产卵于温暖且热稳定巢内的蜥蜴具有相对较高但较窄范围的孵化温度

作者用蜡皮蜥(Leiolepis reevesii)为模型动物,检验产卵于温暖且热稳定巢内的蜥蜴应有相对较高但较窄的孵化温度的假设。卵在三个恒定温度(27、30和33℃)、一个波动温度处理下孵化。温度的平均值而非方差影响孵化期,27、30和33℃的平均孵化期分别为101.1、69.6和55.3d。幼体性别不受孵化温度影响。不同处理孵出的幼体仅有稍许形态差异,但运动表现差异显著。27℃孵出幼体在跑道上的表现比其它处理孵出幼体差。卵能在27℃和33℃下孵化,但这两个孵化温度并不适宜。蜡皮蜥适宜的孵化温度范围可能处于最频繁的巢温变化范围(28℃-32℃)内。与其它在低温生境或温暖生境但产卵于浅巢的有鳞类爬行动物相比较,蜡皮蜥有相对较高但较窄适宜的卵孵化温度。因此,作者的数据支持上述假设。

Relatively high but narrow incubation temperatures in lizards depositing eggs in warm and thermally stable nests

We used the Reevese's butterfly lizard Leiolepis reevesii as a model animal to test the hypothesis that incubation temperatures should be relatively high but narrow in lizards depositing eggs in warm and thermally stable nests. Eggs were incubated under three constant (27, 30 and 33℃) and one fluctuating temperature regimes. Hatchability was highest at 30℃ and lowest at 27℃. The mean rather than the variance of temperatures affected incubation length, and the mean incubation length was 101.1 days at 27℃, 69.6 days at 30℃ and 55.3 days at 33℃. Incubation temperature did not affect the sexual phenotype of hatchlings. Hatchlings from different treatments showed little variation in morphological phenotypes, but differed significantly in locomotor phenotypes. Hatchlings incubated at 27℃ performed much more poorly in the racetrack than did hatchlings from the other three treatments, and the variance of incubation temperatures negatively affected sprint speed of hatchlings. The incubation temperatures of 27℃ and 33℃ supported egg incubation, but these two temperatures were not ideal. The range of temperatures suitable for incubation of L.reevesii eggs presumably lies between the range of nest temperatures varying most frequently from 28℃ to 32℃. Compared with results reported for other squamate reptiles either from cool habitats or from warm habitats but depositing eggs in shallow nests, temperatures suitable for egg incubation are relatively high but narrow in L.reevesii. Thus, our data validate the above hypothesis[Acta Zoologica Sinica 53(3):437-445,2007].