Batrachuperus londongensis Liu and Tian in Liu, Hu, Tian and Wu, 1978
Listed as endangered on the IUCN Red List of Threatened Species (IUCN, 2010). Major threat comes from over-harvesting for food and traditional Chinese medicine. Eating the salamander is believed to promote bone healing and boost stamina. Habitat is being destroyed because local people use stones in the river to build dams (Fei et al., 2006). The salamander needs underwater stones to hide and attach egg sacs to.
This species is among the largest in the genus, reaching 155–265 mm in total length. Palms and soles are covered by horny coverings. Many sexually-mature adults still possess gill slits or gill residues, which is a sign of neoteny.
The mitochondrial genome has been sequenced by Zhang et al. (2006). Allozyme data have been collected by Fu & Zeng (2008).
Batrachuperus londongensis looks similar to B. pinchonii in coloration and the presence of horny covering on palms and soles but differs from the latter by a larger body size and the presence of neoteny. The egg sac is larger and longer in B. londongensis (200 mm) than in B. pinchonii (65–85 mm). The two species co-exist in Mount Omei in Sichuan.
Batrachuperus londongensis is a large, robust salamander with a flattened head, longer than wide, with short rounded snout. Eyes prominent, projecting laterally. Labial fold well developed, partly covering lower jaw. Two grooves present posterior to the eye: one stops at the angle of the jaw, the other at the gill slit. It was described on the basis of exceptionally large-bodied individuals in a population on Mount Omei, which show a tendency to neoteny: Many adults have remnants of gills or open gill slits. Among the 70 adult specimens examined by Fei et al. (2006), 2/3 have gill slits or gill remnants at least at one side of the head. The following description is a summary of the species entry in Fei et al. (2006). Body slightly flattened with 12-13 costal grooves (rarely 14); tail thick and cylindrical at the base, more flat toward the tip. Limbs short and thick; when adpressed there are one to three costal grooves between fingers and toes. No interdigital webbing. Dark horny cover on limbs, especially on toes and digits. Tubercles on palms and soles are absent or only small. In the male, the vent is a transverse crescentic opening with a light-colored papilla in the middle. The vent of the female is a longitudinal opening. Color black-brown on the back and sides; some individuals have irregular brown-yellow or orange-yellow spots on the body. Throat light purple-gray, underside purple-gray with irregular black-blue spots.
All measurements are from Fei et al. (2006).
Male (20 specimens). Snout-vent length: 75.8–118 mm; tail length: 74.2–112 mm; Head length: 19.7–28.9 mm; Head width: 15–24.5 mm.
Female (10 specimens). Snout-vent length: 84–114.4 mm; tail length: 77–105 mm; Head length: 20.4–26 mm; Head width: 14.2–20 mm.
Batrachuperus londongensis was considered a synonym of B. pinchonii by Zhao & Jiang (1988) and Zhao & Adler (1993), but was resurrected by Ye et al. (1993). The two species share the presence of extensive horny covering on palms and soles, which is absent in congeners. And the two species co-occur in Mt. Omei. Zhang et al. (2006) found a possible sister relationship between B. londongensis and B. pinchonii based on complete mitochondrial genome. However, a denser sampling of the whole genus suggests that the two species are not closely-related (Fu & Zeng, 2008).
Previously, only a single population in Longdong River (Mount Omei, Sichuan, China, from 1300 to 1800 m altitude) was considered to be B. londongensis (Fei et al., 2006), but a molecular study identified most populations from Mount Omei – except from the summit – and Mount Wawushan in nearby Hongya County, and Mount Nibashan in Hanyuan County as B. londongensis. All of these populations were previously identified as B. pinchonii (Fu & Zeng, 2008).
Inhabits deeper parts in lower section of rivers and springs in forested areas. Stones to hide under and stick egg sacs to are crucial elements in the habitat (Fei et al., 2006).
One egg sac found in pieces could be recovered, around 20 cm long. Largest eggs found in a female’s ovary were 3.5-4.0 mm. According to local spokesmen larvae hatch around April (Fei et al., 2006).