颤藻对凡纳滨对虾生长和免疫相关酶活力的影响

Effects of Oscillatoria sp.on growth and immune activities of litopenaeus vannamei

颤藻(Oscillatoria sp.)是对虾养殖水体中的一种常见蓝藻。通过在凡纳滨对虾养殖水体中投加不同浓度的颤藻,测定凡纳滨对虾的成活率与体长、体重,以及不同颤藻浓度下凡纳滨对虾的免疫相关酶活力,研究颤藻对凡纳滨对虾生长和免疫酶活力的影响。结果表明:颤藻对对虾的成活率、体长和体重有显著影响(P<0.05),随藻浓度增加对虾的成活率、体长和体重呈下降的趋势。颤藻对对虾超氧化物歧化酶(SOD)、过氧化物酶(POD)、酚氧化酶(PO)、碱性磷酸酶(ALP)、谷胱甘肽S-转移酶(GST)、抗菌活力影响显著(P<0.05),低浓度的颤藻诱导酶活力增大,当浓度大于12.5 mg/L时,其酶活力呈下降的趋势。当颤藻浓度为2.5 m g/L和12.5 mg/L时,GST、ALP活力分别达到最大值(39.05 U/mg、73.62 U/g)。以上研究结果说明,颤藻具有一定的毒性,低浓度的颤藻可诱导酶活性增加,高浓度的颤藻能抑制酶的活性和对虾生长。为了保证凡纳滨对虾的健康养殖,养殖水体中的颤藻浓度应该控制在12.5 mg/L以下。

Oscillatoria sp.is a kind of blue-green microalgae flourished in prawn ponds.Different concentrations of Oscillatoria sp.were added into the culture water of Litopenaeus vannamei,the survival rate,length,weight,activity of immune enzyme of prawn were measured,and the effects of Oscillatoria sp.on growth and enzyme activity of prawn were discussed.The results showed that with the increasing of concentration of the alga,the survival rate,body length and weight of prawn declined.SOD,POD,PO,ALP,GST and anti-bacterial activity of prawn were significantly affected（P0.05）.The activity of immune activities of prawn could be increased by low concentration of Oscillatoria sp..When the concentration of Oscillatoria sp.in water exceeded 12.5 mg/L,the activity of enzyme trended toward decreasing.When the concentration of Oscillatoria sp.was 2.5 mg/L,GST reached maximum（39.05 U/mL）;When the concentration of Oscillatoria sp.was 12.5 mg/L,ALP reached maximum（73.62 U/g）.The research results above indicate that Oscillatoria sp.is toxic.Low concentration of Oscillatoria sp.could increase activity of enzyme;while high levels of Oscillatoria sp.could inhibit activity of enzyme and the growth of prawn.Accordingly,the concentration of Oscillatoria sp.in the prawn ponds should be controled below 12.5 mg/L.