头孢氨苄对斑节对虾幼体发育及育苗水体细菌数量的影响

The effects of Cefalexin on larval development of Penaeus monodon and changes in the number of heterotrophic bacteria and vibrios in larval rearing ponds

研究了不同浓度头孢氨苄(Cefalexin)对斑节对虾Penaeusmonodon幼体发育以及对斑节对虾育苗水体中异养菌总数和弧菌数量的影响。在试验初期,无论是对照组还是施用头孢氨苄的各试验组,育苗水体中的总异养菌数量和弧菌数量都呈现出较为明显的上升趋势;在第二次施用头孢氨苄后,各试验组的异养菌总数和弧菌数量的增幅明显低于对照组(或出现异养菌总数和弧菌数量缓慢下降),而对照组异养菌总数和弧菌数量则呈现显著的上升。施用0.5～1.0μL·L-1头孢氨苄对育苗水体中的总异养菌有显著的杀灭及抑制作用,但对弧菌数量杀灭及抑制作用并不显著;施用1.5μL·L-1头孢氨苄对育苗水体中的总异养菌和弧菌数量的杀灭及抑制作用显著。当幼体变态发育至仔虾第8天(P8)时,对照组异养菌总数和弧菌数量分别达6.33×105和3.55×104CFU·mL-1,均远远高于试验组的异养菌总数和弧菌数量增长的幅度。试验组的幼体变态到P1期的时间,比对照组缩短了10h以上;试验组的成苗率也比对照组提高了3.2%～13.1%。

The effects of different dosage of Cefalexin on larval development of Penaeus monodon and changes in the number of heterotrophic bacteria and vibrios in larval rearing ponds were studied. During experimental initial stage, whether control or trials, the number of heterotrophic bacteria and vibrios in pond waters increased. After Cefalexin was used again, the number of heterotrophic bacteria and vibrios in all trails＇ pond waters were obviously lower than that of the control, and the number of heterotrophic bacteria and vibrios in control＇s pond waters were obviously raised. The 0. 5 - 1.0 μL·L^-1 dosage of Cefalexin can markedly affect to kill and restrain the growth of heterotrophic bacteria in raising seedling pond waters （ P 〈 0.05） , but can not obviously restrain the growth of vibiros （ P 〉 0.05） . The 1.5 μL·L^-1 dosage of Cefalexin can significantly affect to kill and restrain the growth of heterotrophic bacteria and vibiros in raising seedling pond waters （ P 〈 0.01 ）. When larvae developed to the eighth day of post-larval （ P8 ） , the number of heterotrophic bacteria and vibtio in control＇s pond waters is 6. 33 × 10^5 and 3.55 × 10^4 CFU·mL^-1 , respectiveiy. It was well above the trails＇. The time of larvae developing to P1 is above ten hours ahead of the control＇s. Survival rate of trials is 3.2% - 13.1% higher than the control＇s.