Species account

Description
The Blue-tailed Fire-bellied Newt in its general appearance is similar to Cynops orientalis, but differs from this 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.

Colour is dark-brown above, occasionally lighter. Colour may change to lighter olive brown or yellow during the night. Individual colour change is also clearly visible in larvae and juveniles. The vertebral ridge often is lighter than the colour 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 colour may predominate, marbled or dotted with irregular black patches. Black spots in the tail of the male. 

Total length 7 to 10 cm.

Subspecies

One subspecies, C. c. yunnanensis Yang, 1983 is recognized (according to Zhao & Adler, 1993, Yangs paper was published prior to the paper by Fei and Ye, 1983, who named the same animal C.c. chuxiongensis). 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 (males 82-96 mm, females 97-115 mm) and its uniform, dark colour 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.

Diagnosis
Vertebral ridge and red-orange spot below the eye distinguish C. cyanurus from C. orientalis. Blue tail in the male in nuptial dress.

Eggs and larvae
Eggs are laid individually, wrapped in leaves, from 1 to 24 per day up to 226 on average per season per female. For egg-deposition soft leaves of water plants are chosen at a depth of 2-6 cm below the water surface (Fei & Ye, 1988). Eggs are laid from April to early October, with a peak of the breeding season in May and June, when water temperatures are ranging from 18 to 27°C (Fei & Ye, 1990). Various differences in reproductive ecology between C. orientalis and C. cyanurus have been observed. Whereas a C. cyanurus female can produce eggs fertilized by one insemination until about two weeks after insemination by one male, a C. orientalis female can apparently store sperm longer and lay fertilized eggs until several months after one insemination (Yang & Shen, 1993). With water temperatures varying between 18 to 29°C, eggs hatch after about 17 days and metamorphosis takes place 147 days later (Fei & Ye, 1988). Yang & Shen (1993) report that metamorphosis in C. cyanurus takes longer than in C. orientalis. Larvae are dark brown to yellow and may change colour. In the final larval stages the light spots at the corners of the mouth are already visible. Total length at metamorphosis is 47 mm on average (Yang & Shen, 1993); the animals reach sexual maturity after c. two years (Fei & Ye, 1988).

Distribution
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).

Habitat
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, Conservation International and NatureServe, 2004). 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).

Behaviour
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 behaviour 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 behaviour is similar to that observed in other Cynops species (Sparreboom & Faria, 1997; Sparreboom, 1998).

Threats and conservation
The species has a relatively wide distribution; it occurs in presumably large populations and tolerates some degree of habitat modification. It is presently not considered endangered (IUCN, Conservation International, and NatureServe, 2004).

Observations in captivity
Cynops cyanurus has been captive-bred, but for unknown reasons (water quality, temperature regime?) it breeds not so easily in captivity as do other Cynops species. In captivity, as in the natural habitat, C. cyanurus starts breeding later in the season than other Cynops species and at higher temperatures, an unexpected observation for a mountain species (Sparreboom, 1998; Fleck, 2000; Miller, 2005). 

Comments

Cynops cyanurus and newts that are more or less similar to this species have appeared in the pet trade from time to time. Collecting localities are usually not known. Variation in colour, size, blue colouration of the tail, smoothness or granulation of the skin and presence of dorsal ridge, suggest that some imported specimens might belong to different but related taxa.

Cynops cyanurus male
© Max Sparreboom

 
© 2004 IUCN, Conservation International and NatureServe. (click on map to enlarge)