The dynamic study of bacteria from autumn to winter in the Litopenaeus vannamei Ponds

The densities changes of heterotrophic bacteria,vibrio,bacillus in the water bodies and sediment in four Litopenaeus vannamei low salinity ponds was surveyed in Doumen,Zhuhai from September of 2007 to February of 2008.The aim of the study was to evaluate the variations of the main bacteria groups in ponds from autumn to winter to offer the basic data for healthy culture.Results showed that the bacteria densities of water was not stable in early culture period,but it became more and more stable in the middle and end of the experiment;the bacteria dynamics was stable in sediments.The bacteria densities of sediments was more than about 100~1000 fold in water bodies.The ranges of heterotrophic bacteria,vibrio,bacillus in the waters were 1.8×103~1.2×105/mL,1.4×102~4.0×103/mL,1.6×102~1.7×103/mL,respectively,the mean density of Heterotrophic bacteria was 1.95×104/mL;In the sediment,the ranges were 1.0×106~2.2×107/g,7.0×103~4.7×105/g,4.7×104~2.4×106/g,respectively,the mean of Heterotrophic bacteria was 9.16×106/g.