点带石斑鱼亲鱼培育、产卵和孵化的试验研究

STUDY ON PARENT FISH REARING,SPAWNING AND HATCHING OF EPINEPHELUS MALABARICUS(BLOCH & SCHNEIDER)

采用经埋植外源激素法诱导所得的点带石斑鱼功能性雄鱼和人工养殖的雌鱼进行亲鱼培育、产卵和孵化的试验研究。在 1 999— 2 0 0 0年的两年中 ,繁殖仔鱼 71 0 3万尾。结果表明 ,雌鱼的绝对生殖力为 535.0 1万粒卵 ,相对生殖力为 81 0 .2 1粒 /g体重。水泥池中培育的点带石斑鱼能自然产卵 ,产卵能常在 1 8:30— 2 1 :0 0间进行。产卵水温为 2 1 .0— 31 .5℃。产卵与水温相关 ,水温高于 2 4℃时 ,产卵呈一定的周期性 ,即连续产卵 5— 7天 ,停产数天后再开始下一个产卵周期 ;水温低于 2 4℃时 ,产卵受到抑制。水温对胚胎发育有明显的影响 ,水温 2 5.5— 2 8.5℃胚胎发育时间为 2 1h53min ,仔鱼活力好。盐度为 30— 33时 ,胚胎发育正常 ,盐度降低造成孵化率下降。

This paper deals with the rearing,spawning and hatching of Epinephelus malabaricus(Bloch & Schneider) under controlled water environmental condition. The male fish that was used in the experiment had been implanted 17-methyltestosterone,and had completed sex reversal. The female was selected from the culture-cage. During 1999_2000,71 million of larva fish were hatched in the experiment. The results show that the absolute productivity is 5.35 million of per female,and the relative productivity is 810.21 eggs/g(body weight). The fish cultured in a cement tank spawns in a natural way;the spawning usually occurs from 18:30 to 21:00,and under the water temperature 21.0_31.5℃. Spawning behavior is related to water temperature. When water temperature is above 24℃. spawning appears periodically. After a continuous spawning for 5_7 days,there is a suspense for a few days before the next cycle starts. When water temperature is below than 24℃,the spawning is restrained. Temperature has an significant effect on the embryonal development of E. malabaricus,the duration of the embryonal development is 21h53min with 25.5_28.5℃,and the quality of the fish larvae is high under this condition. Salinity affects the embryonal development of E.malabaricus. The embryonal development is normal for salinity of 30_33,and the hatching rate is reduced as salinity decreases. Further,this paper described different morphological characteristics of different stages of embryonal development,analyzed optimum temperatures for its hatching,and summarized the techniques of artificial propagation of E. malabaricus for culturing in factories.