不同发育期大蟾蜍幼体的热适应

Thermal adaptation of the common giant toad(Bufo gargarizans) at different earlier developmental stages

为了解大蟾蜍幼体的热适应特性,并验证最适性模型,应用温度梯度槽对不同发育期大蟾蜍幼体的最适温度、最高逃避温度和最高致死温度进行了研究。大蟾蜍蝌蚪期的最适温度为(15.77±2.21)℃,变态期为(24.26±2.88)℃,幼体期为(27.62±2.58)℃。在每一个发育期,幼体都有2个最适温度峰值,这一结果与最适性模型的预测完全一致。不同发育期大蟾蜍幼体的最适温度存在显著性差异(F=282.521,P<0.001,df=2,N=150)。蝌蚪期的最高逃避温度为(32.45±1.25)℃,变态期为(35.11±1.29)℃,幼体期为(37.83±1.72)℃。不同发育期大蟾蜍幼体的最高逃避温度间存在显著差异(F=119.585,P<0.001,df=2,N=90)。蝌蚪期的最高致死温度为(36.56±1.3)℃,变态期为(38.45±1.53)℃,幼体期为(39.96±1.39)℃。不同发育期大蟾蜍幼体的最高致死温度存在显著差异(F=35.372,P<0.001,df=2;N=60)。

In order to study the thermal adaptability of the common giant toad （Bufo gargarizans）, and to test the optimality models, preferred temperatures, high avoidance temperatures and lethal thermal maxima of this species at different earlier developmental stages were measured against an artificial thermal gradient. The preferred temperature of the animals at tadpole stage was （ 15.77 ± 2.21 ） ℃ , at metamorphosis stage was （24.26± 2.88） ℃ , young toad soon after metamorphosis was （27.62 ± 2.58）℃. There were two higher peaks in the preferred thermal intervals of the subject animals at all these.stages, which is consistent with the prediction of the optimality models to a great extent. There were significant differences between the preferred thermal intervals of animals at different earlier developmental stages （F = 136.222, P 〈 0. 001, df = 2, N = 150）. The high avoidance temperature of the animals was （32.45± 1.25） ℃ at the tadpole stage, （35.11±1.29） ℃ at the metamorphosis stage, and （37.83 ±1.72）℃ at the young toad stage soon after metamorphosis. There were significant differences between the high avoidance temperatures of the animals at different earlier developmental stages （F = 119.585, P 〈0.001, dr=2, N = 90）. The lethal thermal maximum of the animals was （36.56 ± 1.3）℃ at the tadpole stage, （38.45 ± 1.53）℃ at the meta- morphosis stage, and （39.96± 1.39）℃ at the young toad stage soon after metamorphosis. There were significant differences between the lethal thermal maxima of the animals at different earlier developmental stages （F=36.106, P〈0.001, df=2, N=60）.