Cynops cyanurus Liu, Hu and Yang, 1962
The species has a relatively wide distribution; it occurs in presumably large populations and tolerates some degree of habitat modification. Cynops cyanurus also appears in the pet trade. It is listed as of least concern by IUCN (2010).
Presence of conspicuous vertebral ridge and red-orange spot below the eye. Blue tail in the male in nuptial dress. Skin rather granulated.
Karyotype:
Cynops cyanurus cyanurus: 2n=24, 1M, 2M, 3M, 4M, 5M, 6M, 7SM, 8M, 9M, 10SM, 11SM, 12SM, from Gu & Tian (2000).
Cynops cyanurus yunnanensis: 2n=24, 1M, 2M, 3M, 4M, 5M, 6M, 7M, 8SM, 9SM, 10M, 11M, 12M, from Yang (1992).
M: metacentric; SM: submetacentric; T: telocentric; ST: subtelocentric; m: micro-chromosome
The mitochondrial genome has been sequenced by Zhang et al. (2008). Mitochondrial data of both subspecies are available in Wu et al. (2010).
Cynops cyanurus in its general appearance is similar to C. orientalis, but differs from the latter species in the following aspects: Paratoid glands inconspicuous, noticeable vertebral ridge, orange-red spot at the corners of the mouth, skin rather granulated; occipital V shaped ridge connected to vertebral ridge, vertebral ridge and limbs brownish; distinct inner and outer metacarpal and metatarsal tubercles, of which the outer ones are conical (Liu et al., 1962; Zhao & Hu, 1988). Tail is shorter than snout-vent length and tapering gradually towards the tip; tail-tip rounded or ending in a blunt tip. Male smaller than female. In the reproductive season the male has a distinct blue sheen along the tail, which sometimes extends over the flanks. The male cloaca is swollen. Color is dark-brown above, occasionally lighter. Color may change to lighter olive brown or yellow during the night. Individual color change is also clearly visible in larvae and juveniles. The vertebral ridge often is lighter than the color of the back. The vent is covered with an irregular pattern of red or orange spots on a dark-blue to black background; the orange color may predominate, marbled or dotted with irregular black patches. Black spots in the tail of the male.
Besides the nominate form (Cynops cyanurus cyanurus), another subspecies C. c. yunnanensis Yang, 1983 is recognized (according to Zhao & Adler, 1993, Yang’s paper was published prior to the paper by Fei & Ye, 1983, who named the same animal C. c. chuxiongensis; but according to Fei et al., 2006, the paper by Fei & Ye, 1983 was received by the journal prior to the paper by Yang, 1983). This form occurs in Chuxiong and Jingdong counties in northeastern Yunnan at altitudes between 2,400 and 2,600 m. It differs from the nominate form in its larger size (total length: males 82–96 mm, females 97–115 mm) and its uniform, dark color of the upper parts of limbs, body and muscular part of the tail. Anterior half of the cloaca is orange-red, posterior part grayish black, inferior caudal fin fold orange-red, bordered with a dark wavy line (Fei & Ye, 1983). The ecological data published by Fei and Ye (1988, 1990), referred to below, apply to this subspecies.
All measurements are from Fei et al. (2006).
Cynops cyanurus cyanurus:
Male (16 specimens). Total length: 72.5–85 mm; snout-vent length: 40.5–48.1 mm; head length: 8.2–10.5 mm; head width: 8.4–10 mm.
Female (13 specimens). Total length: 74.5–99.5 mm; snout-vent length: 38.2–57.2 mm; head length: 9.3–13.2 mm; head width: 8.5–11.3 mm.
Cynops cyanurus yunnanensis:
Male (10 specimens). Total length: 82.1–69.4 mm; snout-vent length: 46–54.4 mm; head length: 10.5–12 mm; head width: 9.6–11.3 mm; forelimb length: 13.4–17.8 mm; hind-limb length: 14.2–18 mm.
Female (10 specimens). Total length: 97.1–114.7 mm; snout-vent length: 54–63.3 mm; head length: 11.8–13.9 mm; head width: 10.7–13.6 mm; forelimb length: 15.2–17.8 mm; hind-limb length: 16.4–18.8 mm.
Based on the presence of a distinct orange spot below eye, Cynops cyanurus is very likely closely related to C. chenggongensis and C. wolterstorffi. All three species occur on the Yunnan-Guizhou Plateau, the eastern extension of the Tibetan Plateau. They form one of the three species groups in Cynops (the other two are the C. orientalis species group and the Japanese species group, Zhao & Hu, 1988). Wu et al (2010) sequenced C. cyanurus cyanurus and C. c. yunnanensis and found a relatively large genetic divergence.
The species is known from Guizhou and Yunnan from altitudes between 1,790 and 2,400 m. It is common on the Yunnan plateau (Yang, 1991; Fei et al., 1999).
Ponds in mixed forest and paddy fields. Breeding takes place in shallow waters such as irrigated paddy fields, ponds in the forest and also in artificial ponds close to Kunming (IUCN, 2010). After the reproductive season, in October, the animals go on land. They never move far away from the water and live in secondary coniferous and broadleaf forest (Fei & Ye, 1990).
The newts hibernate in damp caves or stone crevices near the reproductive waters from October to April. Reproduction takes place in calm water at water temperatures of 18 to 27°C, especially in the shallow parts at a depth of 10 to 20 cm that warm up easily. Peak of breeding activity is in May and June (Fei & Ye, 1990).
The sexual behavior was first studied in the laboratory and published by Fei and Ye (1988): The male follows the female and tries to block her path. When the female stops moving, the male will touch her with his snout and occasionally bite her. He fans his tail in front of her snout, fanning bouts lasting 2 to 5 seconds with 3 seconds intervals. This he may continue to do for about 20 minutes. Once responsive, a female moves forward and touches the male with her snout or bites him 5 to 10 times. The male turns round 180 degrees and starts creeping ahead of her, his tail making snake-like movements. The female follows him and continuously touches or nibbles at his undulating tail. After creeping 10 to 20 cm, the male raises his tail and deposits a spermatophore. The spermcap is 3.5 to 6.5 mm long and 0.5 to 0.8 mm in diameter. The spermcap attaches to the female cloaca and is absorbed in 25 to 40 minutes. If the sperm is picked up, the female generally loses interest and stops being responsive. If the spermcap is missed, the female keeps creeping and the male may deposit one or two more spermatophores. This behavior is similar to that observed in other Cynops species (Sparreboom & Faria, 1997; Sparreboom, 1998).