拉萨裂腹鱼仔、稚鱼的异速生长模式

Allometric growth pattern of Schizothorax waltoni Regan at larvae and juvenile stages

采用实验生态学的方法对拉萨裂腹鱼(Schizothorax waltoni Regan)0~90日龄的异速生长模式进行研究。结果显示:拉萨裂腹鱼仔、稚鱼全长由慢速生长到快速生长的转折点为28日龄;其多数外部器官均具有异速生长特点,头部和尾部的生长快于躯干部,头长、肛前长、肛后长分别在24~25日龄、36~37日龄、37~38日龄出现生长拐点,头高和体高分别在40~41日龄、49~50日龄出现生长拐点;眼径在18~19日龄较早出现生长拐点,促使眼睛充分发育,以提高早期仔鱼在开口期摄食外源食物的能力;吻长在42~43日龄出现生长拐点,促进了口的充分发育,以适应不同阶段的饵料环境;胸鳍、背鳍、臀鳍、腹鳍和尾鳍分别在18~19日龄、39~40日龄、43~44日龄、46~47日龄、37~38日龄出现生长拐点,其中臀鳍和腹鳍长在拐点前后相对全长均呈现正异速生长,但是拐点后生长指数明显降低,各鳍在仔鱼早期的快速生长使拉萨裂腹鱼仔鱼的游泳能力得到大幅提高。拉萨裂腹鱼仔、稚鱼的异速生长模式,保证了各重要功能器官的充分发育,有效地保障了其开始摄取外源性营养后的生存能力,同时对早期野生资源保护和苗种生产有重要的指导意义。

The allometric growth pattern of Schizothorax waltoni Regan at the age of 0-90 days was studied by experimental ecology.The results showed that the inflection point of larvae growth from slow to fast was 28 days old.Most of the external organs of larvae of S.waltoni Regan had the characteristics of allometric growth.Head and tail grew faster than trunk.Head length,anterior anus length and posterior anus length showed inflection points at 24-25 days,36-37 days and 37-38 days respectively.Head height and body height presented growth inflection points at 40-41 days and 49-50 days respectively;eye diameter presented growth inflection points at earlier 18-19 days,which promoted the full development of eyes,so as to improve the ability of early larvae to eat exogenous food at the opening stage.Snout length presented growth inflection points at 42-43 days,which promoted the full development of mouth to adapt to different conditions.The growth inflection points of pectoral fin,dorsal fin,pelvic fin,caudal fin appeared at 18-19 days,39-40 days,43-44 days,46-47 days and 37-38 days respectively.The relative total length of pectoral fin and pelvic fin showed positive allometric growth before and after inflection point,but the growth index after inflection point decreased significantly.The swimming ability of larvae of S.waltoni Regan greatly improved.The allometric growth pattern of larvae of S.waltoni Regan guarantees the full development of important functional organs,effectively guarantees the survival ability of larvae after the beginning of exogenous nutrition,and has important guiding significance for early wild resource protection and seedling production.