Tropidolaemus wagleri ( Boie, 1827 )

Vogel, Gernot, David, Patrick, Lutz, Mario, Rooijen, Johan Van & Vidal, Nicolas, 2007, Revision of the Tropidolaemus wagleri-complex (Serpentes: Viperidae: Crotalinae). I. Definition of included taxa and redescription of Tropidolaemus wagleri (Boie, 1827), Zootaxa 1644 (1), pp. 1-40 : 18-23

Tropidolaemus wagleri ( Boie, 1827)

( Figs. 8–11 )

Diagnosis.— A species of the genus Tropidolaemus , characterized by (1) internasals always in contact; (2) a strong ontogenetic variation of the background body colour: black (never green) in adult females, whereas males and juveniles retain a vividly green background colour; (3) a strong ontogenetic variation of the pattern: yellow crossbands around the body in adult females, white spots in adult and juvenile males, white crossbars in juvenile females; (4) a black postocular stripe in adult females and a white and red one in males and juveniles of both sexes; (5) a banded belly in adult females and a uniform belly in males and juveniles; (6) 21–23 DSR at midbody in males and 23–27 in females, usually feebly keeled in males and distinctly keeled in females; (7) 143–152 VEN in males and 134–147 VEN in females; (8) 50–55 SC in males and 45–54 in females. Other characters appear in the Description below.

Description and variation.—The maximal total length among our sample is 920 mm (SVL 770 mm, TaL 150 mm) for a female from Thailand (MNHN 1996.0291). Our largest male is 522 mm long (SVL 435 mm, TaL 87 mm; BMNH 95.5.1.56; Natuna Islands).

Body laterally compressed, slender in males, thick and stout in females. Head strongly triangular, wide at its base, clearly distinct from the neck (at least twice as broad as the neck), average in length, amounting for 6.1–7.6% of SVL (x = 7.0 %) in males, 5.6–7.8% of SVL (x = 6.9 %) in females, wide at its base, a bit flattened in males, very thick in females when seen from the side. Snout obliquely truncated when seen from the side, with a distinct canthus rostralis, rather massive, rounded when seen from above, amounting for 25–30 % (x = 27 %) of HL in males and 21–30 % (x = 25 %) of HL in females, or 1.4–2.0 (x = 1.6) times as long as diameter of eye in males and 1.4–3.2 (x = 2.2) in females. Nostrils small, piercing in the middle of the nasal. Eye small, amounting for 0.6–1.6 (x = 1.0) times in males and 0.6–1.5 (x = 0.8) times in females of the distance eye–lip. Tail tapering progressively and prehensile.

Ratio TaL/TL: 0.139 –0.196, with a strong sexual dimorphism (see below).

This species exhibits quite an unusual ontogenetic variation in the ratio TaL/TL, a character that we had not observed in any species of the other pitvipers. If we consider males and females with a SVL below 250 mm and above 300 mm respectively, we obtain the values given in Table 4.

DSR: (21) 23-27 – 21-25 (27 in 1 specimen) – 17-21, weekly keeled or smooth in males, more or less strongly keeled in females.

VEN: 134–152 (plus 1–2 preventrals); SC: 45–55, all paired. Anal shield entire.

Rostral visible from above, about 1.2–1.3 times broader than high, triangular; nasals subrectangular, entire; 1 (rarely 2, in only 3/ 38 specimens) internasals, elongated, narrow, slightly bent, about 2 times as long as wide; internasals in contact in all examined specimens; on each side, 4-5 canthal scales, not or barely larger than adjacent snout scales, bordering the canthus rostralis; 1 elongate triangular loreal scale between upper preocular and the nasal; 2 elongate upper preoculars above the loreal pit; lower preocular forming the lower margin of loreal pit; 2 (rarely 3, in 2/76 occurrences)) postoculars; 1 (rarely 2, in only 2/76 occurrences) small, narrow, flat supraocular on each side, 2.0–3.2 (x = 2.4) times as long as wide, 0.4–0.7 (x = 0.6) times as wide as the internasals, irregularly bordered on their inner margins by the upper head scales; 5–9 (x = 6.8, s = 0.9) slightly enlarged scales on upper snout surface on a line between the scales separating the internasals and a line connecting the anterior margins of eyes, rhomboid, strongly keeled and imbricate; 12–17 (x = 13.8; s = 1.5) cephalic scales between the middle of the supraoculars, small, strongly keeled, flat and imbricate; occipital scales not larger than cephalic scales, strongly keeled; temporal scales small, irregular in size, in 3 rows, all strongly keeled; 1 or 2 small, thin, elongated, suboculars; 8–11 SL (x = 9.4; s = 0.5) on each side, total number 16–21 (x = 18.9; s = 1.1); 1 st SL rather short, entirely separated from nasal; 2 nd SL short, not bordering the anterior margin of the loreal pit, topped by a prefoveal scale which borders the pit and is separated from the nasal by 2–4 minute scales; 3 rd SL longest and usually highest, 1.2–1.9 (x = 1.65; s = 0.20) times as long as high, either in contact (20 / 76 occurrences) with the subocular(s), or usually separated by 1 (54 / 76 occurrences) or 2 (2/76) small scales(s), with a sexual dimorphism; 4 th SL nearly as long as high, 0.7–1.1 (x = 0.9; s = 0.1) times as high as 3 rd SL, either in contact (7 / 76 occurrences, all males) with the subocular(s), or separated by 1 (23 / 76 occurrences), 2 (45 / 76) or 3 (1 / 76) small scales(s); 10–13 IL (x = 11.4; s = 1.0) on each side, total number 20–28 (x = 23.1; s = 1.7), strongly keeled; scales of the 1 st pair longitudinally in contact, first four pairs in contact with anterior chin shields; 7–10 rows of strongly keeled gular scales.

In life and in preservative, this species shows both strong sexual and ontogenetic dimorphisms.

Adult females: they display the typical and complex “speckled” black and yellow coloration. Body deep glossy black, with 25-30 irregular bright yellow vertical crossbars, 2 or 3 scale wide, separated by 5-7 scales; many scales of the black areas with yellow or yellowish green centre, this colour becoming broader and more green on the lower side of the sides; tail also deep black, irregularly marked with very irregular bright yellow blotches, the first ones forming incomplete crossbands, the others reduced to elongated blotches; tip of tail entirely black.

The dorsal head surface is deep black with small irregular yellow blotches; a wide, bright yellow postocular streak, narrowly edged below with white, extending from eye to behind the corner of the mouth in widening posteriorly; lower half of rostral and supralabials ochre yellow, narrowly edged with black; area between the posterior supralabials and the postocular streak deep black, the lower half of this area speckled with pale yellowish green, the upper part more or less entirely black, producing a distinct black stripe bordering below the postocular streak.

Venter yellow, the posterior edge of ventrals black; chin and throat yellow, the infralabials narrowly edged with black giving dark crossbands; some greenish-yellow, black edged blotches on the chin near the posterior infralabials.

Adult and juvenile males: body bright or deep green, lateral a bit lighter, with small dorsolateral dots, anterior red, posterior white. These continue to the tail, tip of the tail mottled with brown. A loreal streak running from the nasal to the ankle of the mouth, ventrally red and dorsally white coloured. Belly and underside of the head light, uniform.

Juvenile females: as in males, but the white (cream or pink in life) and red rounded, dorsolateral, spots are replaced by vertical crossbars of the same colour, reaching about the limit of the upper third of the sides.

Sexual dimorphism.—It is clearly marked in the total length, in the ratio TaL/TL, the pattern, the keeling of the dorsal rows and in other several other characters as listed below. Several scale values are higher for females probably due to their larger size.

The most important characters are as follows:

(1) Difference in the ratio TaL/TL:

0.157 –0.196 (x = 0.183; s = 0.010) in males, vs. 0.139 –0.178 (x = 0.157; s = 0.011) in females.

(2) Differences in the mean number of ventrals:

143–152 (x = 146.9; s = 2.9) in males vs. 134-147 (x = 139.5; s = 3.2) in females.

(3) Differences in the number of number of scale-rows at midbody:

21–23 (x = 22.3; s = 1.0) in males vs. 23 – 27 (x = 24.9; s = 0.6) in females.

(4) Differences in the total number of SL:

16–18 (x = 16.7; s = 1.2) in males vs. 17–20 (x = 18.9; s = 1.1) in females.

(5) Differences in the number of cephalic scales:

12–13 (x = 12.7; s = 0.5) in males vs. 13–15 (x = 14.6; s = 1.3) in females.

(6) Differences in the total number of infralabials:

19 – 28 (x = 23.1; s = 1.7) in males vs. 17–20 (x = 20.7; s = 1.5) in females.

(7) Differences in the number of scales between 3rd SL and subocular in males:

0 in all in males vs. 0-2 (x = 0.9) in females.

(8) Scale-rows at midbody less strongly keeled in males than in females.

(9) Pattern: see above. Males generally show no ontogenetic shift in colouration, whereas the colouration in

females strongly varies. This is evident for the pattern, the postocular streak, the ground colour and the

ventral colour. For details, see Table 5.

Remarks.—only adult specimens are considered.

Range.— Vietnam. Known from the southern provinces of Minh Hai and Song Be ( Orlov et al., 2003) . — Thailand. Known only from the South: it has been recorded from the provinces of Phang Nga, Pattani, Surat Thani, Nakhon Si Tammarat , Narathiwat, and Yala ( Nabhitabhata et al., 2004) . — Federation of Malaysia. West Malaysia. Probably distributed throughout the Peninsula . — Singapore. — Indonesia. Recorded from the islands of Sumatra, Bangka, Mentawei Archipelago, Natuna Islands , Nias , and Riau Archipelago .

Materials (38 specimens). Indonesia. Natuna Islands . BMNH 95.5 .1.56, “Sirhassen, Natuna Islands”, now Serasan Island, Natuna Archipelago. — Riau Archipelago. ZMA 17718, “Doeriam”, now Durian Island, Province of Riau . — Sumatra . MHLCLFE 206-207 , vicinity of Lubuksao, between Lubukbasung and Mukomuko, on the northwestern shore of Lake Maninjau, Province of Sumatera Barat . - MNHN 1879.0708 , “Bedagneh River, Deli”, now Bedagai River, Province of Sumatera Utara ; MNHN 4063 , MNHN 7767 , MNHN 1880.0043 , MNHN 1998.0479 , “ Sumatra ” ; MNHN 1998.0480 , MNHN 1999.6577 - 6578 , Jambi Province ; MNHN 2000.4274 - 84 , Lake Maninjau, Province of Sumatera Barat . - ZIH No number (1)-(3), “ Sumatra ” . - ZMH R-07440, Padang District, Province of Sumatera Barat ; ZMH R-07448-450, Sungei Lalak (0°27'S, 102°59'E), Province of Indragiri . - Federation of Malaysia. West Malaysia . MNHN 1884.0160 - 0161 , “Malaya”; MNHN 2006.0422 , “ West Malaysia (from the pet trade) . — Thailand. MNHN 1990.4250 , MNHN 1990.4287 , MNHN 1996.0291 - 0292 , MNHN 2006.0417 - 0418 , “Thailand” (from the pet trade) .

Figures

FIGURE 8. Tropidolaemus wagleri. Living adult female from Jambi Province, Sumatra, Indonesia. Photograph by Gernot Vogel.

FIGURE 9. Tropidolaemus wagleri. Living adult female from Pahang, West-Malaysia. Photograph by Dick Visser.

FIGURE 10. Tropidolaemus wagleri. Living adult male from South Thailand. Photograph by Gernot Vogel.

FIGURE 11. Holotype of Trimesurus maculatus (BMNH 1.2.5a = BMNH 1946.1.17.69). Adult male, Singapore. General view. Photograph by Gernot Vogel.