Oligodon cattienensis, Vassilieva, Anna B., Geissler, Peter, Galoyan, Eduard A., Poyarkov, Nikolay A., Devender, Robert Wayne Van & Böhme, Wolfgang, 2013
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publication ID |
https://doi.org/ 10.11646/zootaxa.3702.3.2 |
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publication LSID |
lsid:zoobank.org:pub:508E2367-560C-4FC5-9581-8FEB59EFDAC2 |
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DOI |
https://doi.org/10.5281/zenodo.6154495 |
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persistent identifier |
https://treatment.plazi.org/id/03B987A9-6862-C340-FF71-F9C3FD479665 |
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treatment provided by |
Plazi |
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scientific name |
Oligodon cattienensis |
| status |
sp. nov. |
Oligodon cattienensis sp. nov.
Oligodon cinereus (non O. cinereus Günther, 1864 )— Geissler, Nguyen, Poyarkov, Böhme, 2011
Holotype. ZMMU R – 13865 (field ID ZMMU NAP – 02281), adult male from the environs of Ben Cu forest station, Nam Cat Tien sector, Cat Tien National Park, Dong Nai Province, southern Vietnam (11°26' 03" N, 107° 25' 42" E, 130 m a.s.l.), collected by Anna B. Vassilieva on 20 January 2011.
Paratypes. ZMMU R – 13815 (field ID ZMMU NAP – 02165), adult male (roadkill) from type locality: Nam Cat Tien sector, Cat Tien National Park, Dong Nai Province, southern Vietnam (11°25' 43" N, 107° 25' 38" E, 148 m a.s.l.) collected on 13 March 2012 by Eduard A. Galoyan; ZMMU R – 13815 (field ID ZMMU NAP – 02189), subadult female from type locality (11°27' 03" N, 107° 21' 52" E, 167 m a.s.l.) collected on 04 April 2012 by Eduard A. Galoyan; ZMMU R – 13866 (field ID ZMMU NAP – 02240), adult male from type locality (11°26' 23" N, 107°25' 33" E; 143 m a.s.l.), collected on 17 December 2012 by Anna B. Vassilieva; ZMMU R – 11473, juvenile of undetermined gender from type locality, collected on 16 March 2003 by Vladimir V. Bobrov (preliminarily identified as Oligodon sp.); ZFMK 88921 (preliminarily identified as O. cinereus ( Geissler et al. 2011) , juvenile of unknown gender, from type locality (11°25' 43" N, 107° 25' 38" E, 148 m a.s.l.) collected by Robert Wayne Van Devender on 27 May 2009.
Diagnosis. A medium - sized Oligodon species, a member of the O. cyclurus group (fide Smith 1943, David et al. 2008b, Green et al. 2010) on the basis of the following morphological attributes: (1) deeply forked hemipenes without spines, (2) 17 - 17 - 15 dorsal scale rows, (3) 8 – 10 maxillary teeth, the posterior three being enlarged, (4) a complete head scalation complement, including a loreal but no presubocular, (5) an entire anal plate; and (6) a spotted and striped dorsal pattern. Oligodon cattienensis sp. nov. differs from all other members of the O. cyclurus group by the combination of the following morphological characters: (7) nasal entire; (8) 2 small postoculars, almost equal in size; (9) 167 – 178 ventrals; (10) 31 – 35 subcaudals; (11) tail relatively short (TaL/TL = 0.11 – 0.13); (12) 24 – 35 + 5 large dark - edged vertebral blotches in combination with a yellow - orange or red vertebral stripe between blotches; (13) head pattern including ocular band, temporal bands and elongated chevron; (14) ventrals pink or whitish (reddish in juveniles) in life, some bearing a quadrangular dark blotch on each lateral side, or ventrals being entirely dark.
Description of holotype. Body robust and cylindrical (362 mm SVL; 415 mm TL); head short (12.2 mm HL; HL/SVL = 0.03), broad and ovoid in dorsal view, faintly distinct from neck, somewhat depressed dorsoventrally; snout narrowed, triangle with blunt tip (4.6 mm SNL); mouth subterminal; large oval nostril piercing the central part of nasal; eye rather large (2.4 mm ED), about 0.2 times the head length; pupil rounded; tail rather short (53.0 mm TaL; TaL/TL = 0.13), ending in an acuminated tail cap.
Dentition. Maxillary teeth: 10 functional teeth on the right and 8 on the left side; two loci on left maxilla bear young, non - ankylosed teeth. The posterior three teeth are strongly enlarged, blade - like. Palatine dentition well developed.
Body scalation. DSR: 17 - 17 - 15, all smooth; outermost dorsal scale row enlarged; 167 VEN, strongly angulated; anal plate entire; 32 SC, all paired; terminal caudal scale forming an acuminated tail cap.
Head scalation. Head scalation (in dorsal view) comprising 1 rostral, 2 internasals, 2 prefrontals, 2 supraoculars, 1 frontal, and 2 parietals. Rostral large, wider than high, extending on to the dorsal surface of the snout and inserting deeply between internasals; internasals much wider than long, narrowing and slightly curving back towards the short median suture, about half as long as prefrontals; prefrontals large, pentagonal, wider than long, supraoculars pentagonal, elongated, about half as wide as long; frontal large, hexagonal, about 1.3 times longer than wide, posterior angle rather acute; parietals irregularly trapeziform, about twice larger than frontal, bordered posteriorly by 6 scales (including the third temporals); no enlarged nuchal scales present; (in lateral view) 1/1 entire elongated and waisted nasal (1.7 times longer than wide), pierced by a large nostril and subdivided medially in its lower half by a thin shallow suture; 1/1 squarish loreal scale; 8/8 supralabials: I. in contact with nasal, II. in contact with nasal and loreal, III. in contact with loreal and preocular, IV. and V. in contact with eye, VI. in contact with lower postocular and anterior temporal, VII. in contact with anterior temporal, VIII. in contact with lower posterior temporal, VI. and VII. being strongly enlarged; 1/1 narrow subrectangular preocular, in contact with eye, supraocular, prefrontal, loreal, III. and IV. supralabials; no presubocular; 2 small postoculars, almost equal in size; 1+2 temporals, anterior one pentagonal, elongated and narrow, upper posterior approximately equal to the anterior, elongated, lower posterior the smallest, rhomboid; (in ventral view) 8/8 infralabials, I. in contact with each other and with mental, I. toV. in contact with 2/2 enlarged chin shields; mental small, triangular; 2/2 enlarged, elongated chin shields, anterior pair being twice longer than posterior pair. For head scalation see Figure 1 View FIGURE 1 .
Coloration. In life. Body (see Figure 2 View FIGURE 2 ) is dull brownish gray; all dorsal scales scattered with minute dark brown spots; the three medial dorsal scale rows significantly less spotted, orange in color, with vertebral row slightly lighter, yellow - orange; 27 large transverse blotches on median dorsum, anterior six strongly waisted, butterfly - shaped, all posterior blotches have slight medial notch on the anterior and posterior ends; each blotch bluish - gray in its center, getting darker toward the edges, forming a thin dark - brown to black margin; those blotches continue (5) on tail; very faint dark reticulated crossbar between each pair of dorsal spots, up to the 13th spot; some lateral dorsal scales dark brown, forming scarce speckling on flanks; gular and anterior ventral scales white, posterior ventrals with light pinkish tint; some ventrals bearing a subrectangular, diffuse gray spot on each lateral margin; on the posterior third of venter, this darker spotting becomes denser; subcaudals white, with few tiny grayish marginal spots present on the proximal quarter of the tail; sharp edge between white tail underside and dark gray lateral dorsals; tail cap cream.
The head is rusty - orange dorsally, with paler snout sides and dark - edged olive - gray markings with maroon tint on upper surface of the head; an U - shaped interocular bar, being as wide as long, covering prefrontals as well as parts of frontal, supraoculars, preoculars and internasals and extending to the upper angle of rostral; supraoculars with an irregular, diffuse rounded blotch posteriorly; tear - shaped marking connected with the large arrow - shaped chevron extending from rear of frontal and medial part of parietals to the occiput and nape; 1/1 temporal bar with sharp, dark - edged anterior end and diffuse posterior one, starting on lateral parietals and running down towards the neck behind the jaw angle; two short dark gray, oblique subocular stripes extend backwards from the lower margin of each orbit, the anterior being more prominent and covering the parts of IV., V. and VI. supralabials, the posterior In preservative. See Figure 3 View FIGURE 3 . Body brownish - gray, vertebral region somewhat yellowish - beige; dorsal blotches and head markings dark gray, with a blackish margins; lateral speckling dark brown; throat, venter and tail undersides yellowish - cream, dark spots on ventral scales gray.
Description and variation of the paratype series ( Figures 4 View FIGURE 4 , 5 View FIGURE 5 , 6 View FIGURE 6 ). External morphology. The most important characters of the available specimens, all belonging to the type series, appear in table 1 (Appendix). All other morphological characters agree with those described for the holotype.
Dentition. 8 – 10 functional maxillary teeth in all specimens, the final three being strongly enlarged and blade - like; developed palatine dentition.
Body scalation. All scales are smooth, small, ovoid; first and second rows slightly enlarged, the vertebral row does not differ in size from other median dorsal rows. DSR: 17-17-15. Ventrals: 167–178, plus 1 (in one case 2) preventrals, strongly angulate; SC: 31 – 35, all paired; anal plate entire.
Head scalation. Generally as for holotype; in all specimens the entire nasal is subdivided below nostril by a thin shallow suture; single loreal and preocular, two postoculars, supralabials VI and V contacting eye; supralabials 8/8, infralabials 8/8 with one exception (7/7). Some variability observed in temporal scales, 1+2/1+2 being the most common condition (3 specimens), with primary (anterior) temporal being elongated subrectangular, secondary (posterior) upper temporal being elongated subrectangular approximately equal to the primary one, and lower secondary temporal being squarish, about half in length of the upper secondary temporal; the condition 1+1+2/1+1+2, with the two strongly elongated primary temporals being situated consecutively, observed in one specimen (ZFMK 88921); asymmetrical condition 2+3/2+ 2 in one specimen, with the upper primary (anterior) temporal representing elongated triangular scale shifted slightly anteriorly to the elongated subrectangular lower primary temporal, and the upper secondary (posterior) temporal on the right side of the skull divided on two smaller scales, anterior rounded and posterior triangular; asymmetrical condition 1+2/1+3 observed in one specimen, with the right side of skull similar to holotype and, on the left, with a small squarish scale between primary and upper secondary temporals.
Coloration in life. Ground coloration varies from lighter and darker grey or brown in adults and subadults to light reddish - brown in young juveniles (see Figure 4 View FIGURE 4 ); the pattern is more or less consistent with the holotype, with some variations in dorsal blotch number (24 – 35 on trunk, and always 5 on tail), and in the width of light vertebral stripe from one to three middorsal scale rows. Dorsal spots are dark bluish - gray in adults or subadults usually with little contrast (hardly distinguishable) with ground coloration of dorsum to dark brownish brick red, with a contrasting blackish margin in one juvenile (ZFMK 88921). Head marking is more contrasty in juvenile and subadult and includes a rounded spot on frontal separated from chevron in four individuals. Head markings are dark grey or olive - brown with maroon or rusty tint in adults and contrasty brownish - red in juveniles. Vertebral stripe varies from orange - yellow to red. Dark speckles on flanks may form oblique reticulated rows orientated back - and downwards. Ventral coloration varies from white with faint pinkish tint in adults to more saturated pink in subadults and bright red in juveniles (see Figure 5 View FIGURE 5 ); ventral pattern varies from few squarish dark - grey spots on lateral edges of some ventrals to almost continuous dark grey spotting on most posterior ventrals; the throat and most anterior ventrals are without dark spots; and at most a few tiny dark speckle in the proximal part of the tail.
Hemipenis (dissected in preserved specimen—adult male ZMMU R - 13866). The hemipenis is moderately long (reaching SC 11 – 12) and bifurcated opposite to SC 7 – 8. Proximal part of the unforked part is covered with deep calyces and few longitudinal folds, while distal part is smooth with thin and delicate longitudinal folds. Forks have faintly cellular surface. No spines or papillae are evident (see Figure 6 View FIGURE 6 ).
Distribution. Known only from the type locality (Cat Tien National Park).
Habitat and natural history. Specimens ZMMU R - 13865, R - 13866 and R - 13815 were collected on a country road running through highly disturbed lowland monsoon semideciduous, polydominant, partially submersible forest with the predominance of Lagerstroemia calyculata (Lythraceae) , Tetrameles nudiflora (Datiscaceae) , Dipterocarpus alatus (Dipterocarpaceae) , Ficus spp. ( Moraceae ) and Afzelia xylocarpa (Fabaceae) , and with a canopy formed by different arboreal species of Anacardiaceae , Lauraceae , Irvingiaceae , Meliасeae, Myrtaceae , Moraceae and Euphorbiaceae . Forest edges along the road are formed by bamboo ( Dendrocalamus sp.; Poaceae ), rattan ( Calamus sp., Arecaceae ), trees ( Terminalia calamansanai , Combretaceae ; Hibiscus sp., Malvaceae ; Grewia sp., Tiliaceae ; etc.), lianas ( Acanthaceae , Mimosaceae , Verbenaceae , etc.) and herbaceous plants ( Zingiber sp., Zingiberaceae ; Saccharum sp., Poaceae ; etc.). One specimen (ZMMU R - 13815) was collected on the forest trail in an almost undisturbed area of monsoon semideciduous forest with a strong predominance of Lagerstroemia calyculata and Tetrameles nudiflora .
Three living specimens were collected on the ground, being active during day time.
The digestive tracts of specimens ZMMU R - 13866 and R - 13815 contained chitinous remains of digested insects, presumably coleopterans and blattodeans.
Etymology. The new species is named after its type locality, the Cat Tien National Park. Established in 1978, and covering about 72.000 hectares, CTNP is one of the most important areas for the conservation of biodiversity of the lowland forests in southern Indochina.
Comparisons. In addition to hemipenial characters, which are unavailable in some species (Green 2010), we use the number of dorsal scale rows at midbody ( MSR) as a major diagnostic character for comparison (fide David et al. 2008 a & b). We compare Oligodon cattienensis sp. nov. ( MSR = 17) with all (distributional notes are provided for species not known from the Indochinese biogeographical region fide Bain & Hurley 2011) congeners having 15 to 17 MSR, as the number of MSR may vary between these two values due to the position of the dorsal scale row reduction (David et al. 2012). Among those, Oligodon cattienensis sp. nov. differs from the other members of the Oligodon cyclurus —group (sensu Smith 1943, David et al. 2008 a, and Neang et al. 2012) from: O. chinensis by an entire nasal, the presence of temporal bars, 24 – 35+5 large transverse blotches instead of 10 – 15+3 – 4 black crossbands, and the red ventral color in juveniles (greyish white in O. chinensis ); O. formosanus by an entire nasal, a reddish ventral coloration in juveniles (yellowish with a white ventrolateral line in O. formosanus ), and the presence of dark transverse vertebral blotches; O. kampucheaensis by an entire nasal, and 24 – 35+5 large vertebral blotches instead of 17 thin whitish transverse bands; O. kheriensis from India by a lower number of VEN (167 – 178 vs. 196), the presence of a chevron as well as the presence of vertebral blotches (dorsum being uniformly colored in O. kheriensis ); O. macrurus by an entire nasal, a higher number of VEN (167 – 178 vs. 139 – 162), and a lower number of SC (31 – 35 vs. 45 – 94); O. saintgironsi by an entire nasal, 1 vs. 2 PreOc, 31 – 35 vs. 53 – 59 SC, and 24 – 35+5 vs. 10 – 13+2 – 4 large transverse blotches on dorsum. Further species assigned to the O.cyclurus – group are differing by having 19 or more MSR: O. cyclurus (19 MSR); O. fasciolatus (21 – 23 MSR); O. juglandifer from Northeast India (19 MSR); O. ocellatus (19 MSR). Beyond its own species group, O. cattienensis sp. nov. differs from: O. affinis from India by a higher number of ventrals (167 – 178 vs. 129 – 145) and an undivided nasal; O. ancorus from the Philippines by a higher number of vertebral blotches (24 – 35 +5 vs. 14 – 22), and a red ventral coloration in juveniles (yellowish cream in O. ancorus ); O. annulifer from Borneo by an entire nasal, a higher number of VEN (167 – 178 vs. 151 – 162), a lower number of SC (31 – 35 vs. 44 – 50), and 8 (rarely 7 IL) instead of 7 SL and IL; O. arnensis from the Indian Subcontinent by an entire nasal, 8 (rarely 7 IL) instead of 7 SL and IL, and an entire anal plate; O. barroni by an entire nasal, a higher number of VEN (167 – 178 vs. 135 – 160), 24 – 35+5 vs. 10 – 14 transverse paravertebral blotches; O. bitorquatus from Indonesia by an entire nasal, 8 (rarely 7 IL) instead of 7 SL and IL, and the absence of a bright yellow collar between the temporal bars and the chevron; O. booliati from Pulau Tioman by an entire nasal, 2 instead of 1 PosOc, a higher number of VEN (167 – 178 vs. 143 – 153), and a lower number of SC (31 – 35 vs. 54 – 60); O. brevicauda from India by an entire nasal, the presence of a loreal, 8 (rarely 7 IL) instead of 7 SL and IL, and the presence of dark vertebral blotches; O. cinereus by an entire nasal, by a head bearing prominent dark markings (temporal bars, chevron, interocular bar), and a red ventral coloration in juveniles (white to yellowish cream in O. cinereus ) [ Bourret (1934) described Simotes violaceus pallidocinctus from Saigon. This name “pallidocinctus” is currently recognized as a color form of O. cinereus (see Green 2010, David et al. 2012). This color form occurs syntopically with Oligodon cattienensis sp. nov. and is distinguishable by its characteristic 27 – 34+3 – 4 light, black edged, thin crossbars and unspotted ventrals]; O. cruentatus from Southern Myanmar by an entire nasal, and a divided anal plate; O. deuvei by an entire nasal, 1 instead of 2 PreOc, absence of a light vertebral line edged by two darker dorsolateral lines, and a reddish ventral color in juveniles (only ventral tail being red in O. deuvei ); O. dorsalis from Assam, Bhutan, Bangladesh and Myanmar by 2 instead of 1 PosOc, 8 (rarely 7 IL) instead of 7 SL and IL, and an undivided anal plate; O. erythrogaster from India and Nepal by the presence of a loreal, 8 (rarely 7 IL) instead of 7 SL and IL, an entire anal plate, and the presence of transverse vertebral blotches; O. erythrorhachis from India by the presence of a loreal, an entire anal plate, a higher number of VEN (167 – 178 vs. 154), and a lower number of SC (31 – 35 vs. 46); O. everetti from Borneo by an entire nasal, 8 (rarely 7 IL) instead of 7 SL and IL, a higher number of VEN (167 – 178 vs. 132 – 154), and a lower number of SC (31 – 35 vs. 46 – 72); O. forbesi from Indonesia by an entire nasal, a lower number of SC (31 – 35 vs. 43 – 51), the presence of an ocular bar and a reddish ventral color in juveniles (yellowish in O. forbesi ); O. hamptoni from Myanmar by the presence of two internasals, 8 instead of 5 SL, 8 (rarely 7) IL instead of 6 IL, and an entire anal plate; O. inornatus by an entire nasal, the presence of prominent head markings (chevron, temporal bars and ocular bar), and the presence of 24 – 35+5 large vertebral blotches (head and body uniformly pale brown in O. inornatus ); O. jintakunei from Thailand by an entire nasal, presence of 2 internasals, 2 instead of 1 PosOc, and an entire anal plate; O. joynsoni by an entire nasal, a lower number of VEN (167 – 178 vs. 187 – 195) and of SC (31 – 35 vs. 40 – 50); O. kunmingensis from China by an entire nasal, the presence of a loreal, 8 instead of 5 SL, 8 (rarely 7) IL instead of 6 IL, and a higher number of VEN (167 – 178 vs. 108 – 121); O. lacroixi by the presence of 2 internasals, the presence of a loreal, 8 instead of 5 SL, 8 (rarely 7) IL instead of 6 IL, and an entire anal plate; O. lungshenensis from China by the presence of two intranasals, the presence of a loreal, 8 (rarely 7 IL) instead of 6 SL and IL, and an entire anal plate; O. maculatus from the Philippines by 8 (rarely 7 IL) instead of 7 SL and IL, a higher number of VEN (167 – 178 vs. 156 – 164) and a lower number of SC (31 – 35 vs. 52 – 55); O. melaneus from India by an entire anal plate, a higher number of VEN (167 – 178 vs. 152 – 160) and a lower number of SC (31 – 35 vs. 39 – 40); O. melanozonatus from India and China by the presence of a loreal, 8 (rarely 7 IL) instead of 6 SL and IL (7 SL present in one specimen of O. melanozonatus ), and by an entire anal plate; O. meyerinkii from the Philippines and Borneo by an entire nasal, by 8 (rarely 7 IL) SL and IL (6 SL and 7 IL in O. meyerinkii ), and by the absence of paravertebral stripes; O. modestus from the Philippines by 2 instead of 1 PosOc, by 8 SL and IL (6 SL and 7 IL in O. modestus ), and by the presence of large transverse blotches on dorsum; O. moricei by an entire nasal, by a reddish to greyish dorsal coloration with large transverse blotches instead of a dark greyish brown color with only a lighter vertebral line, and a reddish venter (in juveniles) instead of a yellowish one in O. moricei ; O. mouhoti by an entire nasal, and the absence of a light vertebral line flanked by brown lines (vertebral line interrupted by dark transverse blotches in O. cattienensis sp. nov.); O. multizonatus from China by an entire nasal, by a short loreal not touching the eye, a lower number of VEN (167 – 178 vs. 190 – 195) and SC (31 – 35 vs. 68 – 75), and an entire anal plate; O. nagao by 1 instead of 2 PreOc, a lower number of VEN (167–178 vs. 184–193) and SC (31–35 vs. 43–47), a forked hemipenes and a yellow - orange or red vertebral stripe between blotches; O. nikhili from India by an entire nasal, the presence of a loreal, a higher number of VEN (167 – 178 vs. 144), and an entire anal plate; O. notospilus from the Philippines by a higher number of VEN (167 – 178 vs. 136 – 140); O. octolineatus from Malaysia, Singapore and Indonesia by an entire nasal, the absence of alternating longitudinal stripes on dorsum, and the presence of a broad V - shaped chevron; O. ornatus from Taiwan and China by the presence of a loreal, 8 (rarely 7 IL) instead of 7 SL and IL, and an entire anal plate; O. perkinsi from the Philippines by a lower number of VEN (167 – 178 vs. 183 – 188), and by the presence of prominent head markings (ocular bar, temporal bars and chevron); O. petronellae from Sumatra by 8 (rarely 7 IL) instead of 7 IL and SL, a higher number of VEN (167 – 178 vs. 144 – 163), and the absence of 20 – 25+3 – 5 lighter rings; O. praefrontalis from Indonesia by the presence of 2 internasals and a loreal, 2 instead of 1 PosOc, a lower number of VEN (167 – 178 vs. 193), and an entire anal plate; O. propinquus from Indonesia by 8 (rarely 7 IL) instead of 7 SL and IL, 167 – 178 vs. 140 VEN, and the presence of distinct head markings (ocular bar, temporal bars and chevron); O. pseudotaeniatus from Thailand by an entire nasal, a higher number of VEN (167 – 178 vs. 137 – 156), and the presence of dark transverse blotches on dorsum; O. pulcherrimus from Sumatra by an entire nasal, and an entire anal plate; O. signatus from Malaysia, Singapore and Indonesia by an entire nasal, 2 vs. 1 PosOc, and 31 – 35 vs. 43 – 59 SC; O. sublineatus from Sri Lanka by an entire nasal, an entire anal plate, and 8 (rarely 7 IL) vs. 7 SL and IL; O. taeniolatus from the Indian Subcontinent, Iran, Afghanistan, Turkmenistan and Sri Lanka by an entire nasal, and an entire anal plate; O. templetoni from Sri Lanka by an entire nasal, 167 – 178 vs. 127 – 152 VEN, and an entire anal plate; O. theobaldi from Assam and Myanmar by an entire nasal, an entire anal plate, and the absence of longitudinal lateral lines; O. torquatus from Myanmar by an entire anal plate, and the absence of 4 dark longitudinal stripes on dorsum; O. travancoricus from India by an entire nasal, the presence of a loreal, a higher number of VEN (167 – 178 vs. 145 – 155), and an entire anal plate; O. trilineatus from Sumatra region by an entire nasal, 2 vs. 1 PosOc, 167 – 178 vs. 145 – 162 VEN, 31 – 35 vs. 39 – 62 SC, and the presence of dark transverse blotches on dorsum; O. unicolor from Indonesia by an entire nasal, 8 vs. 6 SL, and the presence of large dorsal blotches; O. venustus from India by an entire anal plate, and 8 (rarely 7 IL) vs. 7 SL and IL; O. vertebralis from Borneo and the Philippines by an entire nasal, 8 (rarely 7 IL) vs. 7 SL and IL, and by a higher number of VEN (167 – 178 vs. 136 – 154); O. waandersi from Sulawesi Archipelago by the absence of a prominent reddish vertebral line on tail; O. wagneri from Pulau Nias by an entire nasal, by 24 – 35+5 large transverse dorsal blotches instead of 14 narrow white crossbars, and by a reddish venter (in juveniles); O. woodmasoni from Andaman and Nicobar Islands by an entire nasal, 167 – 178 vs. 180 – 190 VEN, and a lower number of SC (31 – 35 vs. 46 – 57). Comparative data used in this paragraph are based on: Green (2010); Green et al. (2010); David et al. (2008 a & b); David et al. (2012); David & Vogel (2012); Neang et al. (2012); Campden - Main (1970); Saint Girons (1972); Deuve (1970); Geissler et al. (2011, 2012); Murthy et al. (1993).
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