Crocodile newt
Tylototriton shanjing
Order: Caudata
Family: Salamandridae
Genus: Tylototriton
This is a very striking newt. It has a robust body. The colour of the head is orange and is both flat and oval, with strongly developed cranial crests. Nostrils are close to the tip of the broad and rounded snout. It has a prominent glandular vertebral ridge. This single orange ridge runs along its back. It is lined with two parallel rows of round orange bumps or nodules, on a dark brown or maroon background. These dorso-lateral rows correspond with the ribs and have 15 or so of these row protuberances on each side of the body and anterior part of the tail. The tail and legs are entirely orange. The tail is compressed laterally, with a well-developed fin fold. The belly is dark brown with a dominant orange-yellow colouring on the chin, throat, and belly. Sexual dimorphism is not well defined. Males have somewhat thicker forearms, and have a much more swollen cloaca. The male cloaca is a small longitudinal slit; whereas, the female has a small, rounded, conical opening.
Length
Adult 13 to 17 cm
Egg 2.5 to 3 mm
Larva 13 mm
Hatchling 49 to 58 mm
Conservation Status: IUCN
Distribution
This genus, consisting of several species occurs in the mountains of western China, Myanmar, extreme northeast India, northern Thailand and Nepal. This specific species Tylototriton shanjing is known from the western Yunnan province in China, where it occurs along the Nu, Lancang and Yuan rivers.
Habitat
It inhabits cool hill forests, and secondary forests at altitudes of 1,000 to 2,500 m. It usually lives in the vicinity of slow-moving water. It can also be found in shady, moist places near rice-fields, ponds, and irrigation canals.
Diet
They are insectivorous.
Reproduction
Mating usually takes place in water a few weeks after a dormancy period from The breeding season is from May to August, when streams are in flood, and water levels rise. Mating usually takes place in water a few weeks after a dormancy period, which lasts from December to March. Courtship behaviour has been observed in captive animals. After entering the water, the pair moved cheek-to-cheek opposite each other, turning in circles. The heads formed the centre, the outer sides of their bent tails forming the edge of a circle. The male slowly fanned his bent tail in the direction of the female’s snout. During this performance, the male was observed depositing a spermatophore, after choosing a firm piece of substrate to attach it to. By continuing the rotating movement, the female is led over the cone-shaped spermatophore, which she picks up with her extended cloaca. There is a 7 - 21 day ova development period. The female then searches in the water for a suitable egg laying site. In the wild, eggs are deposited singly or in strings on aquatic plants. For egg-deposition, mainly permanent ponds are used; eggs may also be laid in clutches on land near the pond. Clutch size varies anywhere from 30 to 240. Eggs are two to three mm in diameter with a yellowish nucleus. The larvae hatch in 14 - 40 days at different stages of development and at different lengths. Light-coloured dorso-lateral lines already appear in the maturing larva; during metamorphosis the light colour becomes concentrated in a row of light spots. Metamorphosis takes place about ten weeks after hatching. At this stage they measure 45 to 58 mm. They reach sexual maturity at three to four years of age and a snout-vent length of 70 to75 mm.
Adaptation
The newt’s colouration makes it very conspicuous, so this would appear to make it vulnerable to predation. However, it is toxic; its skin contains some distasteful and potentially harmful alkaloids. Also, the skull and upper vertebrae are heavily armoured with additional layers of thick bone, which serve to deter predators. Their brilliant colouration actually enables the newt to bathe in the open during the day. Shifting reflections of light against the pebbled stream beds enables cryptic colouration i.e. colours are broken up so that they merge with the colours of the pebbles. It is considered to be mainly nocturnal. They are mostly terrestrial during the non-productive periods.
Threats to Survival
They are collected for traditional Chinese medicine and for the pet trade. Suitable habitat is reduced or degraded by infrastructure development. Natural predators include snakes and raptors. Until recently, Crocodile newts were imported into Europe and the US, from specimens caught in the wild.
