Aspidura desilvai Mendis Wickramasinghe & Bandara & Vidanapathirana & Wickramasinghe 2019, sp. nov

Autor: Mendis Wickramasinghe, L. J., Bandara, Imesh Nuwan, Vidanapathirana, Dulan Ranga, Wickramasinghe, Nethu
Rok vydání: 2019
Předmět:
DOI: 10.5281/zenodo.5929493
Popis: Aspidura desilvai sp. nov. (Figures 1���7) Holotype. NMSL-NH 2019.01.0 2, adult male, 168 mm SVL (Figure 2), from Riverstone, Knuckles, Matale District, Central Province, Sri Lanka (07��31���39��� N, 80��44���01��� E, elevation 1420 m). Collected by L.J.M. W and D.R.V. on 0 7 July 2018. Paratypes. NMSL-NH 2019.01.0 1, adult female, 208 mm SVL, from Panwila in Knuckles Mountain Range, Kandy District, Central Province in Sri Lanka (07��22'00.36������ N, 080��41'00.10������ E, elevation 995 m). Collected by L.J.M. W and I.N.B. on 13 March 2011; DWC 2019.05.0 1, adult female, 157 mm SVL, from Dotulugala, Knuckles Mountain Range, Kandy District, Central Province, Sri Lanka (07��27'00.30��� N, 080��45'00.20��� E, elevation 1700 m). Collected by L.J.M. W and I.N.B. on 17 March 2011; DWC 2019.05.0 2, juvenile male, 93 mm SVL, from Gombaniya Mountain, Knuckles Mountain Range, Matale District, Central Province, Sri Lanka (07��27'51.76������ N, 080��45'51.79������ E, elevation 1375 m). Collected by L.J.M. W and I.N.B. on 13 March 2011. Diagnosis. SVL 94���216 mm; snout to eye distance 2.5 times the eye width (SE/EW); prefrontals touching eye; preocular small, does not touch supraocular; postoculars 2, lower one larger than the upper; temporal 1+2/1+2; supralabials 6/6, 4 th touching eye; infralabials 6/6, first pair in contact, progressively increasing in size from 1 st to 6 th; anterior chin shields 2, large, touching 1���4 infralabials; posterior chin shields 2, anterior half in contact while the posterior half separated by 1 st ventral; ventrals 124���139; subcaudals 16���29; dorsal scale rows 15���15���15; laterally spine like tubercles present on two scale rows nearest to the subcaudals of the ischiadic, anal and tail base regions in adult males, feeble in juvenile males, and absent in females; entire dorsum brown colour, much paler towards anterior; three irregular dotted lines on dorsum. Description of holotype. Adult male; SVL 168 mm; TaL 25.1 mm; TL 193.1 mm; TaL/TL 0.13; body elongate and cylindrical; head short (SVL/HL 18.3), elliptical, indistinct from thick neck; snout long, narrowing anteriorly, pointed in dorsal aspect, snout to nostril distance about 2.8 (EW/SN) times as long as nostril width; nasal divided; small, triangular nostril, touching divided nasal and first supralabial, not touching rostral; eye larger than horizontal diameter of nostril, distance between snout to eye about 2.6 (SE/EW) times the eye width, round pupil; snout to eye distance 0.3 times head length (SE/HL); tail short (TaL/SVL 0.1), robust at its base, tapering progressively to a single point. Head scalation. Head scalation includes 1 internasal, 2 prefrontals, 2 supraoculars, 1 frontal, and 2 parietals (Figure 3A). Rostral small, convex, wider than long and rounded in lateral, dorsal and ventral aspects. Nasal vertically divided by a groove above nostril (Figure 3B). Internasal large, irregular hexagonal; widely in contact with prefrontals. Two large prefrontals, longer and wider than internasals, largest distance along the longitudinal axis of prefrontals shorter than frontal (Figure 3A) in length, anterior-most corner of prefrontals touching nasal, bordered by 2 nd and 3 rd supralabial, preocular scale, eye, supraocular and frontal. Preocular small, not in contact with supraocular. Loreal and subocular scales absent. Supraocular smaller than frontal. Two postoculars, lower one larger than upper. Two parietals; largest scales on head. Temporals 1+2/1+2. Supralabials 6/6, 4 th touching eye, progressively increasing in size from 1 st to 6 th (Figure 3B). Mental small and triangular, wider than long. Infralabials 6/6, first pair in contact, progressively increasing in size from 1 st to 6 th. Anterior chin shields 2, large, touching 1���4 infralabials. Posterior chin shields 2, anterior half in contact, posterior portion separated by 1 st ventral (Figure 3C). Body scalation. Ventrals 124, 1 st ventral longer than wide; subcaudals 24, all single; anal single and large; dorsal scale rows 15���15���15; laterally prominent spine like tubercles present on two scale rows nearest to the subcaudals, and its protrusion reducing towards upper scale rows in the ischiadic, anal and tail base regions (Figure 4); vertebral rows and first coastal not enlarged; no apical pit. Hemipenis morphology. Based on Holotype specimen: right everted hemipenis extends for length of 3 subcaudals. Everted organ single subcylindrical, globular, sulcus spermaticus simple. Basal to apex region bearing prominent spines which are evenly distributed and are in uniform length (Figure 5). Colour in life. Supralabials and infralabials light yellow, with dark margins separating each scale (Figure 6A). Entire dorsum reddish brown colour, much paler towards anterior and each scale having tiny dark spots (Figure 2). Three irregular dotted lines on dorsum (Figure 6B). These are symmetrically placed and continues from neck to tail end. Prominent light brown stripe continues dorsolaterally from neck to tail end, marked due to much darker regions which constitutes of dotted lines below and above this region. These lines continue from neck to tail end. Venter primarily peach, with black blotching all over; gular region yellow. Colour in alcohol. Colour pattern remains unchanged. Pupil changes to off white. Darker regions fades to a light brown. Variations in colour. In an unpreserved male specimen (Figure 7D) except the head region and ventre the entire body was black. Natural History. Aspidura desilvai sp. nov. have been observed commonly in its habitat (Figure 1). The species is confined to Knuckles conservation area, and is found in and above the lower montane forests of Knuckles. Authors have observed the snake from 995 m up to 1700 m above sea level (Figure 8). The habitat of A. desilvai sp. nov. is closed canopy forests dominated by Syzigium sp. (Figure 9). The moist-cooler habitat is densely occupied with large and medium sized trees which are heavily covered with epiphytes. No direct sunlight falls to the forest floor, and the undergrowth was not well established where the individuals were found. Relatively thin litter cover was observed in the habitat. Commonly observed under leaf litter and loose soil while they were also observed under rocks, boulders, and decaying logs. Individuals come out to the surface during the day time. Reddish brown latosolic soil in the locality is more or less similar to the body colour of the snake. Etymology. The species is named in honor of Pilippu Hewa Don Hemasiri de Silva (Dr. P. H. D. H. de Silva), a former Director (1965-1981) of the National Museums of Sri Lanka. In recognition of his tireless services to the country, while in service and through his many publications specially as the author of the book titled ��� Snake Fauna of Sri Lanka, with special reference to skull, dentition and venom in snakes ���. The species epithet desilvai is a noun in the genitive case. Suggested common names. desilvage madilla, and de Silva���s Rough-Side Snake in native Sinhala language and English language respectively. Comparison. The new species was compared with all known congeners of the genus Aspidura and the species most closely resembles A. ravanai, and A. trachyprocta, due to the following combination of characters: one preocular, two postoculars, 1+2 temporals, supralabials 6, 4 th supralabial in contact with the eye, infralabials 6, coastals 15, single cloacal scale, and overlapping ventral and subcaudal counts, but can easily be distinguished by the following morphological characters: from A. ravanai: entire dorsum brown colour, much paler towards anterior and each scale having tiny dark spots in Aspidura desilvai sp. nov. (vs. entire dorsum jet black in Aspidura ravanai), ventrolaterally darker region which constitutes of irregular longitudinal dotted lines (vs. ventrolaterally an irregular longitudinal yellow stripe), laterally prominent spine like tubercles present on two scale rows nearest to the subcaudals, and its protrusion reducing towards upper scale rows (vs. entire coastal rows coarsely keeled, with 1���3 peaks on each scale) in males (Figures 4 & 10 A���C), entire coastal rows of the ischiadic, anal and tail base regions smooth (vs. feebly keeled) in females, snout to eye distance about 2.5 times its eye width (vs. 3.2 times in A. ravanai) (Figures 3 & 10 D���E); from Aspidura trachyprocta: entire dorsum brown colour, much paler towards anterior and each scale having tiny dark spots in A. desilvai sp. nov. (vs. reddish-yellow to brown with a longitudinal black stripe on mid dorsum in Aspidura trachyprocta), ventrolaterally darker region which constitutes of irregular longitudinal dotted lines (vs. black stripe), laterally prominent spine like tubercles present on two scale rows nearest to the subcaudals, and its protrusion reducing towards upper scale rows (vs. bulging spine like tubercles prominent laterally which reduces towards dorsum) of the ischiadic, anal and tail base regions in males (Figures 4 & 11 A���C), entire coastal rows of the ischiadic, anal and tail base regions smooth (vs. feebly keeled) in females, snout to eye distance about 2.5 times its eye width (vs. twice in A. trachyprocta) (Figures 3 & 11 D���E); from A. brachyorrhos Boie, 1827, by having 15 coastals (vs. 17), preocular not in contact with supraocular (vs. contact), prefrontal contact with eye (vs. separate), single subcaudals (vs. paired); from A. copei G��nther, 1864 by having coastals 15 (vs. 17), single subcaudals (vs. paired), single preocular (vs. absent); from A. deraniyagalae Gans & Fetcho, 1982 by having 15 coastals (vs. 17), ventrals 124���139 (vs. 117���122), single subcaudals (vs. paired); from A. drummondhayi Boulenger, 1904, by having single subcaudals (vs. paired), single preocular (vs. absent); from A. guentheri Ferguson, 1876 by having 15 coastals (vs. 17), ventrals 124���139 (vs. 100���127); from A. ceylonensis (G��nther, 1858), by prefrontal touching eye (vs. not touching eye), preocular does not touch supraocular (vs. touches), lower postocular larger than the upper (vs. vise versa), mid body coastals not keeled (vs. coarsely keeled).
Published as part of Mendis Wickramasinghe, L. J., Bandara, Imesh Nuwan, Vidanapathirana, Dulan Ranga & Wickramasinghe, Nethu, 2019, A new species of Aspidura Wagler, 1830 (Squamata: Colubridae: Natricinae) from Knuckles, World Heritage Site, Sri Lanka, pp. 265-280 in Zootaxa 4559 (2) on pages 266-272, DOI: 10.11646/zootaxa.4559.2.3, http://zenodo.org/record/2626972
{"references":["Boie, F. (1827) Bemerkungen uber Merrem's Versuch eines Systems der Amphibien. Marburg. 1820. Erste Lieferung: Ophidier. Isis von Oken, 20 (10): col. 508 - 566.","Gunther, A. (1864) The Reptiles of British India. Taylor & Francis, London, xxvii + 452 pp.","Gans, C. & Fetcho, J. R. (1982) The Sri Lankan genus Aspidura (Serpentes, Reptilia, Colubridae). Annals of the Carnegie Museum, 51 (14), 271 - 316.","Boulenger, G. A. (1904) Description of a new snake (Aspidura drummondhayi). Spolia Zeylanica, 2 (7), 95 - 96.","Ferguson, W. (1876) Description of a new snake of the genus Aspidura from Ceylon. Proceedings of the Zoological Society of London, 819 - 820. https: // doi. org / 10.1111 / j. 1096 - 3642.1876. tb 02619. x","Gunther, A. (1858) Catalogue of Colubrine snakes of the British Museum. London, xvi + 281 pp."]}
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