The effect of incubation temperature on egg survival, hatchling traits and embryonic use of energy in the blue-tailed skink, Eumeces elegans

Abstract

Abstract Eggs of the skink, Eumeces elegans were incubated at 24, 27, 30 and 33°C to assess the effect of temperature on hatchling traits and embryonic use of energy. The mean incubation periods of eggs incubated at 24, 27, 30 and 33°C were 44.1, 28.0, 23.6 and 20.0 days, respectively. The mortality of embryos incubated at these temperatures did not differ significantly. The mean snoutvent lengths of hatchlings from 30 and 33°C were smaller than those of hatchlings from 24°C. In contrast, the body masses of hatchlings were not affected by temperature. Incubation temperature can also modify limb lengths of hatchlings. The fore and hind limb lengths of hatchlings from 24°C were longer than those of hatchlings from 33°C. However, tail length and head size (length and width) for hatchlings from different temperatures were similar. The locomotor capacity of hatchlings incubated at 33°C was completely destroyed, whereas that of hatchlings from the other three temperatures did not differ significantly in spite of the existence of differences in hatchling size. Moreover, incubation temperature affected the allocation of energy between carcass and yolk sac in the hatchling, although the overall conversion of energy from eggs to hatchlings was not influenced by temperature. Hatchlings from 30 and 33°C had a less developed carcass and more energy in yolk sac than those from 24°C. Thus, we can conclude that 33°C is not suitable for the incubation of E. elegans eggs, due to damage to the embryo.