鱼虾混养生态系中细菌动态变化的研究

Variation of bacteria numbers in fish-shrimp mix-culturing ecosystem.

中国对虾和黑鲷混养生态系中几种主要细菌的动态变化研究结果表明 ,养殖初期 ,鱼虾混养池水体中异养菌总量和硝酸盐还原菌数量较低 ,但高于对照的对虾单养池 .随着养殖时间的推移 ,对照池的两种菌的菌量急剧增加 ,8、9月份菌量仍维持在较高水平 ;而混养池的菌量在高温季节虽有增加 ,但仍保持在 10 4 cells·ml-1范围内 ,增长幅度远远低于对照池 ,且 9月底开始下降 .底泥中的细菌数量与水体中细菌有相似的变化规律 ,但一般高于同期水中菌量 1～ 2个数量级 .混养池中的弧菌数量一直低于同期对照池 .可见 ,鱼虾混养可通过对养殖生态系中细菌的激活和调节作用 ,调节生态系统的物质循环 ,使其保持高速、稳定运行 ,为对虾生长提供一个健康而稳定的环境 。

The study on variation of bacteria numbers in Penaeus chinensis-fish mix-culturing ecosystem in 1997. Indicated that at the beginning of culturing season,total number of heterotrophic bacteria and that of nitrate-reducing bacteria in mix-culturing ponds was low,but it was higher than that in mono-culturing shrimp pond. With time going on,the number of bacteria in mono-culturing pond increased rapidly and remained at a high level in August and September,an that in mix-culturing ponds also increased. But the latter increased slowly,and it was never over 10 4 cells·ml -1 and dropped in September. Number of bacteria in bottom of the ponds varied with the similar regulation,but the numbers was 10～100 times higher. The numbers of vibrio in mix-culturing ponds was always lower than that in contrastive pond at the same time. So,in fish-shrimp mix-culturing ponds,the contents of organic matter were lower and the total amount and variability of phytoplankton were higher than corresponding items in mono-culturing pond.It was concluded that mix-culture could stimulate and control the growth of heterotrophic bacteria,accelerate the degradation of organic pollutants,consequently fasten and stabilize the circulation of mater in ecosystem of ponds in culturing season.