厚壳贻贝在不同温度下的干露耐受性研究

Study on enduring exposure and desiccation ability of Mytilus coruscus in different temperature and humidity conditions

为了解不同温度及保湿与干燥状态下厚壳贻贝稚贝的耐干露能力,分别在低温1℃、2℃、4℃和8℃,高温30℃、32℃和34℃的保湿和干燥条件下,测定壳长为(4.43±0.76)mm和(10.16±0.43)mm稚贝的耐干露能力。结果表明:1)在相同湿度条件下,厚壳贻贝稚贝干露后存活率与干露时间呈显著负相关(P<0.05)。1℃~8℃条件下,厚壳贻贝干露半致死时间长达45~91 h,而温度为30℃~34℃时,干露的半致死时间为17~23 h,低温时的耐干露能力是高温时的3倍以上。2)大规格稚贝的耐干露能力优于小规格稚贝。小规格厚壳贻贝4℃组的半致死时间为70~79 h,大规格4℃组的半致死时间为76~91 h。3)稚贝在保湿条件下的存活率明显高于干燥条件(P<0.05)。4)低温干露后,返水缓变温处理组的厚壳贻贝存活率显著高于急变温处理组,而高温干露后则情况相反。综上所述,以4℃保湿干露为厚壳贻贝稚贝的最佳运输条件,可保证24 h内90%以上的存活率。

In order to understand the tolerance of Mytilus coruscus to dry exposure in different temperature and humidity or dry conditions, we measured the juvenile with the shell length of （4.43±0.76）mm and （10.16±0.43）mm.The experiments were performed at low temperature （1℃,2℃, 4℃ and 8℃） and high temperature （30℃, 32℃ and 34℃） with the condition of being dry and moist, respectively.The results showed that the survive rate of juveniles after exposure and desiccation had a negative correlation with the time of the tolerance under the same humidity （P〈0.05）.And the semilethal time was 45-91 h at 1-8℃, while 17-23 h at 30-34℃.The endurance of juveniles to exposure and desiccation under low temperature was more than triple under high temperature.The ability to survival of large size of M.coruscus was stronger than that of the small size one.The semilethal time of small size juveniles was 70-79 h, while the semilethal time of lager size was 76-91 h at 4℃.The survival rate of M.coruscus under moisturizing conditions is higher than that in drying conditions （P〈0.05）.The survival rate about the group of rewet with slow change in temperature was higher than the quick change in temperature group after air expose in low temperature, but the result after high temperature exposure was the opposite.Research results that the optimal transportation condition of Mytilus coruscus was air exposured under moisture condition at 4℃.In this way, the survival rate could be guaranteed more than 90% in 24 h.