 20 and 30, each lasted for about 25 minutes, for a total feeding time of 73.2±22.65 minutes per day. At these salinities, there were significantly higher in the frequency of feeding and in total feeding time than those at lower salinities of 5 and 10. All crab juveniles moulted when reared at a salinity of 20 during the 5 days duration of the experiment, which is significantly higher than those at other salinities. All juveniles survived at salinity 20, and the survivorship was not significantly different from that at 30, but was significantly higher than those at other salinities. The crab juveniles reared at a salinity of 20 had the highest value of food ration of 0.190 8±0.011 3 g/gBW, average body weight gain of 0.796±0.128 g, gain rate of 87%-96%, and food conversion ratio of 1.20±0.09. There was no significant difference in the values found between 20 and 30 but these values were significantly lower than that at the other salinities （P〉0.05）. Highest activities of digestive enzymes （Amylase, Protease, Lipase） and lowest activities of protective enzymes （SOD, PO, CAT） were also obtained on crab juveniles reared at salinity of 20.