恒定和波动温度下丽斑麻蜥孵出幼体的表型变异

作者以丽斑麻蜥(Eremias argus)为模型动物研究恒定和波动孵化温度对孵化成功率和孵出幼体表型的影响。卵在四个恒定[24 ,27 ,30 and 33 (±0·3)℃]、一个波动温度下孵化。不同温度处理下的孵化成功率相同,但孵出幼体表型不同。孵化期随孵化温度升高呈指数式缩短;在相同平均温度下,波动温度孵化卵的孵化期比恒温孵化卵长。在所有被检表型特征中,幼体的干重、剩余卵黄干重和运动表现更易受孵化温度影响。总体而言,低温(24℃、27℃)孵出幼体运动表现最佳,高温(33℃)孵出幼体最差、温和温度(30℃和波动温度)孵出幼体居中。本文研究数据显示: (1)丽斑麻蜥卵每日短期暴露于潜在致死的极端温度下对孵化成功率和孵出幼体形态特征无明显的不利效应; (2)温度波动对孵出幼体运动表现无促进作用,对孵化期的影响则不同于平均值相同的恒定温度。

Phenotypic variation in hatchling Mongolian racerunners Eremias argus from eggs incubated at constant versus fluctuating temperatures

We used the Mongolian racerunner Eremias argus as a model animal to evaluate the effects of constant versus fluctuating incubation temperatures on hatching success and hatchling phenotypes. Eggs were incubated under four constant [24, 27, 30 and 33 ( ± 0.3)℃ ] and one fluctuating temperature regimes. Hatching success did not differ among treatments, and incubation temperature did not affect the sexual phenotype of hatchlings. Incubation length decreased exponentially as incubation temperature increased, and eggs incubated at fluctuating temperatures took a longer time to complete development than did those incubated at constant temperatures with the same mean. Of the hatchling phenotypes examined, body dry mass, carcass dry mass, residual yolk dry mass and locomotor performance of hatchlings were more likely to be affected by incubation temperature. Overall, locomotor performance was best in the low temperature treatments (24℃ and 27℃ ) and worst in the highest temperature treatment (33℃), with the moderate temperature treatments (30℃ and fluctuating temperatures) in between. Our data show that: (1) daily exposure of eggs to extreme temperatures that are potentially lethal to embryos for brief periods does not have detectable adverse effects on hatching success and morphological phenotypes in E. argus; and (2) thermal fluctuations exert no positive effects on locomotor performance of hatchlings but influence incubation length differently than constant temperatures with the same mean [ Acta Zoologica Sinica 52 (6): 1049-1057, 2006].