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| Tylototriton zaimeng Decemson, Lalremsanga, Elangbam, Vabeiryureilai, Shinde, Purkayastha, Arkhipov, Bragin & Poyarkov, 2023 |
Abstract
An integrative taxonomic analysis combining molecular and morphological lines of evidence revealed a new cryptic species in the Tylototriton verrucosus species group from Manipur, north-eastern India. The new species was previously confused with T. himalayanus and T. verrucosus. Tylototriton zaimeng sp. nov. can be distinguished from its congeners by medium body size, head massive and wide with rounded snout and very wide and protruding supratemporal bony ridges and a well-developed sagittal ridge, short limbs not overlapping when adpressed along body, wide and not segmented vertebral ridge distinct, 13–14 pairs of rib nodules, brown colouration with dull orange to yellowish-brown markings on head, vertebral ridge, rib nodules, palms, soles, vent and ventral tail ridge and by vomerine teeth organised in two distinctly curved bell-shaped series. Phylogenetic analysis of the ND2 and 16S rRNA mtDNA genes confirmed the placement of the new species to the Clade I of the subgenus Tylototriton and suggested it is a sister species of T. panwaensis and T. houi (p-distance 3.0% in ND2 gene). The range of the new species is restricted to the Khongtheng Mountain Range and is isolated from the range of T. panwaensis and T. houi in northern Myanmar and southern China, respectively. We suggest the new species to be considered as Vulnerable (VU) in the IUCN Red List.
Key Words: 16S rRNA, endemism, Khongtheng Mountain Range, mtDNA genealogy, ND2, taxonomy, Tylototriton zaimeng sp. nov.
Family Salamandridae Goldfuss, 1820
Subfamily Pleurodelinae Tschudi, 1838
Genus Tylototriton Anderson, 1871
Subgenus Tylototriton Anderson, 1871
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| Holotype of Tylototriton zaimeng sp. nov. (MZMU-3041, female) in situ. Photograph by Andrey M. Bragin and Ht. Decemson. |
Tylototriton zaimeng sp. nov.
Proposed English name: Zaimeng Lake Crocodile Newt
Diagnosis: The new species is assigned to the genus Tylototriton by having the following combination of morphological attributes: (1) the presence of dorsal granules, (2) dorsolateral bony ridges on the head, (3) the presence of dorsolateral series of rib nodules (knob-like warts); and (4) the absence of a quadrate spine and molecular data (see Fig. 2). Tylototriton zaimeng sp. nov. is distinguished from all other congeners by a combination of the following morphological attributes: (1) medium body size, adult SVL 61.4–67.5 mm in males, 61.6–68.7 mm in females; (2) tail comparatively short, subequal or slightly longer than body in both sexes, lacking lateral grooves; (3) skin roughly granulated; (4) head massive and wide, relative maximal head width comprising 24.3–27.9% of SVL; (5) snout rounded in dorsal view; (6) supratemporal bony ridges on head very wide, protruding, with rough surface, beginning at the snout; (7) sagittal ridge on head well-distinct, very wide and protruding; (8) limbs comparatively short, tips of fore-limb and hind-limb not overlapping when adpressed along body; (9) vertebral ridge distinct, wide and not segmented; (10) rib nodules distinct, 13–14 along each side of body; (11) background colouration brown; (12) head, vertebral ridge, rib nodules, palms, soles, vent and ventral tail ridge with dull orange to yellowish-brown markings; (13) vomerine teeth organised in two distinctly curved bell-shaped widening anteriorly series, with 81–113 teeth.
Etymology: The specific name “zaimeng” is given as a noun in apposition and represents a Latinised version of the Liangmei dialect word “zaimeng” literally meaning “Puzzle Lake” or “Mystery Lake”. The name is given in reference to the Zaimeng Lake – a high-elevation mountain lake in Koubru Forest Division, the famous location where the crocodile newts were for the first time recorded in Manipur. It is believed that the name of the Lake was given by the Zeliangrong ancestors of Thonglang Village who passed by the Lake, but could not find their way to their destination as they used to return to the same spot again and again and circled the Lake over and over again (Sebastian 2015).
Recommended vernacular names: We recommend the following trivial name in English: Zaimeng Lake Crocodile Newt. The vernacular name in Liangmei dialect: Tadui taku; Tangkhul: Lengva; Manipuri: Hangoi mamei panba.
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| Natural habitat of Tylototriton zaimeng sp. nov. at Zaimeng Lake, Koubru Forest Division, Kangpokpi, Manipur, India. A. Vegetation surrounding the Zaimeng Lake; B. Males of Tylototriton zaimeng sp. nov. in situ; C. Breeding habitat of Tylototriton zaimeng sp. nov., numerous individuals can be seen on the muddy bottom of the lake. Photographs by Parag Shinde and Ht. Decemson. |
Ht. Decemson, Hmar Tlawmte Lalremsanga, Premjit Singh Elangbam, Mathipi Vabeiryureilai, Parag Shinde, Jayaditya Purkayastha, Dmitriy V. Arkhipov, Andrey M. Bragin, Nikolay A. Poyarkov. 2023. A New cryptic Species of Tylototriton (Amphibia, Caudata, Salamandridae) from mysterious mountain lakes in Manipur, north-eastern India. Herpetozoa. 36: 203-224. DOI: 10.3897/herpetozoa.36.e106614
