在轮虫培养中用敌百虫杀灭桡足类的试验

针对鱼、虾、蟹人工苗种生产中经常遇到的由于轮虫中混杂桡足类导致育苗失败的实际情况,探讨利用轮虫和桡足类对晶体敌百虫忍耐性的差异,在不影响轮虫生长、繁殖的情况下彻底清除桡足类的方法。结果表明:轮虫和桡足类对敌百虫的忍耐性有较大的差异,轮虫和桡足类的96h敌百虫安全浓度分别为2.0mg/L和0.2mg/L;致死浓度分别为3.0mg/L(96h)和0.4 mg/L(72h);在敌百虫添加浓度0.5~2.0mg/L条件下,敌百虫对轮虫繁殖率的影响随添加浓度加大而增加,但这一影响是可逆的,一般在2~3d后即可恢复正常。在苗种生产实际中,将敌百虫处理浓度定为1.0~1.5mg/L较为适宜。

Experiment on the use of dipterex to eradicate copepod in the rearing of rotifier

Due to the failure of seed rearing by rotifier with copepod in the artifical seed rearing of fish,shrimp and crab,the paper deals with rotifier and copepod to tolerate the differences of crystal dipterex.The method of thoroughly eradicating copepod without affecting the growth and breeding of rotifier was carried out.The results revealed that rotifier and copepods had greater differences to tolerate dipterex.The safety concentration of dipterex for rotifier and copepod in 96 h was 2.0 mg/L and 0.2 mg/L,respectively;the lethal concentration was 3.0mg/L(96 h) and 0.4mg/L(72 h),respectively.Under the conditions of dipterex concentration of(0.5)-2.0mg/L,the increase of the effect of dipterex on rotifier breading rate with the increase of the concentration,but this effect was reversible,and might recover to normal after 2-3 days.In the practice of seed rearing production,it is much suitable to set the concentration of dipterex at 1.0-1.5 mg.