Liu Zhi-Feng, Gao Xiao-Qiang, Yu Jiu-Xiang, Qian Xiao-Ming, Xue Guo-Ping, Zhang Qiao-Yun, Liu Bao-Liang, Hong Lei
Fisheries College, Ocean University of China, Qingdao, 266003, People's Republic of China.
Key Laboratory for Sustainable Development of Marine Fisheries, Ministry of Agriculture, Qingdao Key Laboratory for Marine Fish Breeding and Biotechnology, Yellow Sea Fisheries Research Institute Chinese, Academy of Fishery Sciences, Qingdao, 266071, People's Republic of China.
Fish Physiol Biochem. 2017 Jun;43(3):761-773. doi: 10.1007/s10695-016-0330-3. Epub 2016 Dec 24.
The effects of salinity on survival, growth, special activity of digestive enzymes, nonspecific immune response, and muscle fatty acid composition were evaluated in the American shad (Alosa sapidissima). Juveniles of 35 days after hatching were reared at 0 (control), 7, 14, 21, and 28 ppt for 60 days. At the end of the experiment, juvenile American shad presented higher survival and specific growth rate (SGR) in salinity group (7, 14, and 21 ppt) than control group (P < 0.05). The special activity of trypsin and chymotrypsin was highest in fish reared at 21 ppt, while the highest lipase special activity was obtained in control group (P < 0.05). The special activity of alkaline phosphatase (ALP), lysozyme (LZM), superoxide dismutase (SOD), and catalase (CAT) showed significant increases in salinity group (14 and 21 ppt) compared to control group (P < 0.05). Lower muscle ash contents were detected in salinity group (14, 21, and 28 ppt) than control group (P < 0.05), while the contents of crude lipid and crude protein were significantly higher than control group (P < 0.05). The level of monounsaturated fatty acids (MUFA) exhibited a decreasing trend, while an increased level of polyunsaturated fatty acids (PUFA) was detected with the increase of salinity. Among the PUFA, the content of n-3 fatty acids in muscle tissue was found to be increasing with the increasing salinity, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Results indicate that appropriate increase in salinity was reasonable and beneficial for juvenile American shad culture after a comprehensive consideration, especially salinity range from 14 to 21 ppt.
研究了盐度对美洲河鲱（Alosa sapidissima）存活、生长、消化酶比活力、非特异性免疫反应及肌肉脂肪酸组成的影响。将孵化后35天的幼鱼分别饲养在盐度为0（对照组）、7、14、21和28ppt的环境中60天。实验结束时，盐度组（7、14和21ppt）的美洲河鲱幼鱼存活率和特定生长率（SGR）高于对照组（P<0.05）。胰蛋白酶和糜蛋白酶的比活力在盐度为21ppt的饲养组中最高，而脂肪酶比活力在对照组中最高（P<0.05）。与对照组相比，盐度组（14和21ppt）的碱性磷酸酶（ALP）、溶菌酶（LZM）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）比活力显著升高（P<0.05）。盐度组（14、21和28ppt）肌肉灰分含量低于对照组（P<0.05），而粗脂肪和粗蛋白含量显著高于对照组（P<0.05）。单不饱和脂肪酸（MUFA）水平呈下降趋势，而多不饱和脂肪酸（PUFA）水平随盐度升高而增加。在PUFA中，肌肉组织中n-3脂肪酸含量随盐度升高而增加，尤其是二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）。结果表明，综合考虑后适当提高盐度对美洲河鲱幼鱼养殖是合理且有益的，尤其是盐度范围在14至21ppt之间。
