Annual changes of total heterotrophic bacteria and Vibrios in the intestine of Apostichopus japonicus and its culture pond
刺参肠道与养殖池塘环境中异养细菌和弧菌数量周年变化

Annual changes of total heterotrophic bacteria and Vibrios in intestine of Apostichopus japonicus and its culture environment were studied from September 2008 to Novemver 2009. We found that the number of bacteria estimated by HPC (Heterotrophic Plate Count) and VBC (Vibrio bacterial Count) had significant seasonal changes in the intestine of A. japonicus and the cultured environment. HPC and VBC in the intestine of A. japonicus ranged from 1.85×105 to 2.17×109 CFU/g and from 4.1×104 to 2.2×108 CFU/g, respectively. HPC and VBC in cultured pond water ranged from 90 to 4.67×105 CFU/mL and from 0 to 5.3×103 CFU/mL, respectively. HPC and VBC in the pond sediment ranged from 9.80×104 to 6.72×106 CFU /g and from 1.01×104 to 5.75×105 CFU/g, respectively. HPC and VBC in cultch sediment ranged from 2.78×105 to 2.57×107 CFU /g and from 4.6×104 to 1.31×107 CFU/g, respectively. The total bacterial count in summer or autumn was higher than other seasons. The ratios of VBC to HPC were also calculated and indicated that the proportion of Vibros reached 43.8% and 43.2% in winter and spring. Although HPC in winter and spring were lower than thoese of summer and autum, the proportions of Vibro were higher in winter and spring than that of summer and autumn, potentially being the reason of high disease incidence during winter and spring. Our results could be useful to healthy culture of sea cucumber.