北方须鳅仔稚鱼发育观察及饥饿不可逆点的确定  

Observation of Larval Development and Determination of Point of No Return of Barbatula nuda

作　　者：吴晨 骆小年 段友健 李姣 邢雨忻 季辰跃 李权森 WU Chen;LUO Xiaonian;DUAN Youjian;LI Jiao;XING Yuxin;JI Chenyue;LI Quansen(Key Laboratory of Applied Biology and Aquaculture of Northern Fish in Liaoning Province,College of Fisheries and Life Science,Dalian Ocean University,Dalian 116023,China)

机构地区：[1]大连海洋大学水产与生命学院,辽宁省北方鱼类应用生物学与增养殖重点实验室,辽宁大连116023

出　　处：《水产科学》2025年第2期212-222,共11页Fisheries Science

基　　金：中央引导地方科技发展资金资助项目(2023JH6/100100027);辽宁省教育厅首批“揭榜挂帅”中榜项目(20210095).

摘　　要：为探究北方须鳅仔稚鱼发育特点和最佳投喂时间,采用显微观察法系统观察了北方须鳅仔稚鱼形态发育,开展饥饿试验以研究饥饿对北方须鳅仔鱼形态发育、生长、消化道发育的影响,确定不可逆点。试验结果显示:水温16.2~20.0℃,根据卵黄囊、鳔和体色变化特征,将北方须鳅仔稚鱼发育分为卵黄囊期仔鱼(0~4日龄)、后期仔鱼(5~26日龄)和稚鱼期(27~44日龄);初孵仔鱼全长(4.09±0.11)mm,卵黄囊体积(0.1176±0.0304)mm^(3),3日龄仔鱼可开口摄食,5日龄卵黄囊消失,混合营养期3d。27日龄鼓鳔明显,脊索末端开始弯曲,进入稚鱼期,44日龄与成鱼形态相似;饥饿仔鱼初次摄食率35%,最高摄食率90%(持续2d),饥饿仔鱼活力下降,集群性减弱,贴边独游,肠道萎缩,未形成肠道褶皱,胃蛋白酶活性为(0.54±0.07)U/mL,胰蛋白酶活性为(58.83±13.99)U/mL,均极显著低于对照组(P<0.01);饥饿仔鱼6日龄全长出现负增长,7日龄开始大量死亡,10日龄全部死亡,饥饿不可逆点为7~8日龄,最佳投饵时间为3~4日龄。试验结果初步揭示了北方须鳅早期发育的基本特征,为其早期发育生物学研究及鱼苗投喂策略提供数据参考。In order to explore the developmental characteristics and optimal feeding time of larval Barbatula nuda,the microscopic morphological observation of B.nuda larvae and juvenile was carried out systematically from 0 to 44 days post hatching(dph)and effects of fasting on larval development,growth and digestive tract and the point of no return(PNR)were investigated.The results showed that the early development stage of B.nuda was divided into yolk sac larvae stage(0—4 dph),late larvae stage(5—26 dph)and juvenile stage(27—44 dph)at water temperature of 16.2—20.0℃according to the exhaustion of yolk sac,formation of air bladder and body color.The newly hatched larvae had total length of(4.09±0.11)mm,and the yolk sac volume of(0.1176±0.0304)mm^(3).The initial feeding was observed in the larvae at 3 dph,and the yolk sac was completely exhausted at 5 dph,with mixed trophic of 3 days.At 27 dph,the air bladder drum can be observed clearly,and the end of notochord began to bend,signing the juvenile stage.The B.nuda had similar morphology of juvenile to that of adult at 44 dph.The result of starvation test showed that the initial feeding rate of the starvation larvae was 35%,with the maximum food ingestion rate of 90%for 2 days.Compared with feeding groups,the starvation larvae showed decrease in vitality,weakened clustering,and solitary swimming,without intestinal folds formed.The activities of pepsin and trysin were(0.54±0.07)U/mL and(58.83±13.99)U/mL in the starvation groups,respectively,significantly lower than those in the feeding groups(P<0.01).The degrowth was observed in the starved larvae at 6 dph,with a large number larvae starting to be death at 7 dph and all dead at 10 dph.It was found that the point of no return was 7—8 dph.Therefore,the optimal initial feeding may be 3—4 dph for B.nuda larvae.The findings preliminarily revealed the basic rules of early development of B.nuda and provided basic biological data for the early development biology research and feeding strategies of B.nuda.

关 键 词：北方须鳅 仔稚鱼发育 饥饿胁迫 初次摄食率 饥饿不可逆点 

分 类 号：S965.199[农业科学—水产养殖]