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| Tylototriton umphangensis Pomchote, Peerachidacho, Hernandez, Sapewisut, Khonsue, Thammachoti & Nishikawa, 2021 กะท่างน้ำอุ้มผาง | Umphang Crocodile Newt || DOI: 10.3897/zookeys.1072.75320 |
Abstract
We describe a new species of the newt genus Tylototriton from Umphang Wildlife Sanctuary, Tak Province, western Thailand based on molecular and morphological evidence and named here as Tylototriton umphangensis sp. nov. The new species is assigned to the subgenus Tylototriton and differs from other species in having dark-brown to blackish-brown body and limbs, truncate snout, prominent antero-medial ends of the expansion of the dentary bones, laterally protruding quadrate regions, indistinct and small rib nodules, a well-segmented vertebral ridge, and rough dorsolateral bony ridges, which are steeper anterior, and curved medially at the posterior ends. The molecular data show that Tylototriton umphangensis sp. nov. differs from T. uyenoi sensu stricto by a 5% genetic sequence divergence of the mitochondrial NADH dehydrogenase subunit 2 region gene. The new species and T. uyenoi are both endemic to Thailand, distributed along the Northwest Thai (Dawna) Uplands of Indochina. To clarify the species boundary between Tylototriton umphangensis sp. nov. and T. uyenoi, additional field research is needed in adjacent areas. Tylototriton umphangensis sp. nov. is restricted to evergreen hill forests in Umphang Wildlife Sanctuary. We suggest that the new species should be classified as Endangered (EN) in the IUCN Red List.
Keywords: conservation, crocodile newt, cryptic species, South-east Asia, taxonomy
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| Male Tylototriton umphangensis sp. nov. |
Tylototriton umphangensis sp. nov.
Thai name: กะท่างน้ำอุ้มผาง - Ka Tang Nam Umphang
English name: Umphang Crocodile Newt
T. uyenoi: (referring to the population from Umphang, Tak Province): Hernandez et al. 2019, page 18.
Diagnosis: The new species is placed in the genus Tylototriton by having a combination of dorsal granules present, dorsolateral bony ridges on head present, knob-like warts (rib nodules) on dorsolateral body present, and quadrate spine absent. Tylototriton umphangensis sp. nov. differs from its congeners by having the following morphological characters: medium-sized, adult SVL 65.6–75.3 mm in males; skin rough with fine granules; snout truncate; quadrate regions laterally protruding; antero-medial ends of dentaries distinctly expanded; dorsolateral bony ridges on head prominent, steep, rough, narrow, and posterior ends curved medially; parotoids distinct, oriented rather parallel to the body axis and posterior part curved upwards in the lateral view; vertebral ridge distinct and segmented; rib nodules 14–15, small, and indistinct; limbs long and thin; tips of forelimbs and hindlimbs overlapping when adpressed along the body; tail thin.
Etymology: The specific epithet umphangensis refers to Umphang Wildlife Sanctuary, the type locality of the new species.
Distribution: Umphang Wildlife Sanctuary, Tak Province, western Thailand (Fig. 1). The Umphang Wildlife Sanctuary is located along the Dawna Range, which is a mountain range in eastern Myanmar and northwestern Thailand. Thus, this species is expected to also occur in Myanmar and elsewhere in western Thailand.
Natural history: All specimens were found during the afternoon at around 14:30 h hidden under leaf litter and between stems of arrowroot plants (family Marantaceae) in a small ephemeral pond (Fig. 7) during the rainy season, which is the breeding season of Tylototriton species. The pond had clear water and the bottom was covered with dense leaf litter. The surrounding area was composed of hill evergreen forest. The pond size was approximately 520 cm long, 270 cm wide, and 17 cm in maximum depth. The water temperature was 23.1 °C. The water quality parameters were: pH 6.4; dissolved oxygen 4.13 mg/L; conductivity 23 µS/cm; total dissolved solid 15 mg/L; and turbidity 7.6 NTU. No fish were observed.
Porrawee Pomchote, Parada Peerachidacho, Axel Hernandez, Pitak Sapewisut, Wichase Khonsue, Panupong Thammachoti and Kanto Nishikawa. 2021. A New Species of the Genus Tylototriton (Urodela, Salamandridae) from western Thailand. ZooKeys. 1072: 83-105. DOI: 10.3897/zookeys.1072.75320
Axel Hernandez, Daniel Escoriza, Porrawee Pomchote and Mian Hou. 2019. New localities for Tylototriton uyenoi, T. panhai and T. anguliceps in Thailand with remarks on the southernmost distribution of the genus. The Herpetological Bulletin. 147: 15–18. DOI: 10.33256/hb147.1518