| In this paper, I made slow heating experiments and rapid heating experiment usingexperimental physiology, ecology, histologicl and molecular biological, with differentspecifications, different shell color, and different family of M.yessoensis to tested the survivalrate, oxygen consumption rate, ammonia excretion rate, and immune parameters variation, andthen analysis the expression of HSP70at different temperatures, and have histologicalobservation of the gill tissue of M.yessoensis at high temperature.(1)In this study, we tested the high temperature mutation tolerance, survival, oxygenconsumption rate, ammonia excretion rate and immune enzyme activity under different hightemperature level of M.yessoensis. The survival of M.yessoensis was not affected by temperaturefrom15℃to22℃with survival rate exceeding85.21%, and there is no significant difference indifferent group (P＞0.05). Scallops exposed to26℃were significantly affected by temperature,with a survival of26.33%. With the temperature rising, the T-AOC and MDA content In thebody cavity fluid of M.yessoensis significantly changed (P＜0.05). The CAT vitality would riseafter the first drop with the rise of temperature. There were no significant differences amongdifferent groups’ SOD vitality (P＞0.05). Secondly, we abruptly transferred scallops from therearing temperature (15℃, control temperature) to20、22、24and26℃level, and examinedrelated immune index in the presence of1,2,4,8,12,24,48and96h. The results showed that,the survival of M.yessoensis was not affected by temperature from15℃to24℃during the96hexposure periods with survival rate exceeding82.29%. Scallops exposed to26℃weresignificantly affected by temperature, with a survival of0after12h. The8,12,24,48and96hlethal temperature for50%(LT50) were27.52,24.41,24.37,24.24and23.81℃respectively. Inaddition, the CAT and T-AOC in the coelomic fluid of M.yessoensis changed significantly afterhigh temperature stress (P＜0.05), among all the groups, the22,24and26℃treatment groupreached to the highest level after8h of stressing, and then turn back to the control group level,however, the content of MDA and SOD vitality had no obvious difference with the controlgroup with the extension of stressing time. Detected the different expression of HSP70ofM.yessoensis used RT-PCR under high temperature. The results showed that, the HSP70expression was highest in gill when the suitable temperature conditions about M.yessoensis, in15℃. The HSP70expression of mantle increased significantly at24℃and26℃(P＜0.05), andreached highest expression level at26℃.The HSP70expression of gill was increasedsignificantly at24℃(P＜0.05), and there were significantly difference from24℃to26℃(P＜0.05).The HSP70expression of adductor muscle was increased significantly to the highest at26℃(P＜0.05). There were no significant difference from15℃to24℃(P＞0.05). A temperaturecontrolled indoor experiments to study the impact of gill of M.yessoensis under high temperature.The results showed that, the lamella structure of M.yessoensis is divided into branchial filaments,interfilamentary junction, canal, and interlamellar junction. The thickness of lamella was significantly reduced from15℃to24℃(P＜0.05). The width of branchial filamentssignificantly smaller from15℃to20，22and26℃(P＜0.05). The interfilamentary junctionsignificantly reduced friom15℃to22and26℃(P＜0.05). There were no significant differenceof small gill cavities and interlamellar junction from15℃to20℃(P＞0.05), and significantlyexpand at24℃(P＜0.05).(2)In the study, I tested survival rate, oxygen consumption rate, ammonia excretion rate,and immune parameters variation of2different specifications of M.yessoensis under hightemperature. The results showed that the large shell is better than small shell under hightemperature. The survival of M.yessoensis was not affected by temperature from15℃to22℃with survival rate exceeding90%, and there is no significant difference in different group (P＞0.05), but the survival of large shell was significantly higher than small shell at28-30℃(P＜0.05). The small shell increased metabolism with increasing temperature from15℃to24℃and decreased at26℃, the large shell continued increasing metabolism from15℃to26℃，andlower at26℃. The immune parameters was increased and then decreased trend with increasingtemperature, large shell and small shell reached the highest value at26℃and24℃,respecitively.(3) In the study, I tested survival rate, oxygen consumption rate, ammonia excretion rate,and immune parameters variation of M.yessoensis from different shell color. The results showedthat, the survival of M.yessoensis was not affected by temperature from15℃to22℃withsurvival rate exceeding90%, and there is no significant difference in different group (P＞0.05),but the “maple-leaf-shell” significantly reduced compared with the other two(P＜0.05). As thetemperature increases, the oxygen consumption rate and ammonia excretion was siginificantlyincreased from15℃to24℃, but decreased significantly at26℃(P＜0.05). In addition, theT-AOC, CAT, SOD, and POD activity increased and then decreased trend with increasingtemperature, and reached the highest value in24℃, and decreased significantly at26℃.(4) In the study, I tested survival rate, oxygen consumption rate, ammonia excretion rate,and immune parameters variation of M.yessoensis from different family. The results showed that,three families of more than half of the deaths at29℃. At that time, M.yessoensis from w1hadthe highest survival rate of63%, followed by w5, whose survival rate was57%, butM.yessoensis of wr2had the lowest survival rate,10%.The CAT, T-AOC, and POD activitychanged significant(P＜0.05) from different families, and there were no significant difference atSOD vitality. Thus, the white shell family showed strong resistance to high temperatures. |
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