| In recent years, the economy of marine mollusc disease frequent outbroke whichrestrained the healthy development of the mollusc aquaculture. The occurrence of diseaseoften associated with environment change. Mollusc possessed non-specific immune systemwhich played an important role in the prevention of shellfish disease, however, it waseasily to be influenced by environmental factors such as water temperature and salinity.Therefore, studies on the relation between environment and mollusc immune was greatsignificant for the prevention of disease in farmed mollusc. Crassostrsea hongkongensisand hybrid abalone (Haliotis discus hannai Ino) were chose the object of study, and theimpact of mollusc immune activity by changing of environmental factors was studied, thispaper aims to provide scientific basis for Crassostrsea hongkongensis and hybrid abalone(Haliotis discus hannai Ino) disease prevention and treatment. The results were as follows:1. The effects of salinity stress on the immune parameters of Crassostrea hongkongensisThe influence of abrupt salinity change from18to3、25、40on the nonspecificimmune factors was studied.After24h and48h, superoxide dismutase (SOD), alkalinephosphatase (AKP), catalase (CAT) and lysozyme (LZM) of Crassostrea hongkongensishemolymph were examined. Results indicated that the change of four immune factors werenot significant (P>0.05) compared with the control (18). AKP and LZM vitality of salinity25group were significantly higher than those in the control (P<0.01) at the24th.The SODactivity of salinity3group was significantly higher than the control (P<0.01) at the24hth.Other groups showed no significant difference compared with the control. The SODactivity of salinity40group was significantly lower than the control (P<0.01) at24hth,LZM activity was no significant difference compared with the control at24hth, but it wassharply decline and significantly lower than the control (P<0.01) at48hth.2.The effects of salinity stress on the immune parameters of Hybrid abalone：Haliotisdiscus hannai InoChanges of hemolymph superoxide dismutase (SOD), alkaline phosphatase (AKP),catalase (CAT),lysozyme (LZM) and bactericidal activities(Ua) were studied when thesalinity stepwise changed from34to16、22、28、40within48h. The results showed that the change of five immune factors was not significant (P>0.05) at salinity28,34(the control)during the experiment. In salinity40group, AKP vitality was significantly lower than thecontrol (P<0.05) throughout the experiment, CAT vitality significantly higher than thecontrol at first and then gradually decreased, significantly lower than the control (P<0.05)at last. The LZM vitality declined and gradually stabilized at a significantly lower valuethan the control (P <0.05) at last. In salinity22group, AKP activity showed a downwardtrend, and significantly lower than the control (P<0.05) at the48hth. In salinity16group,SOD, AKP, LZM activity and bactericidal activities showed a downward trend,significantly lower than the control (P <0.05) at the48hth, CAT vitality was significantlylower than the control (P<0.05) in all time.3. The effects of water temperature stress on the immune parameters of hybrid abalone：Haliotis discus hannai InoThe change of the hybrid abalone hemolymph superoxide dismutase (SOD), catalase(CAT), alkaline phosphatase (AKP), lysozyme (LZM) vitality and antibacterial vitalitywere studied when the temperature gradually changed from18℃(the control group) to6℃,12℃,24℃and30℃. The results showed that the five immune factors were notsignificantly different compared with the control group at the12℃and24℃group. In the6℃, the antibacterial activity was significantly lower than the control (P<0.05) at the48hth,and there were not significantly different in other groups compared with the control group,In the temperature30℃group, in all experiment, SOD, AKP, LZM and antibacterialvitality (Ua) of hybrid abalone were significantly lower than the control (P<0.05), CATactivity gradually increased after the24hth, and significantly higher than the control groupat last. The results showed that the higher or lower temperature stress significantlyinfluenced the activity of the hybrid abalone immune factors, the vitality of hybrid abaloneimmune factors would be significantly affected when the temperature higher than30℃and less than6℃.4. Change in water temperature on the immunity response of Hybrid abalone Haliotisdiscus hannai Ino and its susceptibility to Vibrio harveryiThe change regular of the hybrid abalone hemolymph total haemocyte counts(THC),the relative proportion of blood cells (H=percentage of granulosa cells: the percentage ofhyalinocyte), superoxide dismutase (SOD), catalase (CAT), alkaline phosphatase (AKP),lysozyme (LZM) vitality, antibacterial vitality and mortality rate were studied when the water temperature gradually changed from18℃(the control group) to12℃,24℃and30℃after infected by Vibrio harveyi. The results showed that hybrid abalone mortalityincreased with increased temperature. THC, SOD, CAT, AKP, LZM and antibacterialactivity of12℃,18℃,24℃group increased, the increase rate was24℃>18℃>12℃,there was a downward trend of six indicators in the30℃group. The value H of12℃,18℃,24℃group at first less than the standard value (1.11).The results indicted that the change of salinity and water temperature significantlyinfluenced Crassostrea hongkongensis and hybrid abalone immune activity. High salinitystress could cause the oyster immune factor activity reduced significantly, but the lowsalinity had no significant influence. Hybrid abalone immune factors activity wassignificantly inhibited by low salinity and high temperature, however, high salinity and lowtemperature stress had no significant impact on the activity of hybrid abalone immunefactors. The paper results showed that different mollusc had different immunomodulatorymechanism to deal with external environmental factors stress, and thus adapted to differentculture environment. |
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