红螯螯虾的室内人工育苗

Indoor artificial breeding and juvenile nursing of Cherax quadricarinatus

于1996-1998年,在浙北地区,对从澳大利亚引进的红螯螯虾进行亲虾培育、人工越冬,怀卵孵化,室内人工育苗技术的研究。研究表明,在浙北地区,2.8～4.9g的幼虾经5个月左右的饲养可以达到性成熟并部分怀卵,利用电厂余热水水泥池人工越冬的成活率可达70%以上。越冬后亲虾在水温20℃以上即开始交配怀卵,怀卵盛期4-6月。红螯螯虾一年可产卵4次,但只有第一、二次怀卵可用于育苗生产,个体一次怀卵量较少,一般为400～500粒,但群体怀卵比率较高。试验还表明,红螯螯虾出膜幼体即呈幼虾状,需依附母体7～10d后才营独立生活并开口摄食外源性饵料,所研制的幼虾Ⅰ号饲料为红螯螯虾室内人工育苗较好的开口饲料。室内人工育苗成活率可达60%以上。

Studies on culture of parent crayfish, winter rearing, hatching and indoor artificial breeding of the red crayfish (Cherax quadricarinatus) were carried out from 1996 to 1998 in the northern region of Zhejiang Province. Results showed that the red crayfish is appropriate for farming and breeding in Zhejiang Province. In the northern region of Zhejiang Province, the juvenile crayfish (sizes of 2.8-4.9g) can grow to sexual maturity and the survival rate in pond was over 70% during the winter seasons because of warm water supply from a local power plant. In February, when the water temperature went up to 20 ℃, the parent red crayfish began to copulate and breed, but the epacme were observed in April to June. The red crayfish can spawn four times a year, but only the first and the second hatches are useful for juvenile nursing purpose. A female brood normally ovulate 400-500 eggs, but the spawning rate of the population in a pond is commonly high. The red crayfish develops from fertilized egg to juveniles directly, which is quite different from crabs and shrimps. The hatch need stay on the pleopod of the female brood for 7 to 10 days, and then begin to leave and live on extraneous foods. The juveniles do not need live food absolutely. A formulated feed has been developed successfully for nursery stage juvenile.Temperature regulation and intensive management during the indoor nursery stage are very important for juvenile nursing success, and the survival rate can reach up to 60%.