Hypnale
Creators: name: Maduwage, Kalana
name: Silva, Anjana
name: Manamendra-Arachchi, Kelum
name: Pethiyagoda, Rohan
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Reptilia
Squamata
Viperidae
Hypnale

description: Hypnale species ‘amal’
(Fig. 8; Fig. 9; Table 2)
Material examined. WHT 7140 male, 325 mm SVL, Watareka, Galle, Sri Lanka, 06º04’N, 80º12’ E, alt. 10 m, coll. Amal Wijesekara, 25 XI 2006.
Diagnosis. Hypnale sp. ‘amal’ is distinguished from its congeners by a combination of the following characters: tip of snout not raised; no wart-like protuberance on snout-tip (Fig. 8 a); 3 minute scales between rostral and base of internasals (Fig. 8 b). Ten small heterogeneous scales on internasal-prefrontal region (Fig. 8 b); 6 scales around eye: supraocular + 2 postoculars + 2 preoculars + postfoveal (Fig. 8 a); 4 scales encircle maxillary pit: lower preocular + postfoveal + lacunal + upper edge of 2nd supralabial (Fig. 8 a); 2 postoculars, the upper one small, the lower one crescentic, reaching postfoveal; no small scales between postfoveal and 3rd supralabial (Fig. 8 a); lower postocular, 1st lower temporal, 4th and 5th supralabials in contact, no scale between them; supralabials 9; lacunal present, surrounded by loreal, 1st supralabial, 2nd supralabial, maxillary pit and tip of lower preocular); 1st infralabials on left and right side medially fused, not separated from each other by a median suture (Fig. 8 c); costal scales keeled (Fig. 8 d); ventrals 151; subcaudal series divided medially, with 41 scales; hemipenial lobe not spinous.
Hypnale sp. ‘amal’ is distinguished from H. hypnale by having 9 (vs 7–8) supralabials; the first infralabials on either side medially fused (vs separated from each other by a median suture); and a distinct, purple-brown paravertebral stripe about 3 scales wide extending from neck to level of vent (vs two rows of distinct, bilaterally symmetrical sub-oval or sub-triangular blotches meeting on dorsal midline).
It is distinguished from H. nepa by lacking (vs possessing) a wart-like protuberance on the snout-tip; lacking (vs possessing 1–3) scales between the postfoveal and 3rd supralabial; having the lower postocular, 1st lower temporal, 4th and 5th supralabials in contact (vs separated by a rhomboid scale of similar size); 9 (vs 7–8) supralabials; the first infralabials on either side medially fused (vs separated from each other by a median suture); all costal scales keeled (vs mid-dorsal scales smooth); 151 (vs 122–134) ventrals; the hemipenial lobe not spinous (vs spinous on proximal two-thirds of its length); a distinct purple-brown paravertebral stripe about 3 scales wide extending from neck to level of vent (vs two rows of distinct, sub-oval or sub triangular bilaterally symmetrical blotches meeting on dorsal midline).
It is distinguished from H. zara by having the tip of the snout not raised (vs distinctly elevated); lacking (vs possessing) a wart-like protuberance on the snout-tip; having 10 (vs 18–39) small heterogeneous scales on internasal-prefrontal region; 4 (vs 3) scales encircling maxillary pit; 9 (vs 7–8) supralabials; a lacunal scale present (vs absent); first infralabials on either side medially fused (vs not fused, separated from each other by a median suture); and a distinct purple-brown paravertebral stripe about 3 scales wide extending from neck to level of vent (vs 2 rows of distinct, bilaterally symmetrical blotches meeting on dorsal midline).
Description. Based on only known specimen, WHT 7140. Snout tip not raised (Fig. 8 a); no wart-like protuberance on snout tip. Three small scales between rostral and base of internasals (Fig. 8 b); about 14 small, heterogeneous scales on internasal-prefrontal region (damaged: see Fig. 8 b); internasals small, distinct; prefrontals distinct, somewhat displaced; internasals broadly separated from one another by a small scale; prefrontals in contact, separated from frontal and supraoculars by 5 rows of small scales; upper preocular, loreal and nasal extend over canthal ridge, just visible from above; rostral longer than wide, obtusely pointed, scarcely visible from above; nasal partially divided above level of nostril; loreal acutely pointed anteriorly, its posterior margin broad, extending dorsally across canthus; 2 preoculars; 2 postoculars, the upper one small, the lower one crescentic, reaching postfoveal; eye encircled by 6 scales: 2 preoculars + supraocular + 2 postoculars and postfoveal (Fig. 8 a); lacunal scale present. Maxillary pit bordered by 4 scales: lacunal, lower preocular, postfoveal and upper edge of 2nd supralabial. Supralabials 9, not in contact with eye; 1st supralabial extends upward to reach loreal; apex of 1st supralabial not divided into a small scale; infralabials 9 on left and 8 on right (Fig. 8 c). Four rows of smooth temporals, those on lower row greatly enlarged; postparietals numerous, small. Mental subtriangular; a single pair of chin shields, longer than wide; infralabials I, II and III in contact with chin shields (Fig. 8 c). Mental and chin shields separated from each other by infralabial I; 1st infralabials on left and right side fused, not separated from one another by a median suture (Fig. 8 c); gular scales in 4 medial series, 6 lateral series.
Costodorsal reduction (WHT 7140):
4+3(8) 5+4(140)
19————–17—————15 (145)
5+4(7) 3+4(142)
Costal scales at mid-body 17; paravertebral scale row not enlarged; dorsal scales keeled except for those on lowermost 3 lateral rows; paired apical pits present, inconspicuous. Ventrals 151; subcaudal series divided medially, with 41 scales; anal scale partially divided; 2 pairs of sub-anal scales. Rows of costal scales up to 8th ventral on right side and 7th ventral on left, 19; 17 rows thereafter (including mid-body) up to 140th ventral on right side and 142nd on left, following which 15 rows up to anus.
The hemipenes of the male holotype are not everted, and were examined following dissection. Hemipenes moderately long, slender, deeply forked, without spines. Transverse flounces closely spaced on lobes; sulcus spermaticus deep.
Mensural data (see also Table 2). Measurements of only known specimen: SVL, 325 mm; TL, 59 mm, (18.2% of SVL); HL, 18.0 mm (5.5% of SVL); HW, 12.0 mm (66.7% of HL); SL, 5.0 mm (27.8% of HL); FL, 3.4 mm (18.9% of HL); FW, 2.7 mm (15.0% of HL); PL, 4.6 mm (25.6% of HL); PW, 3.2 mm (17.8% of HL); SU, 4.4 mm (24.4% of HL); SW, 3.8 mm 21.1% of HL); SS, 2.9 mm (16.1% of HL).
Coloration. (Based on in vivo observations of the only known specimen.) Dorsal ground colour light brown, with minute, closely-spaced dark-brown spots on body. Head purplish-brown dorsally. A distinct purple-brown paravertebral stripe extends from neck to level of vent, about 3 scales wide, becoming diffuse on tail; keels on paravertebral scales yellow, forming a fine mid-dorsal line that extends from mid-body to level of vent (Fig. 9 a). Tip of tail yellow-brown. A distinct, yellow-brown dorsolateral stripe originates from snout and traverses upper half of cheek and eye over about the anterior one-fourth of body length, becoming progressively diffuse on lower costal rows; a dark-brown stripe beneath this, traversing lower half of eye and rest of cheek, gradually becoming diffuse in region of lower costals. Labials paler than ground colour; supralabials II and III whitish. Medial gulars pale brown; lateral gulars dark brown. Ventrals pale brown with fine coffee-brown pigmentation.
Natural history notes. The specimen was collected from a shaded home garden (Fig. 9 b), within about 50 m of a small stream about 3 km upstream of the sea. It was taken by Mr Amal Wijesekera (pers. comm.), who maintained it in captivity for two weeks, during which it was photographed by the collector and A. I. Alagiyawadu (Fig. 9 a), after which it died, perhaps as a result of its heavy nematode infestation. Extensive searches in the vicinity of the collection locality during the first half of 2007 failed to uncover any further specimens.
description: Published as part of Maduwage, Kalana, Silva, Anjana, Manamendra-Arachchi, Kelum & Pethiyagoda, Rohan, 2009, A taxonomic revision of the South Asian hump-nosed pit vipers (Squamata: Viperidae: Hypnale), pp. 1-28 in Zootaxa 2232 on pages 20-21, DOI: 10.5281/zenodo.190308