AMPHIBIAWEB
Tylototriton verrucosus
Himalayan Newt, Red Knobby Newt
Subgenus: Tylototriton
family: Salamandridae
subfamily: Pleurodelinae
 
Species Description: Nussbaum, R. A., Brodie, Jr., E. D., Yang, D. 1995. A Taxonomic Review of Tylototriton verrucosus Anderson (Amphibia: Caudata: Salamandridae). Herpetologica, 51(3): pp. 257-268.

© 2004 Jessica Miller (1 of 54)

AmphibiaChina 中国两栖类.

Conservation Status (definitions)
IUCN (Red List) Status Least Concern (LC)
CITES No CITES Listing
Other International Status Lower Risk (near threatened)
National Status Lower Risk (near threatened)
Regional Status None

 

View distribution map using BerkeleyMapper.

   

From the Encyclopedia of Life account:

Habitat

The terrestrial habitat is largely moist forest, or sites where mountain forests previously existed, such as rice fields, tea gardens, meadows covering the shores of mountain ponds and lakes, forest edges, etc.. The animals generally remain close to water (AmphibiaWeb, 2010). Aquatic habitats include various freshwaters including permanent pools and forest streams, natural and artificial ponds, rain puddles and swamps (Seglie, 2002). Breeding occurs in the shallow areas of these water bodies. In the southern part of its range it is generally an upland species occurring at elevations between 1,000 - 3,000 m., in the northern part of its range T. verrucosus is reported from low hills below 1,000 m. (IUCN, 2010)

Although it is not usually common, population density may locally be very high, from 71 to 101 per 100 square meters breeding pond (Seglie, 2002). Food consists of aquatic and terrestrial insects, bivalves, cannibalized eggs of T. verrucosus and vegetal material (Anders et al., 1998). Young larvae feed on mosquito larvae, microcrustaceans, chironomids and various other benthic prey; larvae of later stages prey on aquatic insects and small crabs; after metamorphosis food consists of small bivalves and terrestrial food such as Collembola, larval Lepidoptera, larval Diptera and isopods. The adult diet consists of Lumbricidae, larval Diptera, Coleoptera, Lepidoptera, and Odonata, adult dytiscid beetles, larvae of frogs and cannibalized eggs (Dasgupta, 1996).


Authors: Wu, Yunke; Sparreboom, Max
License: http://creativecommons.org/licenses/by-nc/3.0/

Distribution

From India (West Bengal and Sikkim and smaller, isolated populations in Manipur and Arunachal Pradesh) and eastern Nepal through the Kachin and Shan Hills of Myanmar to southwestern Yunnan (Longchuan county and its vicinity), China and scattered mountains in northern Thailand. It has recently been recorded from Lai Chau Province in Vietnam. The boundary between this species and Tylototriton shanjing is not clear (IUCN, 2010; Yang & Rao, 2008).


Authors: Wu, Yunke; Sparreboom, Max
License: http://creativecommons.org/licenses/by-nc/3.0/

Morphology

A large and robust salamander. Head flat and oval, with strongly developed cranial crests and cranial boss. Nostrils close to the tip of the broad and rounded snout. Eyes of moderate size with large, granular upper eyelid. Prominent glandular vertebral ridge. Dorso-lateral row of 15 nodules on each side of body and anterior part of the tail. Fingers and toes not webbed. Skin of body and tail granular. Paratoids large and distinct, slightly concave. Gular fold present. Tail compressed laterally, with well-developed fin fold, a little shorter than snout-vent length. Color uniformly dark brown on dorsum, sides and venter. Tail and soles of hands and feet lighter brown than body. Underside of tail lighter, sometimes yellow or orange. This description applies to animals from Nepal (Anders et al., 1998) and largely conforms to the original description (Anderson, 1871), based on specimens from western Yunnan and the description of specimens from Taunggyi in Burma (Thant-Shima et al., 1979) and the Darjeeling area in India (Kuzmin et al., 1994). There is regional variation in the prominence of the vertebral and dorsolateral ridges. There is also variation in contrast between the cranial ridges, paratoids, and dorsolateral nodules, colored in different shades of light brown to yellow, and the dorsum which varies between dark chocolate-brown to black. Specimens from Phu Luang, Thailand, for instance, show a strong contrast between the black dorsum and dorsolateral and dorsal ridges (Wongratana, 1984; Chan-Ard et al., 1999), resembling the color pattern of T. shanjing (Nussbaum et al., 1995). The light-brown to black contrast is more pronounced in terrestrial than in aquatic salamanders. Sexual dimorphism is poorly developed. Females are longer and heavier than males; they have larger heads and longer limbs, but smaller cloacas and lower tails (Seglie, 2002) The cloaca of the male is characterized by a small longitudinal slit, that of the female by a small rounded opening. In the breeding season the female cloaca is more conical in shape than that of the male (Anders et al., 1998).


Authors: Wu, Yunke; Sparreboom, Max
License: http://creativecommons.org/licenses/by-nc/3.0/

Size

All measurements are from Nussbaum et al. (1995).

Male (neotype). Snout-vent length: 74.8 mm; tail length: 74.1 mm; head length: 16.8 mm; head width: 15.7 mm; forelimb length: 24 mm; hind-limb length: 24 mm.

Average total length of animals from Darjeeling is 17.5 cm for females and 15.4 cm for males (Seglie, 2002).


Authors: Wu, Yunke; Sparreboom, Max
License: http://creativecommons.org/licenses/by-nc/3.0/

Diagnostic Description

Dark-brown salamander with vertebral ridge and dorsolateral rows of warts. Strongly developed cranial crests and cranial boss. Skull surface is covered with prominent dorso-lateral bony crests and a median crest on the parietalia. Differs from Tylototriton shanjing in lacking the bright orange head and dorsolateral nodules and having no ossified structures on the median part of the frontals (Haller-Probst, 1998).


Authors: Wu, Yunke; Sparreboom, Max
License: http://creativecommons.org/licenses/by-nc/3.0/

Reproduction

Reproduction starts soon after the newt emerges from hibernation. In a large part of its range, reproduction coincides with the start of the monsoon season (late March to early April). Males enter the breeding pond first and may stay longer than females, accounting for seasonal fluctuations in sex ratio. Spawning occurs between March and May, and may continue throughout the rainy season (as late as September). Females leave the water soon after laying eggs (Seglie, 2002). In October, most adults leave the water bodies (AmphibiaWeb, 2010).

Courtship behavior was first observed in specimens from upper Burma (Boulenger, 1920). Boulenger observed that the male clasped the female from below, with his forelimbs hooked over the forelimbs of the female, similar to Pleurodeles waltl. Several fragmentary descriptions are given in the literature. The following account is based on observation of one couple of T. verrucosus from Burma (Myanmar), placed in an aquarium by Thant-Shima et al. (1979). The aquarium was filled with fresh water of 24–25 °C. After one to two days the male grasped the female from below, hooking his fore limbs around her shoulders as described by Thorn (1969) and swam around with her in the tank. After six to twelve hours, the pair moved to the bottom and started making a rotating movement around each other, their heads turned towards each other. This could take a few hours or the whole night. During this movement, the cloaca of both sexes was wide open. The male deposited several spermatophores onto pebbles by rubbing over them with his cloaca. The spermatophores were of conical shape and transparent, apart from the white part on the top, from which microscopically small sperm was seen diffusing in the water. Apparently the female caught the sperms into her cloaca by rubbing her cloaca over the sperm during the rotating movement. Several hours later, the female started to lay eggs.

Eggs are laid onto submerged vegetation and on the bottom of a pond, rarely outside water. Records of clutch size vary between 26–60 (AmphibiaWeb, 2010) to 30–400 eggs (Thant-Shima et al., 1979). When the gelatinous envelope is fully distended, the egg measures between 6 and 10 mm in diameter (Smith, 1924), the embryo 2 mm (Sparreboom, 1999). Larvae hatch after 7 to 20 days, c. 11 mm long. The fully grown larva has a tail as long as, or a little shorter than, head and body, its tip obtusely pointed. Upper crest of tail not reaching the head. Skin finely or coarsely granular. The prominent ridges on the sides of the head, characteristic of the adult, are just apparent. Knob-like projections on flanks visible as elongated vertical folds of skin. Color olive-brownish, thickly speckled with darker markings. Metamorphosis occurs between summer and autumn at a total length between 37 and 75 mm (Smith, 1924; Schleich & Kästle, 2002). Larvae of late clutches are known to overwinter. The age of sexual maturation is around 3–5 years, and maximum longevity on record is 11 years (Kuzmin et al., 1994; AmphibiaWeb, 2010).


Authors: Wu, Yunke; Sparreboom, Max
License: http://creativecommons.org/licenses/by-nc/3.0/

Evolution

When Anderson (1871) published the description of Tylototriton verrucosus, he described the species as a uniformly blackish brown newt. He did not designate a type series and only later presented a specimen to British Museum of Natural History which is registered as a syntype. The coloration of this specimen, however, does not match the original description because it has a vivid orange cranial crest, paratoid glands, vertebral crest, dorsolateral warts, four limbs and tail. Nussbaum et al. (1995) recognized the orange color morph as a new species, T. shanjing, based on coloration and results from morphometric analyses. A neotype from Longchuan, Yunan was designated for T. verrucosus, which now represent the brown color morph.

Zhang et al. (2007) suggested that the two color morphs should belong to the same species based on mitochondrial phylogeny. But only a single specimen of T. verrucosus was included in their study. Using T. verrucosus from localities different from Zhang et al. (2007), Stuart et al. (2010) found relatively large mitochondrial genetic divergence between T. verrucosus and T. shanjing, supporting the validity of both species.


Authors: Wu, Yunke; Sparreboom, Max
License: http://creativecommons.org/licenses/by-nc/3.0/

Genetics

Karyotype:

2n=24, 1M, 2M, 3M, 4M, 5M, 6SM, 7SM, 8M, 9M, 10M, 11M, 12ST, Seto et al. (1982). M: metacentric; SM: submetacentric; T: telocentric; ST: subtelocentric

Mitochondrial and nuclear sequence data are available in Zhang et al. (2007) and Stuart et al. (2010).


Authors: Wu, Yunke; Sparreboom, Max
License: http://creativecommons.org/licenses/by-nc/3.0/

Conservation

Habitat loss from infrastructure development and regular human-induced forest fires (in Southeast Asia) are a threat to this species. Water pollution from agrochemicals and domestic detergents, and the extraction of water for irrigation are also degrading its habitat. The species is considered a bad omen and thus killed in Myanmar in certain areas (Gyi, 1969). It is used as bait for fishing in Myanmar and is in demand in the domestic and international pet trade. It is also harvested for use as a traditional medicine in India (IUCN, 2010). In the Darjeeling District the principal problem is the high rate of habitat loss due to human activities, draining of ponds, and introduction of fish (Seglie, 2002; Seglie et al., 2003). The species or its habitat is protected by legislation in Nepal, India, China and Thailand. Initiatives for conservation have been taken in India and Thailand (Humphrey & Bain, 1990; Seglie, 2002).


Authors: Wu, Yunke; Sparreboom, Max
License: http://creativecommons.org/licenses/by-nc/3.0/