In this study, two experiments were conducted to investigate the effects of high temperature on survival, oxygen consumption and ammonia-N excretion of yesso scallop Mizuhopecten yessoensis. In the first experiment, the yesso scallop held at water temperature of 15 ℃ (as control) were abruptly transferred to 20,22,24 and 26 ℃, and the survival were observed at exposure of 8,12,24,48 and 96 h. In the second experiment, the scallop were acclimatized to the different water temperature (20,22,24 and 26℃) and then maintained for 7 days. The results showed that the yesso scallop had survival of 82. 29% at sudden change in water temperature from 15℃ to 24℃ during the 96 h exposure periods in the first experiment, without significant differences during various exposure periods (P>0. 05). However, the scallop exposed to 26℃ showed survival rate of 0 after 12 h exposure, significantly lower, and with 8,12,24,48 and 96 h lethal temperature for 50% (LT50)of 27.52,24.41,24.37,24.24 and 23. 81 ℃, respectively. In the second experiment, the survival(26. 13% ) was significantly lower at 26 X than at other temperature, the peak survival(100% ) at 15℃. Furthermore, high temperature led to significant influence on the oxygen consumption and ammonia-N excretion (P<0. 05) , with the maximal oxygen consumption rates at 22 ℃, and the maximal ammonia-N excretion rates at 20℃. The relationship between temperature (t) and oxygen consumption rate(R0)or ammonia excretion rate ( Rn ) were described as R0 = -0. 1976t2 + 1. 2531t-0. 4885 (R2 = 0. 973,n=15)and RN = -0. 7373t2 +4. 5917t-1. 3133(R2=0. 8047,n=15) Respectively.%在实验室条件下研究了虾夷扇贝Mizuhopecten yessoensis对温度突变的耐受能力以及在不同高温水平下的存活率、行为、耗氧率和排氨率.试验Ⅰ:将在15℃下暂养的虾夷扇贝分别直接放到20、22、24、26℃的海水中,并在1、2、4、8、12、24、48、96 h时测定虾夷扇贝的存活率.试验Ⅱ:将在15℃下暂养的虾夷扇贝分别驯化到20、22、24、26℃,然后饲养7d,测定虾夷扇贝的存活率、耗氧率和排氨率.结果表明,在试验Ⅰ温度突变过程中,经96 h胁迫,15 ～24℃处理组虾夷扇贝的存活率均高于82.29％,且组间无显著性差异(P＞0.05),但26℃处理组的虾夷扇贝经12 h胁迫后,其存活率便降为0；虾夷扇贝在8、12、24、48、96 h的半致死温度(LT50)分别为27.52、24.41、24.37、24.24、23.81℃.在试验Ⅱ温度缓升阶段,26℃处理组虾夷扇贝的存活率最低(26.13％),15℃处理组的存活率最高(100％),15～22℃处理组的存活率均高于85％,且组间无显著性差异(P＞0.05)；温度对虾夷扇贝耗氧率和排氨率均有显著性影响(P＜0.05),22℃处理组的耗氧率最高,20℃处理组的排氨率最高,温度(t)与耗氧率(Ro)之间的相关方程为Ro=-0.1976t2+1.2531t-0.4885(R2=0.973,n=15),温度(t)与排氨率(RN)之间的相关方程为RN=-0.7373t2+4.5917t-1.3133(R2 =0.8047,n=15).
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