Listed as endangered on the IUCN List of Threatened Species (IUCN, 2010). This species was first described in 1889 but had not been found for the next 100 years. It was only known from the original description (Günther, 1889). In 2005, the salamander was re-discovered near the type locality (Wang et al., 2007). Population size is probably small and declining due to construction of human infrastructures (IUCN, 2010).
The interior line of the vomerine teeth only reaches the mid-line of the eye. When limbs are adpressed, fingers and toes meet. Tubercles absent from palms and soles. 11 costal grooves in holotype (likely a juvenile) and 12 costal grooves in adults secured after 2005. Caudal fins absent. Marble-like dark spots present on venter.
2n=56, 1M, 2M, 3M, 4ST, 5SM, 6M, 7SM, 8SM, 9M, 10SM, 11SM, 12SM, 13M, 14M, 15M, 16M, 17M, 18M, m (19–28), from Qing et al. 2009.
M: metacentric; SM: submetacentric; T: telocentric; ST: subtelocentric; m: micro-chromosome
The mitochondrial sequence is available in Nishikawa et al. (2010)
This description is a summary of the new description of the two type specimens by Adler & Zhao (1990). Head large, its length longer than its width. Tip of snout rounded. Eyes dorsolateral in position, slightly protruded. Diameter of eye shorter than the distance from its anterior corner to the tip of snout; pupil rounded. Nostril between eye and tip of snout, and slightly closer to the latter. Distance between nostrils slightly larger or equal to the distance between eyes. A V shaped bulge on top of head. No labial fold; gular fold indistinct. Series of vomerine teeth U shaped. Body short and stout. Limbs well developed and tips of digits meet when limbs are adpressed. 11 costal grooves, very prominent and meeting on ventral midline. Four fingers, five toes. Digits flattened, free; without palmar and tarsal tubercles; no cornified covering on palms, tarsa, fingers and toes. Tail length shorter than snout-vent length; tail compressed, cylindrical at the base and pointed at the end, without crest on ventral edge and only slightly so on its dorsal side. Skin smooth. Color and size could not be established due to the condition of the specimens. In 2005 specimens were collected from the type locality (Gaojiayan, Yichang, Hubei Province), which largely conformed to the description by Adler & Zhao (1990) except for the shape of the vomerine teeth series. Total length was 165-205 mm, tail length a little shorter than snout-vent length. 12 costal grooves. Color was not reported, but apparently conforming to the original description of Günther (1889): uniformly black on upper parts, brownish with dark spots on underside (Wang et al., 2007).
Holotype. Total length: 85 mm; snout-vent length: 46 mm; Head length: 11 mm; Head width: 10 mm; forelimb length: 15 mm; hind-limb length: 16 mm (Günther, 1889).
Adult rediscovered after 2005. Total length: 180.8 mm; snout-vent length: 94.9 mm; Head length: 23.2 mm; Head width: 20.1 mm; forelimb length: 23.6 mm; hind-limb length: 27.5 mm (Wang et al., 2007).
Adler & Zhao (1990) suggest that Hynobius from Zhejiang and Fujian province, southeastern coast of China, are populations of Hynobius chinensis. However, Fu et al. (2003) prefer to restrict the name Hynobius chinensis to the population of the Yichang area in Hubei province, central China, and use H. yiwuensis for the Zhejiang and Fujian populations. Phylogeny derived from mitochondrial data indicates that H. chinensis is not closely related to H. yiwuensis but is the sister taxon to H. maoershanensis (Nishikawa et al., 2010). Interestingly, H. chinensis is not the sister taxon to H. guabangshanensis, which is geographically closest to the former species.
The species that was described by Günther in 1889 as Hynobius chinensis was collected in Yichang, Hubei Province (see discussion in Adler & Zhao, 1990). Until it was rediscovered in 2005 no salamanders had been reported from that area (Wang et al., 2007). There is a large gap between the distribution of H. chinensis in Hubei Province and that of the other Hynobius taxa in Zhejiang and Fujian (Fu et al., 2003). The map indicates the distribution in Gaojiayan, Yichang, Hubei Province, keeping a possible occurrence in Fujian open until more information becomes available (IUCN, 2010). The Zhejiang records are taken to refer to H. yiwuensis.