Cynops chenggongensis Kou and Xing, 1983
This species is only known from its type locality and has not been found in recent years. Conservation data are deficient (IUCN, 2010).
A distinct yellow or orange spot below eye. Skin is smooth in life. Vertebral ridge inconspicuous. Bright spots form two dorsolateral lines in most specimens. Conspicuous black spots present on the tail of females.
Cynops chenggongensis resembles C. cyanurus in external morphology but differs from it by a smoother skin and less conspicuous vertebral ridge (Kou & Xing, 1983). Skin is rather granulated in C. cyanurus, and its vertebral ridge is very conspicuous. The original description claimed that the two species can be further distinguished by the presence of conspicuous black spots on the tail of female C. chenggongensis (Kou & Xing, 1983). But black caudal spots are also observed in female C. cyanurus (Fei et al., 2006).
Summarized from Kou & Xing (1983). A relatively small newt. Head slightly flattened. Snout is rounded and slightly protrudes beyond mandibles. Nostrils situated at snout tip. Labial fold very conspicuous, covering 2/3 of mandibles. Gular fold present. Paratoid gland and vertebral ridge inconspicuous. When limbs are adpressed, digits do not or only slightly meet. Tail length shorter than snout-vent length. Tail is laterally compressed. Skin very smooth in life but becomes slightly granulated after preservation. Male cloaca is swollen with papillae on inner wall. A distinct yellow or orange spot below eye. Dorsal coloration is greenish yellow with dark spots or blotches. In most specimens, orange spots (1–10 spots or even more on each side) form two dorsolateral lines. Ventral coloration is bright orange with irregular black blotches. Conspicuous black spots present on the tail of females. Tail of males develops a blue sheen during breeding season.
All measurements are from Kou & Xing (1983).
Male (78 specimens). Total length: 78.5–95.5 mm; tail length: 32–41.2 mm; head length: 9–11.2 mm; head width: 8.8–10.5 mm.
Female (39 specimens). Total length: 90–106.2 mm; tail length: 36–46.6 mm; head length: 10–12 mm; head width: 9.2–11.5 mm.
Based on the presence of a distinct orange spot below the eye, Cynops chenggongensis is most probably closely related to C. cyanurus and C. wolterstorffi. All three species occur on the Yunnan-Guizhou Plateau, the eastern extension of the Tibetan Plateau. However, no molecular data are available for this species, so its relationship to other Cynops remains to be settled.
Only known from the type locality of Shuitang, Chenggong County, Yunnan, China, at 1,940 m altitude.
This species is found in water in rice fields and ditches near rice fields at around 2,000 m altitude. Hibernation starts in October and takes place underground (less than 10 cm deep).
Breeding season probably starts late March to early April. One female lays 200–300 eggs each year. The diameter of the egg capsule is 2.8–3.6 mm and the diameter of the embryo is 1.7–1.8 mm. Dissection revealed that females shorter than 82.5 mm in total length are not sexually mature (Kou & Xing, 1983).