人工育苗条件下泥鳅仔鱼的摄食与生长

以人工孵化的泥鳅(Misgurnus anguillicaudatus)仔鱼为材料,对其早期阶段的摄食及生长情况进行了研究。结果表明:在水温22~25℃条件下,泥鳅仔鱼3日龄开始摄食,6日龄时卵黄完全耗尽,8~10日龄饥饿仔鱼进入不可逆转点(PNR)期;混合营养期3~4 d。饥饿仔鱼的初次摄食率开始较低,此后上升,到卵黄囊快要耗尽时达高峰(88%),以后又下降。内源性营养期,仔鱼日平均生长率为0.84 mm/d;PNR前的摄食期,饥饿仔鱼的日平均生长率为0.06 mm/d,而摄食仔鱼的日平均生长率为0.45 mm/d;PNR后至死亡前,饥饿仔鱼体长呈负增长,而摄食仔鱼的日平均生长率达0.65 mm/d。摄食仔鱼在孵化后12 d内的全长和日龄呈线性相关:L=0.452 3D 3.129 2,R2=0.953 5;口宽与全长呈正比关系:M=0.154 4L-0.452 5,R2=0.957 6。

Feeding and Growth of Misgurnus anguillicaudatus during Early Development under Artificial Rearing Conditions

Feeding ability and growth of larval Misgurnus anguillicaudatus were investigated under artificial conditions.The results showed that larvae began to feed at 3 DAH(days after hatching).The yolk was depleted completely at 6 DAH.At 8~10 DAH,the unfed larvae,most of which could not feed from the outside,entered the period of PNR.The initial feeding rate was low,and slowly reached the peak when the yolk was exhausted,and then declined reposefully.The highest initial feeding rate was 88%.The growth rate of larvae was 0.84 mm/d during endogenous feeding stage.When they entered feeding period,the unfed larvae almost stopped growing.At the same time,the growth rate of fed larvae decreased to 0.45 mm/d.From PNR to death,unfed larvae displayed negative growth while the growth rate of fed larvae was 0.65 mm/d.The relationship between total length(L) and days of age of the normal larvae within 12 days were presented with L=0.452 3D 3.129 2,R2=0.953 5(n=200).The relationship between mouth width(M) and total length(L) of the loach larvae within 12 days were presented with M = 0.154 4L-0.452 5,R2=0.957 6(n=200).