凡纳滨对虾高位池养殖水体细菌变动及其与理化因子的关系

Bacteria variation in Litopenaeus vannamei high level ponds and its relation with physical-chemical factors

自2008年4月至8月,在广东省汕尾市红海湾凡纳滨对虾(Litopenaeus vannamei)高位池养殖基地全程采集养殖池塘水样,检测水体细菌类群和理化因子,分析养殖过程中细菌类群的数量变化规律及其与环境因子的关系。结果显示,养殖过程中水体异养细菌、弧菌(Vibrio)和芽孢杆菌(Bacillus)的数量波动性较大,其中异养细菌波动范围1.35×104～1.39×106cfu.mL-1,平均4.73×105cfu.mL-1;弧菌波动范围1.05×103～5.20×104cfu.mL-1,平均1.80×104cfu.mL-1;芽孢杆菌波动范围0.11×103～4.30×103cfu.mL-1,平均6.6×102cfu.mL-1;粪大肠菌群(fecalcoliform)大多在1.0×102cfu.L-1以内,平均0.97×102cfu.L-1,远低于无公害食品海水养殖用水水质标准。对细菌与理化因子的单因子分析显示,异养细菌与溶解氧(DO)呈显著的负相关性(P<0.05),弧菌与pH呈极显著的负相关性(P<0.01),与化学需氧量(COD)和总磷(TP)呈显著的正相关性(P<0.05)。多因子偏相关分析显示,异养细菌和弧菌与DO、pH、COD、TP的相关关系均不显著(P>0.05)。结果表明,调查的养殖池塘对虾生长良好,该养殖池塘是安全、基本健康的系统,水环境中细菌数量受养殖系统中生物、环境因子及人为因素的影响和制约。

From April to August,2008,we had collected water sample in high level ponds of Litopenaeus vannamei at Honghai Bay,Shanwei,Guangdong to study its significant bacterial population and physical-chemical factors,and to analyze the variation of bacterial population and its relation with environmental factors during the culture period.The results show that the amounts of heterotrophic bacteria,Vibrio and Bacillus in water change rather greatly.Specifically,the heterotrophic bacteria range from 1.35×10^4 cfu·mL^-1 to 1.39×10^6 cfu·mL^-1,4.73×10^5 cfu·mL^-1 on average;as for Vibrio,the range is 1.05×10^3～5.20×10^4 cfu·mL^-1,1.80×10^4 cfu·mL^-1 on average;and for Bacillus,the range is 0.11×10^3～4.30×10^3 cfu·mL^-1,6.6×10^2 cfu·mL^-1 on average;the amount of fecal coliform is generally less than 1.0×10^2 cfu·L^-1 with an average of 0.97×10^2 cfu·L^-1,which is much below the standard for pollution-free food and aquaculture water quality.Additionally,the correlation analysis between bacteria amount and physical-chemical factors reveals that the heterotrophic bacteria amount and DO show a significant negative correlation （P〈0.05）,while Vibrio amount shows a very significant negative correlation with pH （P〈0.01）but a significant positive correlation with COD and TP （P〈0.05）.The multi-factor partial correlation analysis reveals that the correlation between heterotrophic bacteria and Vibrio,DO,pH,COD,TP is not significant （P〉0.05）.To sum up,L.vannamei grows well in the investigated ponds,which is proved a safe and relatively healthy system,and the bacteria amount in water environment is affected and restricted by biological,environmental and artificial factors.