Batrachuperus karlschmidti Liu, 1950
Listed as vulnerable in IUCN (2010). The distribution is small. But the salamander is abundant in its range. Current threat includes habitat loss and usage as traditional Chinese medicine (powder of dried animals is used to cure stomach problems).
Labial fold is well developed. Vomerine tooth patches are widely separated. The distance between the two patches reaches 2/3 of the full length of the vomerine tooth patch. The biggest difference from congeners is the absence of spots or marblings on the body. The salamander is uniformly black to neutral grey (Liu, 1950). However, Fei et al. (2006) and Fu & Zeng (2008) suggest that the presence or absence of spots is not a good character for species delimitation.
Karyotype:
2n=68, 1M, 2M, 3M, 4ST, 5ST, 6ST, 7ST, 8ST, 9ST, 10ST, 11ST, 12ST, m(13–34), from Yang (1992).
M: metacentric; SM: submetacentric; T: telocentric; ST: subtelocentric; m: micro-chromosome
Mitochondrial sequence and allozyme data see Fu et al. (2001) and Fu & Zeng (2008).
Fei et al. (2006) suggest that a small number of specimens of B. karlschmidti from the type locality (Luhuo County) do have obvious spots and are therefore hard to distinguish from B. tibetanus.
Cylindrical and stout body. The head length is a little less than 1/4 of the snout-vent length. Labial fold is well-developed. The number of vomerine teeth and size of the tooth patch is variable among individuals. Angle of jaw exceeds the posterior margin of eye. Gular fold is prominent and visible from above. Limbs are short and do not meet when adpressed. 11 to 13 costal grooves. The salamander has 4 fingers and 4 toes without webbing. Tips of digits are covered by keratinized epidermis but the palm and sole do not have such covering. A large tubercle is present at the base of first two fingers and first two toes. Tail length is shorter than snout-vent length. Tail is rounded at the base and flattened towards the tip. Caudal fin is present and thin at the dorsal side of the posterior part of the tail, but absent on the ventral side. The vent of the males is characterized by a transverse crescentic opening with a light-colored papilla in the middle, which is followed by a longitudinal groove posteriorly. The vent of the females is a normal longitudinal slit. Males also have a relatively short snout-vent length compared to females (Liu, 1950).
All measurements are from Luhuo County (Liu, 1950).
Male (10 specimens). Snout-vent length: 74.0–88.0 mm; Head length: 16.0–20.0 mm; Head width: 13.3–15.5 mm; tail length: 77.0–102 mm; forelimb length: 18.0–24.5 mm; hind-limb length: 20.7–27.5 mm.
Female (10 specimens). Snout-vent length: 78.0–90.0 mm; Head length: 17.8–21.5 mm; Head width: 14.0–16.5 mm; tail length: 79.0–99.0 mm; forelimb length: 18.5–21.8 mm; hind-limb length: 23.0–27.0 mm.
Batrachuperus karlschmidti is considered different from B. tibetanus both morphologically and ecologically by Zhao & Jiang (1988), although both species may coexist in the same stream. Fei et al. (2006) synonymize B. karlschmidti under the latter species. They found some B. karlschmidti from the type locality with clear spots, making it hard to distinguish the two species. Fu et al. (2001) use mitochondrial data to support the validity of B. karlschmidti, which is divergent from B. tibetanus, but they also find that the presence or absence of spots is not a good character. Fu & Zeng (2008) further support the validity of B. karlschmidti and suggest that hybridization may occur where the two species occur in sympatry.
This salamander is only found in the tributaries of the Yalong River between 29 and 32 N. latitude in southwestern China (Zhao et al., 1988).
Batrachuperus karlschmidti lives in cold montane streams at elevations of 2,000–4,500 m. The salamanders hide under large flat rocks near the margin of the stream where the current is not fast. They can also be found in rock crevices in the stream. Liu (1950) occasionally found them under logs or plant roots on the bank. Larvae and juveniles mostly stay in upper reaches of small streams or springs. The salamander’s main diet is aquatic insects and their larvae.
The breeding season likely lasts from May to early August. Recent hatchlings and egg sacs still with developing embryos have been found in July and early August (Liu, 1950). The egg sac is like a C-shaped cylindrical tube with one end attached to the underside or side of the stone near the source of the stream. The length of the egg sacs ranges from 75 to 96 mm with a diameter between 14 to 19 mm and contains seven to twelve embryos. Longitudinal creamy yellow stripes are present on the surface of the egg sacs. Hatchlings swim out through a hole at the free end of the egg sac. New hatchlings, which are light grey dorsally and yellow ventrally, range from 15 to 16 mm in total length. Metamorphosis takes place when larvae reach 8–9 cm in total length. At this stage they have indistinct marblings or spots on a dark dorsum.