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| Microhyla tetrix Poyarkov, Pawangkhanant, Gorin, Juthong & Suwannapoom, 2020 |
ABSTRACT
An integrative taxonomic analysis recovered the new miniaturised species Microhyla tetrix sp. nov. of the M. superciliaris group as the sister species to M. superciliaris. The new species inhabits low-elevation to mid-elevation evergreen tropical forests of Ratchaburi, Phetchaburi, Prachuap Khiri Khan, Chumphon, Surat Thani and Krabi provinces of south-western Thailand. Additionally, our analysis supports the occurrence of M. superciliaris in Songkhla Province of southern Thailand. Our results underscore the important role of the Isthmus of Kra – a well-known biogeographic region of cladogenic turnover – in differentiation of the M. superciliaris species group. The description of Microhyla tetrix sp. nov. and the record of M. superciliaris brings the total number of species of Microhyla in Thailand to nine. Our work underlines the physiographic complexity of the Thai–Malay Peninsula and the need for intensified field surveys and integrative taxonomic studies for further exploration of its poorly understood herpetofauna.
Keywords: Thai–Malay Peninsula, Indochina, Kangar–Pattani line, Isthmus of Kra, Microhyla tetrix sp. nov, Microhyla superciliaris , biodiversity, taxonomy, mtDNA
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| Distribution of Microhyla superciliaris species group in Thai-Malay Peninsula. A star denotes a type locality; a dot in the centre of an icon denotes populations included in phylogenetic analyses. Localities: Microhyla tetrix sp. nov.: THAILAND: (1) Suan Phueng Dist., Ratchaburi Prov. (this study); (2) Khao Kra Puk Mt., Phetchaburi Prov. (this study); (3) Kui Buri NP, Prachuap Khiri Khan Prov. (Taksintum et al. 2009, 2010); (4) 'Klong Bang Lai, Patiyu', now Pathio Dist., Chumphon Prov. (Smith 1916); (5) Wat Tham Sanook, Chumphon Prov. (this study); (6) Khao Sok Dist., Surat Thani Prov. (this study); (7) Phanom Dist., Surat Thani Prov. (this study); (8) Klong Sok Dist., Surat Thani Prov. (this study, type locality); (9) Ao Nang, Krabi Prov. (this study); Microhyla superciliaris: THAILAND: (10) Saba Yoi, Songkhla Prov. (this study); MALAYSIA: (11) Tasik Pedu Lake; Kedah (Manthey and Denzer 2014; Manthey et al. 2016); (12) Sedim, Kedah (Manthey et al. 2016); (13) Lenggong, Perak (Manthey et al. 2016); (14) Lata Belantan, Terengganu (Manthey et al. 2016); (15) Sekayu, Terengganu (Manthey et al. 2016); (16) Kuala Tahan, Pahang (Manthey et al. 2016); (17) Temerloh, Pahang (Matsui et al. 2011); (18) Batu Caves, Kuala Lumpur (Parker 1928); (19) Forest Research Institute of Malaysia office, Selangor (Manthey et al. 2016); (20) Kenaboi, Negeri Sembilan (Matsui et al. 2011); (21) Gunung Belumut, Johor (Manthey et al. 2016); (22) Gunung Panti, Johor (Manthey et al. 2016). Colours of localities correspond to those used in Figure 2. Photos by Parinya Pawangkhanant. Dashed lines indicate the Isthmus of Kra and the Kangar-Pattani line biogeographic borders (given following Baltzer et al. 2008). |
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| Bayesian inference tree of Microhyla derived from the analysis of 2428 bp of alignment including 12S rRNA, tRNA Val and 16S rRNA gene fragments. For voucher specimen information and GenBank accession numbers see Supplementary Table S2. Red and green colour denotes Microhyla tetrix sp. nov. and Microhyla superciliaris, respectively (see Figure 1); grey denotes M. superciliaris group members. Microhyla species occurring on the Thai-Malay Peninsula are underlined. Numbers at tree nodes correspond to posterior probability and bootstrap support values, respectively. Outgroup taxa not shown. Photos by Parinya Pawangkhanant. |
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| Dorsolateral view of holotype of Microhyla tetrix sp. nov. in situ (AUP 00603, a female from Klong Sok Dist., Surat Thani Prov.). Photo by Parinya Pawangkhanant. |
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| Variation in colouration of Microhyla tetrix sp. nov. (in situ). (a) Adult female from Ao Nang Dist., Krabi Prov. (not collected); (b) paratype AUP 00601, female from Klong Sok Dist., Surat Thani Prov.; (c) paratype AUP 00605, male from Klong Sok Dist., Surat Thani Prov.; (d) adult female from Wat Tham Sanook, Chumphon Prov. (not collected); (e) paratype ZMMU A6033, female from Klong Sok Dist., Surat Thani Prov.; (f) paratype ZMMU A6035, male from Khao Kra Puk Mt., Phetchaburi Prov. Photos by Parinya Pawangkhanant. |
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| Figure 6. Morphological details of the male paratype of Microhyla tetrix sp. nov. (ZMMU A6034), male, in preservative. (a) Volar view of the left hand; (b) plantar view of the right foot. Drawings by Valentina D. Kretova. |
Microhyla tetrix sp. nov.
Diagnosis. The new species is allocated to the genus Microhyla Tschudi, 1838 based on the following combination of characters diagnostic for this genus (Parker 1934; Inger1989; Poyarkov et al. 2014, 2019): small body size; comparatively narrow head; eyes small with circular pupil; lack of small spine-like projection of skin at heel and elbow; maxillary and vomerine teeth absent; snout less than twice diameter of eye; tongue obovate, entire and free posteriorly; fingers without webbing; toes with basal webbing; palmar tubercles distinct; prominent inner and outer metatarsal tubercles on foot; supratympanic fold present; tympanum hidden under skin.
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Etymology. The specific name ‘tetrix’ is a Latin noun given in apposition derived from the Ancient Greek word ‘tettix’ (τεττιξ), meaning a grasshopper or cicada. The name is given in reference to the advertisement call of the new species, remarkably resembling a call of orthopterans, especially that of ground-hoppers of the family Tetrigidae. The recommended common name in English is ‘Tenasserim narrow-mouth frog’. The recommended common name in Thai is ‘Eung Jiew Tenasserim’ (อึ่งจิ๋วตะนาวศรี).
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| Spawning site of Microhyla tetrix sp. nov. at the type locality, showing a breeding male of Kaloula latidisca (in the middle) and Micryletta cf. lineata (bottom right) surrounded by numerous calling males and pairs in amplexus of the new species. Photo by Christian Hübner. |
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| Natural habitats of Microhyla in Thai-Malay Peninsula. (a) Breeding habitat of Microhyla tetrix sp. nov. at Klong Sok Dist., Surat Thani Prov., Thailand (type locality); (b, c) natural habitat of Microhyla superciliaris at Saba Yoi, Songkhla Prov., Thailand. Photos by Parinya Pawangkhanant (a-c) |
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| Microhyla superciliaris Parker from Saba Yoi, Songkhla Prov., Thailand, showing characteristic dorsal colouration and presence of an enlarged superciliary tubercle. (a) Adult male; (b) adult female (not collected). Photos by Parinya Pawangkhanant and Watinee Juthong. |
Nikolay A. Poyarkov, Parinya Pawangkhanant, Vladislav A. Gorin, Watinee Juthong and Chatmongkon Suwannapoom. 2020. A New Species of miniaturised Narrow-mouth Frog of the Genus Microhyla Tschudi, 1838 (Amphibia: Anura: Microhylidae) from northern Tenasserim, Thailand. Journal of Natural History. 54(23-24); 1525-1558. DOI: 10.1080/00222933.2020.1804005
