Species Description: Le DT, Nguyen TT, Nishikawa K, Nguyen SLH, Pham AV, Matsui M, Bernardes M, Nguyen TQ. 2015 A new species of Tylototriton Anderson, 1871 (Amphibia: Salamandridae) from Northern Indochina. Current Herpetology 34: 38-50.
© 2019 Axel Hernandez (1 of 8)
Like the adults, larvae also have a trapezoidal head that is depressed and sloping in profile. The larval snout is short and somewhat truncate with a distinct labial fold at the posterior half of the upper jaw. The caudal fin is higher than the head, and the dorsal fin higher than the ventral fin. The dorsal fin emerges intermediately between the insertion of the forelimb and middle of middle of the trunk. The ventral fin has a pointed tail tip and originates from the vent (Le et al. 2015).
Adults have bright orange heads, trunks, limbs, and tail markings that differentiate T. anguliceps from T. daweishanensis, T. taliangensis, T. verrucosus, and members of the subgenus Yaotriton, except for T. panhai. Its orange head and limbs also distinguish T. anguliceps from T. panhai, while the isolated markings on its rib nodules distinguish it from T. kweichowensis, and T. pseudoverrucosus. In addition, T. shanjing, T. shanorum, and T. uyenoi lack the prominent middorsal bony ridge as well as the steep, narrow dorsolateral bony ridges on its head, both of which are characteristic of T. anguliceps. The black ground coloration of T. anguliceps’ body differentiates it from T. pulcherrima, while the orange anterior half of its head differentiates it from T. yangi. Skull morphology is also useful for distinguishing Tylototriton anguliceps from other closely related species. The skull of T. anguliceps features a well-defined crest as well as skeletal connection between the maxillary and pterygoid. Although the maxillary and pterygoid skeletal connection is not characteristic other Tylototritoni, it is also found in Echinotriton, the sister genus of Tylototriton (Le et al. 2015).
Tylototriton anguliceps adults have a dark brown to black dorsal base color. The coloration of the venter is somewhat lighter than that of the dorsum. Bright to dark orange coloration covers the entire head, parotoids, vertebral ridge, rib nodules, limbs, and sections of the ventral trunk, pectoral and public regions, vent, and entire tail. In preservative, the dorsal ground coloration usually fades to light brown, while the orange markings fade to a light cream color (Le et al. 2015).
Dorsally, larvae are light yellowish-brown with a whitish, transparent venter and black spots finely scattered on the dorsal head. These spots form irregular dark splotches on the dorsal trunk, lateral body, and tail fin edge. Larval fingers and toes are yellow. In preservative, dorsal coloration fades to a light cream color (Le et al. 2015).
Although males are smaller than females in general, their limbs are more robust. In males, tails and vent slit lengths are also relatively longer than in females. Specimens often varied in the amount of segmentation between vertebral ridges, and many were more distinctly segmented than the holotype. The length of the vomerine tooth row also varied between specimens. Lastly, markings varied in brightness (Le et al. 2015).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Lao People's Democratic Republic, Thailand, Viet Nam
Life History, Abundance, Activity, and Special Behaviors
Adults are terrestrial, and gravitate toward rotten logs and leaf litter near breeding bodies of water. After rainfall, they often reside on the forest floor (Le et al. 2015).
Mature eggs range in size from 2.0 to 2.7 mm. In general, the egg is a dark cream color and the animal pole is dark brown. Clutch size is unknown (Le et al. 2015).
Trends and Threats
Tylototriton anguliceps is part of the subgenus, Tylototriton, based on a molecular phylogeny using Bayesian analyses of 988 base pair sequences of the partial ND2 mt DNA sequence. In addition, mitochondrial DNA, nuclear DNA, and morphological characteristics indicate that T. anguliceps forms a sister group with T. uyenoi. Nuclear genes sequenced includes proopiomelanocortin (POMC) and Rag1 (recombination activating protein 1; Le et al. 2015, Nishikawa et al. 2013).
In Latin, “angulus” means angular while “ceps” means head, and together they refer to the steep, narrow bony ridges on Tylototriton anguliceps’ head (Le et al. 2015).
Tylototrion anguliceps shares much of its range with T. uyenoi (Le et al. 2015).
Tylototriton anguliceps likely occurs in regions bordering northwestern Vietnam and northern Thailand, such as southern China, western Myanmar, and northern Laos. Tylototrion anguliceps may occur sympatrically with one species of the T. verrucosus-shanjing complex due to overlapping ranges, though this co-occurrence is not yet documented (Le et al. 2015).
Le, D.T., Nguyen, T.T., Nishikawa, K., Nguyen, S.L.H., Pham, A.V., Matsui, M., Bernardes, M., Nguyen, T.Q. (2015). ''A new species of Tylototriton Anderson, 1871 (Amphibia: Salamandridae) from northern Indochina.'' Current Herpetology, 34(1), 38-50. [link]
Nishikawa, K., Khonsue, W., Pomchote, P., Matsui, M. (2013). ''Two new species of Tylototriton from Thailand (Amphibia: Urodela: Salamandridae).'' Zootaxa, 3737(3), 261 - 279. [link]
Ohler, A., Shunqing, L., Datong, Y. (2004). Tylototriton shanjing. The IUCN Red List of Threatened Species 2004: e.T59485A11934078. http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T59485A11934078.en. Downloaded on 26 April 2016.
Originally submitted by: Nicole Duong (first posted 2016-04-25)
Edited by: Ann T. Chang (2020-10-29)
Species Account Citation: AmphibiaWeb 2020 Tylototriton anguliceps: Angular-headed newt <https://amphibiaweb.org/species/8316> University of California, Berkeley, CA, USA. Accessed Oct 27, 2021.
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Citation: AmphibiaWeb. 2021. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 27 Oct 2021.
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