作　　者： ; ; ; ;

机构地区： 中国科学院南海海洋研究所

出　　处： 《高技术通讯》 2003年第5期87-91,86,共6页

摘　　要： 利用人工繁殖受精卵孵化出的点带石斑鱼仔鱼,在盐度3％、pH7.9、水温26℃的情况下,对其营养转换期的摄食与生长情况进行了观察研究。结果表明:(1)点带石斑鱼卵为少黄卵。仔鱼刚孵出时水面漂浮、偶尔旋转,逐渐转向水中上层倒挂悬浮,至卵黄囊消失时,能水面平游、集群、趋弱光、避强光。仔鱼这种运动生活习性的转变是卵黄囊和油球营养向混合型营养和外源性型营养过渡的生理变化相适应的。(2)仔鱼孵出后第1d,卵黄囊容积由0.0339mm3缩小到0.0054mm3,消耗量达84.07％。油球直径也由0.21mm减缩到0.11mm,缩小程度为47.6％。这与第1d器官发育旺盛有关。(3)卵黄囊和油球营养持续72h,混合营养期仅24h。仔鱼转入外源性营养后,随着口径的增大,饵料由牡蛎受精卵和担轮幼虫、超微轮虫,逐渐向褶皱臂尾轮虫过渡,而且可摄食微囊饲料,摄食比率和摄食强度逐渐增加。充分摄取富含DHA、EPA的适口饵料是后期仔鱼生存的物质基础。(4)饥饿仔鱼初次摄食发生在孵出后72h,摄食率仅为18.1％,而且是“滤食”,96h后逐渐转为主动摄食,120h记录到最高的初次摄食率为70％,此后逐步下降。仔鱼如果在孵出后第8d仍不能建立外源性营养关系,即进入PNR期,第10～11d初次摄食率下降为0,第13天全部死亡。(5)仔鱼在初孵时的平均生长速率为0.25mm/d。 The feeding and growth of the larvae from artificial reproduction of E. malabaricus in the process of nourishing transformation were studied , on conditions of salinity 3 % , pH7.9 and water temperature 26℃ . The results were reported as follows: 1) E. malabaricus eggs is the type of little yolk. Newly hatched larvae floated on water surface and incidentally circumrotated, gradually turned to hang its head adown, and then could swim on surface, gather in weak light and obviate great light when the yolk sac disappeared. The transformation of movement and life style of larvae was seasoned with its physiologic accommodation with feeding transition, from nourishment of yolk sac and oil ball to mixed and exogenous nourishment. 2) During 1 day after posthatching, the larva yolk sac volume was shrunk from 0.0039mm3 to 0.0054 mm3, the its yolk sac consuming rate Was high to 84.07% . The diameter of oil ball was shrunk from 0.21mm to 0. llmm, the shrunk degree high to 47.6% . These were correlation with flourishing organ development during this day. 3) The nourishment from yolk sac and oil ball lasted 72h, mixed nourishment only 24h. The exogenous food was composed of fertilized eggs of oyster, short and small type rotifer, Brachionus plicatilis, and micro-bursa type food. All exogenous food must intensify DHA and EPA, the both were living substance form of post stage larvae. 4) The starved larvae started to feed (sieving food) on the 72nd hour after hatching and erect initial feeding rate only 18.1% , to feed initiatively after the 96th hour. The highest mean feeding rate recorded was 70% after the 120th hour, and gradually fall. The PNR time was on the eighth after hatching,if the larvae couldn' t fetch exogenous food. The initial feeding rate was 0 on 10-llth day after hatching, and the total survival time for unfed larva was 13 days. 5) The mean growth rate was 0.25mm/d for larvae living on yolk sac and oil ball, and a little minus growth when the larvae reached the external feeding stage but no food was available.

关 键 词： 点带石斑鱼 仔鱼 营养转换期 摄食 生长 人工繁殖 受精卵 孵化

领　　域： [农业科学] [农业科学]