广东池塘培育条石鲷仔、稚、幼鱼的早期发育和生长

Early development and growth of larval, juvenile and young Oplegnathus fasciatus reared in pond in Guangdong Province

  • 摘要: 研究了在广东饶平池塘人工培育的条石鲷(Oplegnathus fasciatus)仔、稚、幼鱼的形态发育和生长特性。条石鲷初孵的0日龄仔鱼全长(1.875 50.060)mm,卵黄囊长径(0.7390.135)mm,短径(0.4890.089) mm。在水温为22~23 ℃的前期培育条件下,3日龄仔鱼的卵黄被完全吸收,而到第4天,仅见到卵黄囊残余物。混合营养期仅1 d。在水温为24~27 ℃、盐度29~30、pH 7.4~8.2条件下,3日龄的仔鱼已开口,但仍不能主动摄食,4日龄仔鱼便进入了外源性营养阶段。8日龄鳃弓形成,12日龄尾椎弯曲,25~30日龄仔鱼的背鳍、胸鳍、腹鳍、臀鳍、尾鳍先后出现,鳞片出现,进入稚鱼期。40日龄进入幼鱼期,全身覆盖鳞片,条带全部形成,形态与成鱼相似。全长、体长、体质量和体高随日龄的生长速度均呈显著的指数函数关系,体高/全长之比在0~5日龄时急剧下降,随后逐渐增高,20日龄后趋于平缓。

     

    Abstract: We investigated the early development and growth of larval, juvenile and young Oplegnathus fasciatus reared in pond in Raoping, Guangdong Province. The total length of newly-hatched larvae (0 dah) was (1.875 50.060) mm with a yolk sac long in (0.7390.135) mm and short in (0.4890.089) mm. Under early rearing temperature of 22~23 ℃, the yolk was absorbed for 3-dah larvae, and only relic yolk sac could be found in 4-dah larvae, lasting only 1 d for mixotrophic period. Under conditions of 24~27 ℃, salinity 29~30 and pH 7.4~8.2, mouth opened for 3-dah larvae, but unable to forage actively; 4-dah larvae turned to exotrophic period; gill arch formed for 8-dah larvae; caudal vertebrate flexion occurred for 12-dah larvae; for 25~30-dah larvae, whose dorsal fin, pectoral, pelvic fins, anal fin and caudal fin appeared successively, and scales occurred, entered juvenile stage. For those who entered young fish stage in 40 dah, the whole body was covered by scales and bands formed, similar with adults in morphology. Correlation among total length, body length, body weight, body height in relation to daily growth could be expressed by exponent function; the ratio of body height to total length sharply decreased during 0~5 dah, after that it gradually increased and became stable after 20 dah.

     

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