【作者】 盖力强；

【导师】 安瑞永；

【作者基本信息】 河北师范大学 ， 生态学， 2008， 硕士

【摘要】 江鳕(Lota lota)是鳕科鱼类中唯一一种淡水鱼类,因其肉质鲜美,营养丰富,肝脏较大,而具有很高的食用和经济价值。江鳕在我国只分布于新疆的额尔齐斯河和黑龙江、鸭绿江水系。由于过渡捕捞,近年来数量日趋减少,已被列为国家二级保护鱼类,所以江鳕的保护和养殖开发迫在眉睫,但目前关于江鳕的人工养殖还未见有成功的报道。为此,本文进行了江鳕苗种培育技术的初步研究,观察了江鳕胚后早期发育期的生物学特点;探讨了不同的开口饵料、转饵饵料、幼鱼驯化饵料及其它环境因子对江鳕仔幼鱼生长发育的影响;并专门研究了不同水温对江鳕幼鱼摄食生长的影响。主要研究结果如下:1.江鳕的初孵仔鱼通常比其它鱼类的仔鱼身体微小(约3㎜),卵黄囊相对较大;仔鱼的肝脏、消化管等器官发育缓慢,上浮期特别是平游阶段持续时间较长,摄食开口期很晚,孵化出膜后12 d -15 d才开口。这与江鳕对低温水环境长期适应选择的结果有关。2.根据江鳕鱼苗发育时期的形态、结构和运动、食性等变化特点,把江鳕苗期的发育初步划分为:仔鱼上浮期、仔鱼平游期、仔鱼开口期、仔鱼转饵期(稚鱼期)和幼鱼期。3.江鳕仔鱼对低温条件变化的适应范围较宽,0℃-12℃水温都可正常生存,能耐低溶氧,在3 mg/L的水溶氧下照样正常生存。仔鱼有趋弱光性,到幼鱼逐渐变为避光行为;生活习性随发育时期的不同出现由上浮—平游—底栖的转变;发育后期对隐蔽场所的需求明显。4.江鳕仔鱼以视觉摄食为主;对开口饵料选择有专一性,最好的开口饵料是淡水浮游的活轮虫,用轮虫开口的成活率高达95.42%。江鳕存在复杂的转饵过程,摄食的食物种类和大小随江鳕生长发育及生活方式的变化而变化。转饵饵料以桡足类和枝角类最好,成活率达可达70.80%。5.幼鱼适口的饵料选择,是江鳕产业化养殖的前提。通过对幼鱼的饵料驯化证明,江鳕幼鱼可以鲤科鱼类的水花、乌仔为食,也可以摄食新鲜杂鱼的碎肉块。短期的全价配合饲料的驯化投喂,有40%左右的幼鱼能够摄食,证明江鳕具有摄食人工全价配合饲料的潜力。6.通过六个不同温度水平(12℃、15℃、18℃、21℃、24℃、27℃)的养殖试验显示,在15℃左右的水温下,江鳕幼鱼的摄食率、特定增长率都表现出最大,饵料系数则最低。方差分析表明,不同水温对江鳕幼鱼的摄食率(FR)、饵料系数(FC)、特定生长率(SGR)均有极显著差异(F4, 10=20.448, p=0.00008;F4, 10=21.815,p=0.00006;F4, 10=33.688,p=0.00001),摄食生长效果15℃水平﹥18℃水平﹥12℃水平﹥21℃水平﹥24℃水平。在27℃左右时,江鳕一般不再摄食,直至饿死。7.利用模型y=aT2+bT+c拟合分析水温(T)与日摄食量(I0)、饵料系数(FC)、摄食率(FR)、特定生长率(SGR)、相对增重率(RW)、相对全长增长率(RL)之间的关系,得出: I0=(-0.00267)T2+(0.08144)T+(-0.01379) (P<0.01,r=0.9635) FR=(-0.01853)T2+(0.577757)T+(2.47605) (P<0.01,r=0.9304) FC=(0.069365)T2+(-2.1071)T+(20.5636) ( P<0.01,r=0.9452) SGR=(-0.01194)T2+(0.361139)T+(-1.2584) (P<0.01,r=0.9396) RW =(-0.59948)T2+(18.1171)T+(-69.82) (P<0.01,r=0.9251) RL=(-0.13429)T2+(3.97881)T+(-15.993) (P<0.01,r=0.9726)根据上述SGR与水温(T)之间的相关性方程,证明江鳕幼鱼最适生长温度为15.12℃,这与摄食生长试验结果基本吻合。更多还原

【Abstract】 Burbot,Lota lota is the only species of freshwater fish among the family Gadidae. Because of its delicious meat, abundant nutrition and bigger liver,it has high edible and economic value.In China,the distribution of this species is only limited in Erqisi River of Xinjiang Province,Heilongjiang and Yalujiang water systems.In recent years,the number of burbot decreases gradually with excess catching,therefore,it has been listed as rankⅡnational protected fish.It is urgently to protect burbot and exploit its breeding.Up to now, artificial breeding technology of burbot has not been reported,in the present study,the techniques of burbot larvae culture,especially the effect of temperature on the food intake of its juvenile period were explored.The main results are as follows:The early larvae (about 3㎜) are smaller than that of the other kinds of fish larvae. It has relative bigger yolk bag.Its floating period,especially flat swimming,lasted longer time,its livers and other organs developed slowly and the beginning time of eating is more later (12-15d).That may be related to the result of adapting to low water temperature for long time. The larval development of burbot was divided into five periods based on the morphology, structures,movement and types of food consumption at different developmental period.They are seeding floating,flat swimming,mouth opening,bait changing (seeding period)and juvenile fish.Early young fish adapted to a wide range of temperature change, which can survive from 0℃to 12℃and have low dissolving oxygen,even on the conditions of 3 mg/L.The early larval burbot is positive to faint light, but the juvenile fish becomes negative to light.Living habit changed from floating to flat swimming and then bottom dwelling with different growing period.Shelter is more necessary at late developmental period.Food intake is stimulated by vision in the baby period of burbot,the baby fish has special choice to the bait when began to eat;the best bait for larval burbot beginning to eat was rotifer in fresh water and the surviving rate reached 95.42%.Burbot has complex procedure of baiting transition,the type and size of baits changed with the changing of growth and living style.The bait selecting of juvenile is the precondition of burbot breeding industrialization. Bait domesticating for juvenile showed that burbot can feed on spray of carp fish,larvae of carp fish and also the fresh fish pieces.After shortdated domestication of artificial feed,about 40% juvenile can get food,which showed burbot has potential to eat artificial feed.The result of breeding at six temperature level(12℃、15℃、18℃、21℃、24℃、27℃) showed,the eating rate and SGR are highest,bait index is lowest at 15℃of water.The analysis of variance showed that there has significant effects on FR、FC、SGR of burbot in different temperature(F4, 10=20.448,p=0.00008;F4, 10=21.815,p=0.00006;F4, 10=33.688,p=0.00001),the result of growth increasing by food intake is:15℃﹥18℃﹥12℃﹥21℃﹥24℃.When at about 27℃,burbot hadn’t eat any more,even to death.Result of analyzing the relations between temperature and I0、FC、FR、SGR、Rw、RL by the model of y=aT2+bT+c showed: I0=(-0.00267)T2+(0.08144)T+(-0.01379) (P<0.01,r=0.9635) FR=(-0.01853)T2+(0.577757)T+(2.47605) (P<0.01,r=0.9304) FC=(0.069365)T2+(-2.1071)T+(20.5636) ( P<0.01,r=0.9452) SGR=(-0.01194)T2+(0.361139)T+(-1.2584) (P<0.01,r=0.9396) RW =(-0.59948)T2+(18.1171)T+(-69.82) (P<0.01,r=0.9251) RL=(-0.13429)T2+(3.97881)T+(-15.993) (P<0.01,r=0.9726)According to y=aT2+bT+c to analyze the pertinence between SGR and temperature,the result showed the best suitable temperature of baby fish of burbot is 15.12℃.The result is basically consistent with the experimental data of feeding and growth.更多还原