低盐胁迫对刺参非特异性免疫酶活性及抗菌活力的影响

Effects of low salinity stress on the activities of non-specific immune enzymes and antibacterial activity of sea cucumber Apostichopus japonicus

以养殖刺参为研究对象,测定了不同强度盐度胁迫对刺参生存、生长及体腔液中超氧化物歧化酶(SOD)、溶菌酶(LZM)活性及抗菌活力的影响。结果表明,1)盐度16实验组刺参存活率最低,为66.7%,与其他各实验组及对照组差异显著(P<0.05);盐度18、20实验组存活率分别为88.9%、92.6%,无显著差异(P>0.05);盐度≥22时,刺参能够全部存活,实验组刺参生长与对照组相比差异显著(P<0.05)。盐度≤20时,刺参生长表现为负增长。2)刺参体腔液中SOD、LZM活性及抗菌活力随时间变化呈现总体降低的趋势。实验开始时,各实验组SOD、LZM活性及抗菌活力均为最高值,30d时,各实验组SOD、LZM活性及抗菌活力降至最低。低盐胁迫会显著影响刺参正常生存、生长,并导致刺参免疫力降低,增加对病原菌的易感性,从而诱导疾病发生并造成死亡。

Experiments were conducted to evaluate the effects of different salinity on growth,non-specific immunity and antibacterial activities of sea cucumber Apostichopus japonicus.The results showed that：（1）The survival rate of treatment A（salinity 16）was reduced to 66.7%（P〈0.05）,which was significantly different with other treatments and the control（P 0.05）.During the experiment,no mortality of sea cucumber was observed among the treat-ments at salinity of 22and above.The specific growth rate of sea cucumber showed significant difference between treatments and control（P〈0.05）.At salinity of 20and below,sea cucumber showed a negative growth.（2）The activities of superoxide dismutase（SOD）,lysozyme（LZM）and antibacterial activity decreased with time,that is,from the maximum values at the beginning of the experiment to the minimum values at 30d.We conclude that low salinity stress can significantly affect the survival and growth of sea cucumbers by reducing the immunity and increasing the susceptibility to pathogens,resulting in disease and mortality.