The Breeding Ecology of a Critically Endangered Salamander,Hynobius amjiensis(Caudata:Hynobiidae),Endemic to Eastern China

Hynobius amjiensis is a critically endangered salamander species（IUCN Red List） endemic to eastern China. It currently has three known populations: one in Longwangshan, Zhejiang Province（type locality）, and two in Qingliangfeng between Anhui and Zhejiang Provinces. We examined the relatively unstudied breeding ecology of this species in the field and at laboratory from March 2007 to May 2014. Adult males and females were year-round terrestrial, except for the February–April breeding season. During this period, we captured only a total of 16 breeding adults（11 males and 5 females）. As few as 100 breeding females were estimated based on the number of egg sacs observed since 2007. This number was significantly reduced from the estimated number between 1992 and 1998. Males（mean total length = 16.21 cm, mean body mass = 18.8 g） were slightly smaller than females（16.51 cm, 19.2 g）. Size of breeding pools ranged from 0.2 m;to 1.2 m;（0.1–1.2 m depths）. Each female deposits a pair of egg sacs by attaching the adhesive tips of the sacs to aquatic plants or dead twigs. Fifteen pairs of egg sacs had an average length of 28.6 cm and a diameter of 3.3 cm. On average, each egg sac contained 75 eggs with a diameter of 0.3 cm. Our field survey revealed that H. amjiensis used oviposition sites in small, cool, and weakly acidic pools at high elevations（1 300–1 600 m） where peat moss was abundant. Reduction in wetland size and disappearance of suitable breeding pools suggest that this salamander species is under threat of extinction, particularly at Longwangshan, where 5 of the 9 breeding pools have either dried up or disappeared. Combined size of the remaining 4 pools is less than 2 m;. We urge immediate implementation of more effective conservation measures and suggest that preservation priority should be given to habitat that contains suitable breeding pools.