Physical-chemical factors associated with the dynamic change of bacterial quantity of alimentary tract and environment in Babylonia areolate industrial aquaculture

With the aims to master the dynamic change of bacteria quantity of alimentary tract and aquaculture environment in Babyloniaareolate, TCBS and nutrient AGAR cultivation method was applied to detection vibrio and heterotrophic bacteria quantity respectively, fluorescence microscopy was applied to detection water total bacteria (WTB). In addition, the main physical-chemical factors including temperature(T), salinity(S), pH, dissolved oxygen(DO) and major nutritive salt of water and sediment, were investigated. The results show that the quantity of WTB, water Vibrio(WV) and sediment Vibrio (SV) wave form 4.8×10⁴~3.8×10⁵ cells/mL, 2.1×10²~1.2×10⁴ CFU/mL and 6.0×10⁴~1.9×10⁶ CFU/g separately. Heterotrophic bacteria and Vibrio of Alimentary tract(AV) wave from 4.3×10⁴~5.9×10⁶ CFU/g and 2.0×10²~7.5×10⁵ CFU/g separately. Correlation analysis results show that the quantity of heterotrophic bacteria in Alimentary tract(AHB) and AV both are very significant positive correlation with nitrite (P < 0.01), negative correlation with pH (P < 0.05) and salinity (P < 0.05). WTB is negative correlation with dissolved oxygen (P < 0.05), WV is negative correlation with total phosphorus (P < 0.05) and others are not obvious. Principal component analysis(PCA) show that WTB, WV, SV, as well as AHB and AV mainly affected by temperature, ammonia nitrogen and nitrite from September to the middle of November (autumn) while by water dissolved oxygen more in winter. In particularly, salinity and pH should be monitoring during the whole cultivation period.