摘要 为研究鸭绿沙塘鳢(Odontobutisyaluensis)仔稚鱼发育特点，并确定仔鱼最佳投饵时间及饥饿不可逆点(point of no return, PNR)，在水温19.7～26.7 ℃下，研究了饥饿胁迫对鸭绿沙塘鳢仔鱼生长、形态和行为的影响。结果表明：鸭绿沙塘鳢仔稚鱼发育较独特，鳍条在胚胎期已完全分离，鳞片初发生时卵黄囊未完全消失；根据鳞片形成的特点，将鸭绿沙塘鳢仔稚鱼发育划分为仔鱼期(孵化后0～14日龄)和稚鱼期(孵化后15～44日龄)；初孵仔鱼全长为(7.72±0.09)mm，卵黄囊体积为(0.74±0.04)mm3，口张开，肛门贯通，尾骨上翘，耳石、鳃弓、鳃丝、齿及各鳍鳍条均可见；孵化后1日龄仔鱼开口，4日龄仔鱼卵黄囊消耗50%，15日龄仔鱼鳞片首先出现在尾柄中轴线附近，发育进入稚鱼期，18日龄稚鱼卵黄囊消耗90%，30日龄稚鱼卵黄囊及油球消失，44日龄稚鱼头顶部和鳃盖处的鳞片覆盖形成，鳞被完全，发育进入幼鱼期；鸭绿沙塘鳢全长与孵化后日龄呈二次多项式函数关系，卵黄囊体积与孵化后日龄呈对数函数关系；鸭绿沙塘鳢孵化后1日龄仔鱼开口率为40%，2～8日龄仔鱼开口率达最高值100%，9日龄仔鱼开口率开始下降，12～13日龄仔鱼到达饥饿不可逆点(PNR)，13～14日龄饥饿仔鱼累计死亡率达50%，18日龄饥饿稚鱼全部死亡；投喂组仔鱼的全长、眼径、尾柄高、卵黄囊体积和鳔体积,分别从6、8、5、1、5日龄起显著高于饥饿组(P<0.05)，饥饿仔鱼的全长、眼径、尾柄高和鳔体积,分别从14、13、13、10日龄起出现负增长，这表明饥饿对仔鱼生长发育有延迟作用。研究表明，鸭绿沙塘鳢在仔鱼期器官发育较完善是对栖息地山区河流生态适应的结果，其最佳开口时间为孵化后1～2日龄，PNR为12～13日龄。
Abstract: In order to study the developmental characteristics of sleeper (Odontobutisyaluensis) larvae and juvenile, and to determine the best feeding time and the point of no return (PNR) of larvae, the effects of starvation stress on the growth, morphology and behavior of the sleeper larvae from wild broodstock sleeper were investigated in a 0.5 m×0.3 m×0.4 m aquarium at water temperature from 19.7 ℃ to 26.7 ℃. The results showed that development of the larvae and juvenile was uniquely characterized by complete separation of the fin rays in the embryonic stage, and without complete exhaustion of the yolk sac at the first appearance of the scales. Based on the characteristics of scale formation, the development of the sleeper was divided into larval stage (0 day to 14 days post hatch) and juvenile stage (15 days to 44 days post hatch). The newly hatched larvae had total length of (7.72±0.09)mm, the yolk sac volume of (0.74±0.04)mm3, with the open mouth and anus, coccyx upturned, otoliths, gill arches, gill filaments, teeth, and fin rays of each fin. 1 dph (day post hatch, dph) larvae began to the initial feeding; at 4 dph, the yolk sac was consumed by 50%; at 15 dph, the scales first appeared near the central axis of the caudal peduncle, and developed into the juvenile stage. At 18 dph, the yolk sac was consumed by 90%; at 30 dph, the yolk sac and oil globules was disappeared; at 44 dph, the top of the head and the operculum was covered with scales. The scales were completely covered, and then the early development turned into the young stage. The relationship between the total length and the day post hatching showed a quadratic polynomial function; the relationship between yolk sac volume and the day post hatching showed a logarithmic function. At 1 dph, the larvae had initial feeding rate of 40%; at 2 dph to 8 dph, reached the peak value of 100%; at 9 dph, it began to decline; at 12 dph to 13 dph reached PNR; the 13 dph to 14 dph, starved larvae had a cumulative mortality rate of 50%; at 18 dph, starved larvae all died. There were significantly higher total length, eye diameter, caudal peduncle height, yolk sac volume, and swim bladder volume in larvae in the feeding group than those in the starvation group at 6, 8, 5, 1, and 5 dph, respectively (P<0.05). The total length, eye diameter, caudal peduncle height and swim bladder volume were shown to be negative growth from 14, 13, 13, and 10 dph, respectively, indicating that starvation has a delayed effect on the growth and development of larvae. The findings indicated that the relatively complete organ development of the sleeper at the larval stage is the result of ecological adaptation to the mountain river in the habitat. The optimal feeding time for the sleeper larvae was 1 dph to 2 dph, with PNR at 12 dph to 13 dph.
李文康, 骆小年, 段友健, 李姣, 吴晨. 鸭绿沙塘鳢仔稚鱼发育观察及饥饿不可逆点的确定[J]. 大连海洋大学学报, 2023, 38(1): 32-42.
LI Wenkang, LUO Xiaonian, DUAN Youjian, LI Jiao, WU Chen. Observation on development of larvae and determination of point of no return in sleeper (Odontobutis yaluensis). Journal of Dalian Ocean University, 2023, 38(1): 32-42.
2023, Vol. 38 
