Reproduction, Development, and Growth Response to Captive Diets in the Shangcheng Stout Salamander, Pachyhynobius shangchengensis (Amphibia, Urodela, Hynobiidae)

Abstract

The Shangcheng stout salamander (Pachyhynobius shangchengensis) is a poorly known stream dwelling hynobiid salamander from China. We studied the reproduction, development and growth response of the salamander to different diets in captivity. Two females each produced two unique, striated egg sacs, with each containing 18 and 20, and 22 and 32 white eggs with an average diameter of 3.3 mm. Hatchlings (n = 27) had front- and hind-limb buds with interdigit membranes and a large yolk sac, and developed cornified finger and toe tips during further development. Metamorphosis occurred between d 441 and d 454 after hatching at an average total length of 94.8 mm (n = 21). These reproductive and developmental traits fit in well with the ancestral state reconstruction in hynobiids. If corrected for dry mass, feed conversion ratios obtained by feeding bloodworms (Chironomidae) to R shangchengensis larvae and mealworms (Tenebrio molitor) to postmetamorphs, were very low (0.33 and 0.34 respectively), equaling a very high mass conversion efficiency.