Unfortunately, this species is probably extinct (Zhao, 1998; IUCN, 2010). Incidental finds of newts, coming to the surface for fish bait held out by fishermen, date back to the 1970s and 1984. Surveys in the Kunming area, the only locality of this species, have not yielded any newts since 1979. There is even no photo of living animals.
Three factors are held responsible for the presumed extinction of the species: 1. pollution of Kunming Lake, due to growth of Kunming city and increased disposal of industrial waste and domestic sewage in the lake; 2. decrease of suitable habitat by claiming land from the lake, especially in the northern part of the lake; 3. increased presence of natural enemies such as Grass Carp and duck and possibly the introduction of Bull Frogs (Rana catesbeiana) (Zhao, 1998).
A fairly large newt (10–15 cm in total length) among the Cynops species, with a strong tendency to neoteny. Red spot at the corner of the mouth, an arched back, inconspicuous paratoid glands and bluish color of the tail in the male, similar to C. cyanurus (Zhao & Hu, 1988).
Head is a little longer than wide and high in the occipital region. The snout is short and rounded, reaching over the lower jaw. Distinct labial lobe. Eye big, situated dorso-laterally. Paratoid glands small. Gular fold more or less well developed. Stout body, a little higher than wide, no dorsolateral ridges. Tail a little shorter than head and body, compressed at the base and high, featuring a crest on dorsal and ventral sides. Tail end rather pointed. Limbs slender, with four digits on forelimbs and five on hind limbs. Digits do not have claws and are not webbed. Skin smooth, but rougher than, for instance, in C. orientalis. The male has a deep blue tail in the breeding season (Zhao, 1998). The male cloaca is rounded but not very prominent, the female cloaca is a short fold. Color is black on the back, with a distinct orange-colored vertebral ridge extending onto the tail. Occasionally orange spots on head and sides of the body. Color of ventral side red or orange with irregular dark spots, sometimes forming longitudinal rows (Chang, 1936). A noticeable orange-red spot behind the eye, at the corner of the mouth.
Many mature specimens have gill vestiges of various lengths. Individuals measured 119 mm long have complete gills with gill filaments (Fei et al., 2006). One of the type specimens has gills and contains ripe ova (Pope & Boring, 1940). A good illustration is published with the original description (Boulenger, 1905, plate 17; copied in smaller format in Wolterstorff, 1926). Photos of preserved specimens in Wolterstorff (1934, plate 1), who remarked that this newt had a fish-like appearance, adapted to an entirely aquatic life. Fei et al. (2006) report that 12 of 30 adult males and 37 of 60 adult females possess gill vestiges.
All measurements are from Fei et al. (2006).
Male (16 specimens). Total length: 106.6–127.8 mm; snout-vent length: 39.5–67.8 mm; head length: 13.3–18 mm; head width: 10–13.2 mm.
Female (29 specimens). Total length: 110.7–152 mm; snout-vent length: 63.5–80 mm; head length: 17–20.5 mm; head width: 12.5–16.4 mm.
Cynops wolterstorffi was long placed in a separate genus Hypselotriton on the basis of studies in skull morphology (Herre, 1939; Pope & Boring, 1940; Thorn, 1969), but Chang (1936) and Zhao & Hu (1988) considered the species morphologically very similar to C. cyanurus and placed it in Cynops. Local knowledge of this newt is now restricted to reports recorded from a few older fishermen, who were questioned about the occurrence of the newt in the lake (Zhao, 1998). No molecular data are available for this species; DNA extraction from museum specimens may settle its relationship to Cynops cyanurus and other Cynops species.
The species is distributed on six islands of the Ryukyu archipelago, including Amami O Shima, Yorojima and Tokunoshima of the Amami group, and Okinawajima, Sesokojima, and Tokashikijima of the Okinawa group (Hayashi et al., 1992; IUCN, 2010). There are old records about its occurrence on mount Kuanyinshan north of Taipei in Taiwan, but its presence there in recent years has not been confirmed (Zhao & Adler, 1993; Zhao, 1999). The species is presently considered extinct in Taiwan (Zhao, 1998; IUCN, 2010). On Okinawa, the species is rare and occurs in isolated patches of forest (Hayashi et al., 1992; Kato & Ota, 1993). On Tokunoshima the species occurs in and near sugar cane fields, at altitudes of 100 to 200 m, areas which until the mid sixties of the 20th century were covered by forest. Their occurrence in the remaining patches of forest on that island is doubtful (Utsunomiya et al., 1978).
The newt used to be found in shallow waters along the northern part of Kunming Lake, and also in irrigation canals, ponds and swamps. Hibernation would take place in deeper waters of the lake (Zhao, 1998). Population number was large before 1960s; more than 1 newt per 10 square meters of water surface (Fei et al., 2006).
During the breeding season in April and May, thousands of animals were reported swimming among aquatic plants in the shallow parts of the lake's shores. In 1950 the animal was still reported as abundant. Since 1979 no newts have been found (Zhao, 1998).