人工饲养条件下额外投喂海蜇对银鲳生长及代谢酶活性的影响

Effects of extra feeding of Rhopilema esculentum on growth and activities of metabolic enzymes of juvenile Pampus argenteus under artificial feeding conditions

以银鲳(Pampus argenteus)为研究对象,进行了5组不同频率额外投喂海蜇(Rhopilema esculentum)的实验,依次为无额外投喂海蜇组(对照组)、1次/d、1次/3 d、1次/6 d和1次/12 d(依次标记为O组、A组、B组、C组和D组),通过分析实验中期(36 d)和实验结束时(60 d)银鲳的生长情况及其不同组织中主要蛋白与脂类代谢相关酶活性的变化,揭示银鲳在额外投喂海蜇过程中,其生长、机体蛋白和脂类代谢指标的变化。结果显示,36 d和60 d时,高频率额外投喂海蜇组(A组和B组)银鲳增重率和特定生长率显著高于D组,但与对照组无显著差异(P>0.05);各组血清和肝脏中谷丙转氨酶(GPT)和谷草转氨酶(GOT)活性均无显著差异(P>0.05);60 d时,A组血清脂蛋白酯酶(LPL)活性显著高于其它各组,各组间肝脏与肌肉中LPL活性无显著性差异;60 d时,高频率组(A组和B组)肝脏脂肪酸合成酶(FAS)活性显著高于低投喂频率组(C组和D组)(P<0.05),肌肉组织中,额外投喂海蜇试验组FAS活性均显著高于对照组。结果表明,高频率投喂海蜇可提高银鲳组织代谢酶的活性,特别是脂代谢相关酶的活性,从而促进机体对营养物质的消化吸收,在一定程度上提高银鲳的生长率,在银鲳人工养殖过程中,基于机体代谢指标的分析,每3天额外投喂一次海蜇较为适宜。

Silver pomfret（ Pampus argenteus）,distributed in saline waters along China ＇s coast from the Yellow Sea to the South China Seas,is rich in nutrition,and is one of the main species in Chinese fishery.Jellyfish is sometimes considered as valueless,although they are important food sources for silver pomfret.Currently,there are extensive researches of silver pomfret and jellyfish respectively focusing on the biology,nutrition,ecology and ethology. Studies on extra feeding of jellyfish to silver pomfret under artificial feeding conditions are still relatively rare. In this study,we conducted 5 treatments,including a control group with no extra feeding of jellyfish and 4 treatments with extra feeding of jellyfish（ about 10% of silver pomfret weight）every 1（ A）,3（ B）,6（ C） and 12（ D） days,to analyze the changes of growth and activities of major protein metabolic enzymes [glutamic-pyruvic transaminase（ GPT）,glutamic-oxalacetic transaminase（ GOT）and glutamate dehydrogenase（ GDH） ]and lipid metabolic enzymes [lipoprotein lipase（ LPL） and fatty acid synthetase（ FAS） ] after 36 days and 60 days respectively. During the experiment,silver pomfret was fed daily with self-made gruel diet. The water was maintained at 25-32℃ and a half volume of water was changed per day. The main results were as follows： After 36 and 60 days of experiment,the weight gain rate（ WGR） and specific growth rate（ SGR） of high-frequency groups（ A and B） were higher than those of lowfrequency groups（ C and D） and the control group,and the WGR and SGR of group A and B were significantly higher than those of group D（ P〈0. 05）,but no significant difference with the control group.The GPT and GOD activities in liver of high-frequency groups were higher than those of low-frequency groups and the control group,but no significant difference was found in GPT and GOD activities of serum and liver with extra feeding of jellyfish（ P〉0. 05）. Comparison with the liver GDH activities of the control group and low-frequency groups,high-frequency groups showed an increasing tendency. The LPL activities of group A were significantly higher than those of the other groups in serum（ P〈0. 05） after 60 days of experiment. In liver and muscle,there was no significant difference among LPL activities of each group（ P〉0. 05）. At the end of the experiment,the FAS activities of high-frequency groups were significantly higher than those of lowfrequency groups in the liver（ P〈0. 05）. In the muscle,the FAS activities of 4 treatments with extra feeding of jellyfish were significantly higher than those of the control group（ P〈0. 05）. In conclusion,under these experimental conditions,extra feeding of jellyfish could increase the activities of protein and lipid metabolism related enzymes,especially the lipid metabolism related enzymes,improve the digestion and absorption of nutritious of silver pomfret,so to improve the growth of silver pomfret to some extent. The optimum frequency of extra feeding of jellyfish in the process of raising silver pomfret is every three days,based on the analysis of the activities of metabolic enzymes.