水流速度对黑鲷和美国红鱼续航游泳能力及生理代谢的影响

SUSTAINED SWIMMING ON THE ENDURANCE TIME AND PHYSIOLOGICAL METABOLISM OF ACANTHOPAGRUS SCHLEGELI AND SCIAENOPS OCELLATUS

为了确保黑鲷(Acanthopagrus schlegeli)和美国红鱼(Sciaenops ocellatus)在开放海域的养殖产量和鱼类养殖福利,在20℃下,对体长差异性不显著(P>0.05)的两种鱼进行续航游泳能力测试。首先,确定不同流速下的耐力游泳时间,然后选择耐力游泳时间为150min时的速度进行续航游泳实验。其中黑鲷和美国红鱼分别被迫以3.15和4.32 BL/s的恒定游泳速度,进行0、30min、60min、90min、120min和150min的测试,解剖鱼获得肌肉、血液和肝脏,测定样品在6个时间点的代谢物浓度,每个时间点保证3组有效数据。对0和150min的实验组对比,结果显示,两种鱼肝糖原、背肌乳酸和血糖浓度差异显著(P<0.05),肌肉糖原浓度差异不显著(P>0.05)。双变量相关分析显示,随着疲劳程度增加,肝糖原浓度下降,背肌乳酸和血糖上升。灰度关联分析和主成分分析显示,血糖和肝糖原浓度是影响疲劳的主要因素,但黑鲷相比美国红鱼,其浓度变化范围更大。综上:(1)美国红鱼比黑鲷拥有更强的游泳能力,而且黑鲷和美国红鱼不适合养殖在流速超过3.15和4.32 BL/s的环境中;(2)肝糖原浓度是限制两种鱼续航游泳能力的关键因素,实验结果为其他鱼类游泳和代谢的研究提供参考。

It has become possible to set up deep-water cages in the open ocean in response to the further development of the marine aquaculture industry.In these conditions,fish encounter strong currents and waves,and ensuring their wellness becomes a crucial part of the farming process,so studying the endurance of farmed fish species is necessary.However,there are few studies on the ability of fish to swim continuously in constant current mode.Breeding of black snapper and American redfish is currently expanding into more open waters,so its endurance swimming ability needs to be assessed to ensure farmed yields and fish farming welfare.At 20℃,we tested the endurance swimming ability of two fish with no significant differences in body length(P>0.05).First,determine the endurance swimming time at different flow rates,and then choose the speed when the endurance swimming time is 150min to carry out the endurance swimming experiment.Black snapper and American redfish were tested for 0,30min,60min,90min,120min and 150min at constant swimming speeds of 3.15 and 4.32 BL/s,respectively.Measure the concentrations of metabolites in the muscle,blood,and liver of the fish at six-time points,ensuring that each time point produces three sets of valid data.At 0 and 150min,the concentrations of fish liver glycogen,back muscle lactic acid,and blood glucose were significantly different between the experimental groups(P<0.05),but the concentrations of muscle glycogen was not(P>0.05).A bivariate correlation analysis revealed that liver glycogen concentration decreased and dorsal muscle lactate and blood glucose increased with increasing fatigue.Gray-scale correlation analysis and principal component analysis showed that blood glucose and liver glycogen concentrations were the main factors affecting fatigue.However,the concentration range of black sea bream was larger than that of American redfish.Our experimental results concluded that:(1)American redfish have stronger swimming abilities than black snapper,and black snapper and American redfish are unsuitable for culture at flow rates exceeding 3.15 and 4.32 BL/s,respectively.(2)Liver glycogen concentration limits the endurance swimming ability of both fishes,and the results also provide a reference for the study on swimming and metabolism in other fishes.