摘要
采用两种不同降温方法,进行吉富罗非鱼(Oreochromis niloticus)(60.13g)低温应激比较(水温从26℃降至致死温度8℃)。急性低温应激组以9℃/h的降温速度,2h后水温降至8℃;慢性低温应激组以3℃/d的降温速度,6d后水温降至8℃。以水温到达8℃时的时间为0h,比较致死温度下两种低温处理对吉富罗非鱼48h内累积死亡率、血清皮质醇与天然免疫指标的变化。结果表明,致死温度下48h时,急性低温应激组的累积死亡率为53.33%,显著高于慢性低温应激组的26.67%(P<0.05);慢性低温应激组血清皮质醇水平低于急性低温应激组,血清溶菌酶、C3和IgM活力以及头肾中C型溶菌酶和抗菌肽基因相对表达水平显著高于急性应激组(P<0.05)。急性低温应激组相对较高的血清皮质醇水平抑制了机体天然免疫活性,降低了鱼体的抵抗力。因此,在实际养殖生产中,通过适当的低温驯化过程可以有效地提高吉富罗非鱼的低温耐受性。
Genetically improved farmed tilapia （GIFT） tilapias （Oreochromis niloticus） （60.13g） reared at 26℃ were treated at 8℃ （lethal low temperature） by two kinds of low temperature stress： acute temperature stress and chronic temperature stress. Water temperature of acute stress group was reduced to 8℃ at the rate of 9℃/h, and that of chronic stress group was reduced to 8℃ at the rate of 3℃/d. Setting the beginning of water temperature at 8℃ and 0h, we examined the changes in cumulative mortality, serum cortisol and some innate immune factors under lethal low temperature over 0—48h in the tilapia. The results showed that cumulative mortality （53.33%） of acute stress group was significantly higher than that of chronic stress group （26.67%） at 48h after stress （P〈0.05）. The serum cortisol level of chronic stress group was lower than the level of acute stress group at 48h; but the activities of serum lysozyme, C3 and IgM and the level of c-type lysozyme and HAMP1 mRNA in head kidney were higher than those of acute stress group. The higher level of serum cortisol in acute stress group inhibited innate immune activity of fish body, and thus the resistance ability reduced. It is suggested that in the course of the tilapia culture, the capability of cold tolerance by the tilapia can be improved by use of cold acclimation.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2013年第4期919-925,共7页
Oceanologia Et Limnologia Sinica
基金
“十二五”农村领域国家科技支撑计划课题,2012BAD26B03-1号
关键词
吉富罗非鱼
低温应激
死亡率
皮质醇
天然免疫因子
GIFT tilapia Oreochrornis niloticus
low temperature stress
mortality
cortisol
innate immune factor
