Tylototriton pasmansi Bernardes, Le, Nguyen, Pham, Pham, Nguyen & Ziegler, 2020
Pasmans Crocodile Newt
|Species Description: Bernardes, Le, Nguyen TQ, Pham CT, Pham AV, Nguyen TT & Ziegler in Bernardes M, Le MD, Nguyen TQ, Pham CT, Pham AV, Nguyen TT, Rödder D, Bonkowski M, Ziegler T (2020) Integrative taxonomy reveals three new taxa within the Tylototriton asperrimus complex (Caudata, Salamandridae) from Vietnam. ZooKeys 935: 121–164.|
Their dorsal skin hasmore granules than their ventral skin. There are also small round protuberances arranged in transverse stripes on their stomach. The lateral skin between the limbs may be smooth. In their rib area, they have a series of distinct bumps in their skin, or nodules, that range from being more pointy or round. They have 12 - 13 trunk vertebrates. They also have a high, glandular vertebral ridge that extends from the head, but is not connected to the mid-dorsal ridge on the head, to the base of the tail. This vertebral ridge is somewhat rough, segmented, and thinner on the anterior end. When the limbs are adpressed towards each other, the digits either touch or overlap. When adpressed towards the head, the fingers either reach the eye or extend beyond. The thin tail is laterally compressed with an acuminated tip (Bernardes et al. 2020).
Tylototriton pasmansi can be distinguished by having a relatively larger interorbital distance apart when compared to T. broadoridgus, T. liuyangensis, T. panhai, and T. wenxianensis. They also have a more distinctly separated rib nodules compared to T. anhuiensis, T. broadoridgus, and Tylotriton liuyangensis, which all have a nodule-like warts that are continuous in the rib area. Their head is longer than it is wide, whereas in many other species, such as T. asperrimus, T. hainanensis, and T. ziegler, have a head that is wider than it is long. The presence of a gular fold distinguishes T. pasmansi from the absence of one in T. broadoridgus, T. vietnamensis, and T. wenxianensis. They also have generally smooth ventral skin with aligned horizontally, wrinkled tubercles as opposed to more rough skin found in T. broadoridgus, T. liuyangensis, and T. wenxianensis. Lastly, T. sparreboomi has a more orange-like color, narrower head, wider distance between the eyes, longer humerus, and more enlarged rib nodules than T. pasmansi (Bernardes et al. 2020).
In life, they are uniformly colored dark brown-gray both dorsally and ventrally. However, they also contain ventral orange-red coloration in their digits, palms, vent and along their tail. In preservative, they are a faded dark grayish green on the dorsal side. While on the ventral side, the coloration is dark brown with faded yellow in the same areas where it would be orange-red in live specimens (Bernardes et al 2020).
Variation between paratypes includes an overall stouter body build, more pronounced mid-dorsal ridges, less obvious dorsolateral ridge presence on the head and larger nodules in the rib area. Breeding pads may also be found on the anterior upper arms, which appear as pale yellow in preservative. The two subspecies can be differentiated by geography and by morphology. More specifically, in T. p. obsti has a wider head, longer and narrower snout, less visible nostrils, thinner posterior ends to the dorsolateral ridge of the head, more obvious gular fold, similarly sized, pointy rib nodules throughout their length, shorter limbs, fewer skin warts and granules - including on the lateral surfaces of the skin, and a less robust body (Bernardes et al 2020).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Viet Nam
Life History, Abundance, Activity, and Special Behaviors
They are nocturnal (Hernandez 2016). However, specimens were found between 14:00 and 16:00 h in breeding ponds (Bernardes et al. 2020).
They reproduce through internal fertilization and are oviparous, laying eggs aquatically (Hernandez 2016).
Like all newts, they change from terrestrial to aquatic morphs during their breeding season (Hernandez 2016).
Like other members in the family Salamandridae, they produce potent toxins through the granular skin (Hernandez 2016).
Trends and Threats
Relation to Humans
Possible reasons for amphibian decline
General habitat alteration and loss
Bayesian, Maximum Likelihood, and Maximum Parsimony analyses on ND2 mtDNA found that the two subspecies of T. pasmansi are members of the T. asperrimus complex, and their closest relative is T. asperrimus (Bernardes et al. 2020).
in a later study, time-calibrated Bayesian and Maximum Likelihood analyses of 12S, 16S, ND1, ND2, COI, Cytb and CR mtDNA supported the relationship between T. pasmansi and T. asperrimus, with the next most closely related species being T. sparreboomi. In the same study, time-calibrated Bayesian and Maximum Likelihood analyses of POMC, RAG1, BDNF and NCX1 nDNA placed T. pasmansi as sister to T. ziegleri, however ,the nuclear sequence phylogenies do not have strong confidence (Dufrensnes and Hernandez 2022).
The species epithet, “pasmansi”, is in honor of professor Dr. Frank Pasmans from Ghent University, whose research contributed significantly to the discovery of diseases responsible for amphibian decline (Bernardes et al. 2020).
The subspecies epithet, “obsti”, is in honor of the late professor Fritz-Jürgen Obst, who was a herpetologist and director of the Museum für Tierkunde Dresden, Germany (Bernardes et al. 2020).
Dufrensnes, C., Hernandez, A. (2022). Towards completing the crocodile newts’ puzzle with all-inclusive phylogeographic resources. Zoological Journal of the Linnean Society 197(3): 620–640. [link]
Hernandez, A. (2016). Crocodile Newts: The Primitive Salamandridae of Asia (Genera Echinotriton and Tylototriton. Chimaira edition, Frankfurt. [link]
IUCN SSC Amphibian Specialist Group. (2021). Tylototriton pasmansi. The IUCN Red List of Threatened Species 2021: e.T179063834A185452241. https://dx.doi.org/10.2305/IUCN.UK.2021-3.RLTS.T179063834A185452241.en. Accessed on 23 September 2022.
Sodhi, N.S., Posa, M.R.C., Lee, T.M., Bickford, D., Koh, L.P. Brook, B.W. (2010). The state and conservation of Southeast Asian biodiversity. Biodiversity and Conservation 19: 317-328. [link]
Originally submitted by: Kevin Dang (2023-05-18)
Description by: Kevin Dang (updated 2023-05-18)
Distribution by: Kevin Dang (updated 2023-05-18)
Life history by: Kevin Dang (updated 2023-05-18)
Trends and threats by: Kevin Dang (updated 2023-05-18)
Relation to humans by: Kevin Dang (updated 2023-05-18)
Comments by: Kevin Dang, Ann T. Chang (updated 2023-05-18)
Edited by: Ann T. Chang (2023-05-23)
Species Account Citation: AmphibiaWeb 2023 Tylototriton pasmansi: Pasmans Crocodile Newt <https://amphibiaweb.org/species/9191> University of California, Berkeley, CA, USA. Accessed May 28, 2023.
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Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 28 May 2023.
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