珠江肇庆江段赤眼鳟开口后仔、稚鱼的异速生长分析

Allometric growth of Spualiobarbus curriculus larvae and juveniles in Zhaoqing reach of Pearl River

运用实验生态学的方法,对珠江肇庆江段的赤眼鳟(Spualiobarbus curriculus)开口后仔稚鱼的异速生长及其生态学意义进行研究。结果表明,赤眼鳟开口后仔鱼的游泳、感觉和摄食器官快速分化,许多器官的发育存在异速生长:身体各部分中,头长、尾长和头高为正异速生长,腹长在开口后至20日龄为负异速生长,20日龄后为正异速生长;体高也存在正异速生长,但生长拐点(18日龄)前后均为正异速生长。在头部器官中均存在异速生长拐点,吻长、眼径和眼后头长的生长拐点分别是开口后23、19和16日龄。运动器官中,背鳍、腹鳍、臀鳍及尾鳍均存在异速生长,且分别在开口后18、19、17和14日龄达到生长拐点。游泳、感觉及摄食相关的器官的优先发育,使开口后的仔鱼在最短的时间内获得了与早期生存密切相关的各种能力,对适应复杂多变的外界环境具有重要的生态学意义。

Ecological experiment was conducted to study the allometric growth of Spualiobarbus curriculus larvae and juveniles from Zhaoqing reach of Pearl River. The results showed that after the first feeding, the organs associated to swimming, feeling and feeding of larvae differentiated rapidly, and exhibited allometric patterns. Head length, tail length and head height exhibited positive allometric growth, trunk exhibited negative allometric growth before the growth inflexion point at the age of 20 days after opening mouth, while after the growth inflexion point, trunk exhibited positive allometric growth. Body height exhibited positive allometric growth both before and after the growth inflexion point at 18 days after opening mouth. For dimensions of organs in head, the growth inflexion points of rostrum length, eye diameter and post-eye head length were at the age of 23, 19 and 16 days. For swimming organs, dorsal fin, pelvic fin and anal fin exhibited positive allometric growth both before and after the growth inflexion point at 18, 19 and 17 days after opening mouth; but tail fin exhibited positive allometric growth before the ~rowth inflexion point at the age of 14 days feeding, after the growth inflexion point, tail fin exhibited negative allometric growth. The fast development of swimming, feeling, feeding and other organs in exogenous nutrition larvae of S. curriculus, let larval survival ability at the early stage increase in the shortest time, and had important ecological significance to adapt the complex external environment.