Trimeresurus gunaleni, Vogel & David & Abstract.-Variation, 2014

Vogel, Gernot, David, Patrick & Abstract. - Variation, Irvan Sidik, 2014, On Trimeresurus sumatranus (Raffles, 1822), with the designation of a neotype and the description of a new species of pitviper from Sumatra (Squamata: Viperidae: Crotalinae), Amphibian & Reptile Conservation 8 (2), pp. 1-29 : 15-17

Description and Variation of T. sumatranus ( Fig. 5–9 )

According to Brongersma (1933), Sanders et al. (2002), Gumprecht et al. (2003), Das (2010), and our material, this large species reaches a maximum total length of 1,355 mm. Gumprecht et al. (2003) mentioned a total length of 1,400 mm. Males are seemingly shorter, the longest male seen by us being only 878 mm long. Adults reach usually a maximum total length of 90–110 cm.

The body is robust but elongate in both males and in females, or slightly thinner in males. In adults, the snout is 24.0–28.0% as long as head or 1.8–2.6 times as long as diameter of eye. Eye average, amounting for 0.6–1.0 times the distance eye–lower edge of the lip in both sexes. Ratio TaL/TL: 0.128 –0.168, with a weak sexual dimorphism: males: 0.150 –0.168; females: 0.128 –0.160.

Hemipenis

After Gumprecht et al. (2004: 304: Fig. IV), hemipenes are long and slender, deeply forked, extending up to twenty-secondth subcaudal, forked opposite ninth subcaudal, smooth at its base and after the forking point, for about a third of the organ, then strongly papillose and spinose, with longitudinal folds.

Body scalation

DSR: 21–25 one head length posterior to the head; 21 (exceptionally 23) at midbody; 15 (exceptionally 13 or 17) scales one head length before vent, weakly or distinctly keeled, smooth on first DSR; VEN: 175–191 (plus 1–2 preventrals); SC: 54–68, all paired, with a sexual dimorphism (males: 66–71; females: 54–68); anal entire.

In our sample of 44 specimens, we have not examined any specimen with 23 DSR at midbody but this value has been recorded in the literature by Brongersma (1933) from a specimen from Borneo. In our material, two specimens had 13 scale rows before vent and only one had 17 rows before vent .

Head scalation

Rostral barely visible from above, triangular, wider than high; nasals subrectangular, divided; one large, subrectangular or nearly square internasal on each side; internasals usually separated by one scale or in contact (in 11/44 examined specimens); two (rarely three) canthal scales bordering the canthus rostralis, one larger than the large adjacent snout scales and one (or two) of similar size; two (exceptionally one) postoculars on each side; one very large and wide supraocular on each side, about 1.8–2.2 times as long as wide, 1.0–1.3 times as wide as internasal, not indented by adjacent cephalic scales; 4–7 much enlarged scales on upper snout surface on a line between the scale separating the internasals and a line connecting the anterior margins of eyes, smooth and juxtaposed; 3–7 (usually 5–6) cephalic scales on a line between supraoculars, large, smooth, flat, and juxtaposed; occipital scales larger than cephalic scales, smooth; temporal scales smooth, large, subequal, in two rows anteriorly, three rows posteriorly; 8–11 (usually 9–10) supralabials; first SL always separated from nasal; second SL tall, entirely bordering the anterior margin of the loreal pit, always in contact with nasal; third SL longest and highest, 1.1–1.4 times as long as high, always in contact with subocular; fourth SL as long as high, as high or barely shorter than third SL, always in contact with subocular; fifth SL usually in contact with subocular, exceptionally separated by one scale (on one side in 3/ 44 specimens); 9–15 (usually 10–12) IL; scales of the first pair longitudinally in contact or barely separated by the apex of the long mental scale; first two or three pairs of infralabials in contact with anterior chin shields; 5–9 rows of smooth gular scales; throat shields irregularly arranged .

Coloration and pattern

In live adult specimens, the dorsum is yellowish-green, grass green, deep emerald green, or olive green (deep green, bluish-green, or dark brown in preservative); many scales of the body narrowly edged with black; usually a series of about 45–50 irregular, black crossbars one or two dorsal scales in length, reaching downwards to the third or second dorsal scale rows on each side of the body. These crossbands are either symmetrical, forming black rings, or offset from each other on each side of the vertebral line. Each crossbar includes one or two entirely black scales, the other dorsal scales are strongly edged in black. The interstitial skin between the large dorsal scale is also black, making an overall distinctly barred and reticulate pattern. A more or less conspicuous, cream, greenish-yellow, or pale yellow ventrolateral stripe on the first and lower half to whole of the second dorsal scale rows, extends from the base of the neck to the vent. This pale stripe is bordered below by a narrow dark stripe created by the black edge of the outer tips of the ventral scales. The background color of the tail is as green as the body on its anterior half, with scales distinctly edged with black, producing a strongly reticulate pattern. There are 2–5 irregular black crossbars on each side of the tail which, becomes more or less abruptly greenish-orange, salmon, pinkish-red, or rusty-red on its posterior half.

The upper head surface and temporal regions are as green as the body, the sides of the head and temporals are slightly paler and usually more yellowish-green or paler green. The rostral is green with black vertical and horizontal streaks. Scales of the upper snout surface are also green, broadly edged with black, and may be entirely black with the exception of a large, round green blotch on each internasal and each scale behind the internasal. Supraoculars green, broadly edged with black; many scales of the cephalic and occipital regions black, producing a pattern of black blotches or streaks. On each side of the head, a long streak usually extends from internasals to the posterior part of the head along the inner edge of supraoculars; two oblique black streaks on the occiput forming an inverted V; its apex pointing forward. Supralabials greenish-yellow, pale green, yellowish-green, or bluish-green, paler than the upper head surface, strongly edged with black, black edges at the limits between third–fourth and fourth–fifth supralabials broader and more conspicuous; preoculars and postoculars green and black or entirely black; a black postocular streak extends from the eye to the corner of the mouth on the postoculars or lower postocular and the upper rows of temporals, more or less broadly blotched with the green background color. The chin and throat are white, cream, pale greenish-yellow, or yellowish-green, uniform or with scattered dark grey dots. The infralabials are white, pale bright yellowish-green, or pale green, with or without a few dark grey spots, edged with black on their posterior margin; gular scales below the corner of the mouth narrowly edged with black. In life, the eye is rather dark, bronze, brown, dark greyish-brown, or golden-brown.

The venter is yellowish-green, pale greenish-yellow, or pale green; each ventral is narrowly edged with black posteriorly, the edge usually broader on their central part tips of ventrals narrowly edged with dark grey or black, producing an irregular, zigzag-like dark ventral stripe below the pale ventrolateral stripe. The under surface of the tail is green or greenish-yellow on its anterior half, with subcaudal scales broadly edged with black producing a conspicuous reticulation, becoming more or less abruptly greenish-orange, salmon or pinkish-red, strongly reticulated with black.

Vogel et al.

Juveniles show a rather different pattern. The dorsum is usually bright or grass-green, with only faint and narrow black spots or edges of dorsal scales producing faint, diffuse crossbars. The head is speckled with black dots but without dark lines and streaks on the edges of scales; no black edges on the suture of supralabials but with scattered black spots. The orange, salmon color or rusty red color of the tail is brighter than in adults.

Distribution ( Fig. 8 )

Indonesia

Figures

Fig. 5. Comparative dorsal view of the head of Trimeresurus gunaleni spec. nov. (left) and T. sumatranus (right). Left from above: Male, female (holotype), male, all from Sumatra Utara Province, Sumatra alive, right adult female alive from Bengkulu Province, Sumatra, adult male alive from Bengkulu Province, Sumatra, preserved female from Borneo. Photos: N. Maury.

Fig. 6. Comparative lateral view of the head of Trimeresurus gunaleni spec. nov. (left) and T. sumatranus (right). Left from above: Male, female (holotype), male, all from Sumatra Utara Province, Sumatra alive, right adult female alive from Bengkulu Province, Sumatra, adult male alive from Bengkulu Province, Sumatra, preserved female from Borneo. Photos: N. Maury.

Fig. 7. Comparative ventral view of the head of Trimeresurus gunaleni spec. nov. (left) and T. sumatranus (right). Left from above: Male, female (holotype), male, all from Sumatra Utara Province, Sumatra alive, right adult female alive from Bengkulu Province, Sumatra, adult male alive from Bengkulu Province, Sumatra, preserved female from Borneo. Photos: N. Maury.

Fig. 8. Live female of Trimeresurus sumatranus from vincity of Padang Panjang, Sumatera Barat Province, Sumatra. Photo: G. Vogel.

Fig. 9. Live female of Trimeresurus sumatranus from Bengkulu Province, Sumatra. Photo: G. Vogel.