鲈鲤仔鱼的异速生长模式

采用实验生态学方法研究了鲈鲤(Percocypris pingi pingi)仔鱼(0～57日龄)的异速生长模式.结果显示:鲈鲤仔鱼全长由慢速生长到快速生长的转折点为25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,均在22 ～ 27日龄出现生长拐点；眼径在14 ～ 15日龄较早出现生长拐点,促使眼睛充分发育,以提高早期仔鱼开口期摄食外源食物的能力；吻长在33～34日龄出现生长拐点,促进了口的充分发育,以适应不同的饵料环境；胸鳍、背鳍、尾鳍、臀鳍和腹鳍分别在13～14日龄、31～32日龄、32 ～33日龄、38 ～39日龄、43 ～ 44日龄出现生长拐点,除胸鳍和尾鳍外,其余各鳍的鳍条均在拐点处分化完全,即鲈鲤仔鱼的游泳能力已得到大幅提高.研究表明,鲈鲤仔鱼的异速生长模式,保证了各重要功能器官的充分发育,以适应多变的环境,有效地保障了其早期的生存,可为育苗生产和野生早期资源的保护提供技术支撑.

Allometric Growth Pattern of Percocypris pingi pingi Larvae

Allometric growth pattern of Percocypris pingi pingi larvae were studied in the laboratory from the day hatched to 57 days. The total length growth rate of larvae changed from slow to fast at the inflexion point of 25 days after hatching (d). Most organisms of larvae exhibited an allometric growth pattern. The growth of head and tail was faster than trunk, and the inflexion point of growth coefficient was at 22-27 d. The inflexion point of growth coefficient of eye diameter occurred at 14-15 d that was earlier than any other organism growth. The inflexion point of growth coefficient of snout length, appeared at 33-34 d; the inflexion point was at 13-14 d, 31-32 d, 32-33 d, 38-39 d and 43-44 d for pectoral fin, dorsal fin, tail fin, anal fin and ventral fin, respectively. Except for pectoral fin and tail fin, the other fins were highly developed at the inflexion point. In the days after hatching at inflexion point of fins, the swimming of larvae was highly improved. The allometric growth pattern of larvae ensured a quickly development of those organisms which have important function to adapt to the complex environment and increase their survival rate. These results may be useful in cultivating fish fry practice and preserving wild resources.