镇海棘螈早期个体发育研究

The Preliminary Studies on the Early Development of theChinhai Salamander, Echinotriton chinhaiensis

根据野外观察和室内实验 ,对镇海棘螈的早期个体发育过程进行了研究。结果显示 ,镇海棘螈早期发育过程与琉球棘螈的个体发育过程非常相似 ,它们的平衡枝均不发达且在前肢芽晚期迅速消失。温度和湿度对胚胎发育具有显著影响。室温下 ,从受精卵到孵化需 2 9d左右。孵化幼体体长呈配合对数曲线增长 ,其体全长 (S)与日龄 (T)的关系可表示为S =1 2 974 9+6 2 398lnT(Sig.F <0 0 1 )。水生生活阶段为 58～ 88d。室内幼体的水生发育时间和变态个体大小与野外的情况有较大的差异 ,可能与营养条件和自然条件下的持续干旱有关。变态前的外鳃萎缩期是镇海棘螈早期个体发育过程中的死亡高峰期。

According to the observation and experiments in the laboratory and in the field, the early developmental pattern of the Chinhai salamander is gotten. The results showed that: the early development stage of Chinhai salamander, E.chinhaiensis, is very similar with its relative species, E.andersoni(Utsunomiya and Utsunomiya, 1977). Their balanceres are poorly developed and disappear very early. Temperature and moisture significantly influence the embryonic development of the Chinhai salamander. Although the eggs only were deposited on land in nature, the embryos can developed both in water and on land. No significantly different was found between the hatching ratios in water and on land. The range of embryonic period is positive related to the water level covering the embryos. For the embryos hatching on land, the embryonic stage is approx. 29 days under room temperature. The growth curve can be expressed with a logarithmic curve, S=12.9749+6.2398 ln T,S and T express the total length and age of larvae, respectively. The larvae stage in water is approx. 58～88 days. Many internal and external factors influence the early normal development of Chinhai salamander.