Batrachuperus taibaiensis Song, Zeng, Wu, Liu and Fu, 2001
Conservation status and population data are not known for this species. However, a study from WWF China suggests that a water transfer project (using tunnels to transfer water from one river to another to supply nearby cities) has threatened this species by pollution from the construction work and habitat change caused by water transfer (http://www.wwfchina.org/aboutwwf/whatwedo/species/davidianus.shtm).
A relatively large, robust salamander; distinguished from other members of the genus by its large size, vomerine teeth arranged in inverted V shape, and lack of horny cover on palms and tarsa. Batrachuperus taibaiensis is distinguished from geographically neighboring species B. tibetanus by its larger size and the arrangement of vomerine teeth (the description above is a summary of Song et al., 2001).
Mitochondrial and allozyme data are available from Fu et al. (2001) and Fu & Zeng (2008).
This species looks like B. londongensis. Both species share the large body size (males over 217 mm in total length) and the inverted V-shaped vomerine teeth. Batrachuperus taibaiensis differs from B. londongensis by the lack of horny covers on palms and soles and absence of neoteny.
Batrachuperus taibaiensis is a large, stout salamander. Head moderately depressed, longer than wide; snout short and rounded. Labial fold well developed, partially covering lower jaw. Eleven costal grooves. Limbs relatively short but strong; when adpressed, tips of digits do not overlap and are always separated by 1-3 costal grooves in adults. Most individuals without palmar and tarsal tubercles. No horny covers on palms, tarsa, and ventral side of fingers and toes. Some individuals have a horny cover on tips of digits. Tail round at the base and gradually flattening laterally. Tail fin moderately high. Snout-vent length a little longer than tail length in males, about the same in females. Color dark or olive gray on the back, sometimes with small dark spots, the underside is light gray (Song et al., 2001).
All measurements are from Song et al. (2001).
Male (11 specimens). Snout-vent length: 73–110 mm; Tail length: 76–115 mm; Head length: 20–29 mm; Head width: 18–23 mm; forelimb length: 20–27 mm; hind-limb length: 25–36 mm.
Female (9 specimens). Snout-vent length: 94–111 mm; Tail length: 91–113 mm; Head length: 25–28 mm; Head width: 19–25 mm; forelimb length: 22–26 mm; hind-limb length: 23–34 mm.
The validity of Batrachuperus taibaiensis is questioned by Fu & Zeng (2008) because the allozyme data suggest that this species shares a nuclear gene pool with B. tibetanus. However, uncorrected mitochondrial divergence is 7–10% between the two species. Moreover, the mitochondrial phylogeny places B. taibaiensis with B. karlschmidti. The closest distance between populations of B. taibaiensis and B. tibetanus is 50 km without apparent geographic barrier; it is hard to explain the presence of two very divergent mtDNA lineages in one species in such close proximity (Fu & Zeng, 2008). More data are needed to evaluate the validity of B. taibaiensis.
Batrachuperus taibaiensis is known from the type locality at the upper stream of the Heihe River, Zhouzhi County, Shaanxi Province, China, at 1,260 m altitude. It is believed to range throughout the area of Taibeishan Mountain in Shaanxi (IUCN, 2010), and thought to extend to Gansu and northern Sichuan (Zeng, 2004). Li et al. (2008) studied the salamanders in the upper part of two rivers and their associated streams on the northern and southern sides of Ping He Liang, from 1,800 to 2,000 m altitude.
Like other species of Batrachuperus, B. taibaiensis inhabits fast flowing streams and can be found under rocks in the stream and on the banks. Subalpine conifers characterize the surrounding habitat, with vegetation often hanging over rivers and streams. In the same streams Liua tsinpaensis was found; Batrachuperus pinchonii was wide-spread at lower elevations near the Tsinling Mountains, where B. taibaiensis was studied by Li et al. (2008).
The breeding season most likely occurs from April to July, as the youngest larvae with gills and the highest number of juveniles in different stages of development were collected in early August (Li et al., 2008). Egg sacs, coiled and 15–17 cm long, were found attached to the underside of rocks in April, each containing 27–29 eggs. The egg sac is a C-shaped cylindrical tube with tapered ends. It is nearly transparent with longitudinal striations. At the free end of the egg sac is a soft cup-like cap. Egg diameter was given as 5.0–5.5 mm. Free swimming larvae were found at stream edges under small stones in the beginning of August. Labial fold and lateral lines are well developed in larvae. There are four pairs of external gills. Forelimb is fully developed with four fingers (Li et al., 2008).