盐度对凡纳滨对虾生长与免疫功能的影响

Growth and Immunities of the Shrimp,Litopenaeus vannamei(Boone) Exposed to Different Salinity Levels

分析了盐度对凡纳滨对虾Litopenaeus vannam ei（Boone）生长、耐低氧能力及一些免疫指标的影响.实验结果表明,其它环境因子相对恒定的条件下,凡纳滨对虾能在盐度5～30范围内生存、生长,其中：在盐度15～25环境中生长较快;盐度为25时凡纳滨对虾耐低氧能力最好,盐度下降至5时,耐低氧能力显著下降;5～10的低盐环境使凡纳滨对虾血细胞密度、溶菌活力明显下降,在盐度15～25的环境中凡纳滨对虾抗菌活力、溶菌活力最高,PO活性和SOD活性表达与体液抗菌活力、溶菌活力没有直接相关性.β-葡聚糖可提高凡纳滨对虾对低盐度和盐度变化的适应能力,但对个体生长没有影响.

The growth rates and several indexes involved in immune function of the shrimp, Litopenaeus vannamei, exposed to different salinity levels for 50 d were analyzed. The shrimp could live in water with a salinity ranging from5 to 30 and gained some growth normally. The optimal salinities for the animal were 15-25, in which the shrimp got a high growth rate level, a great endurance for low dissolved oxygen and a great antibacterial action and bacteriolysis, while the phenoloxidase activity and superoxide dismutase activity of the shrimp appeared lower level. Low salinities 5 - 10 could create an immunosuppressive state by significantly decreasing the bacteriolysis and reducing total haemocyte count of the shrimp. However, taking in β-glucan preparation by diet would enhance resistance to low salinity level and salinity transformation, while it didn＇t seem to contribute to the growth of the animal.