Macrocalamus chanardi, CHANARDI DAVID & PAUWELS, 2004

Quah, Evan S H, Anuar, Shahrul, Grismer, Lee L, Wood, Perry L & Mohd Nor, Siti Azizah, 2020, Systematics and natural history of mountain reed snakes (genus Macrocalamus; Calamariinae), Zoological Journal of the Linnean Society 188 (4), pp. 1236-1236 : 1236-

MACROCALAMUS CHANARDI DAVID & PAUWELS, 2004

CHANARD’ S REED SNAKE

( FIGS 12–15 )

Macrocalamus chanardi David & Pauwels, 2004: 635–645 .

Macrocalamus lateralis (non Günther, 1864) Boulenger, 1894: 327, 1912: 153; Flower, 1899: 673; Smith, 1930: 57 (in part); Smedley, 1931a: 118 (in part), 1931b: 50; Tweedie, 1953: 53 (in part), 1957: 55 (in part), 1983: 60 (in part); Lim, 1963: 100 (in part), 1967: 122, 124 (in part); Grandison, 1972: 90 (in part), 1978: 289; Welch, 1988: 75 (in part); Manthey & Grossmann, 1997: 365 (in part), 366, fig. 273; Chan-ard et al., 1999: 34 (in part), 173, 2002: 57, pl. 17; Vogel & David, 1999: 315; Lim et al., 2002: 54; Leong & Lim, 2003: 133; Norhayati et al., 2011: 13.

Macrocalamus chanardi Das, 2010: 284 ; Grismer et al., 2010: 155.

Holotype: BMNH 1900.6.14.17. Type locality: ‘ Larut Hills , Perak, 3500–4500 ft. ’, now Bukit Larut, Perak, West Malaysia.

Diagnosis: Adult males reach 190 mm SVL, 221 mm TL, and adult females reach 237 mm SVL, 264 mm TL. Head triangular, tapered anteriorly when viewed dorsally, depressed anteriorly, indistinct from neck; snout rounded, elongate; body cylindrical, moderately elongate; tail short, tapered to a point; rostral higher than broad, triangular; separates nasals, touching prefrontals; nostril piercing the anterior lower margin of the nasal, adjacent to the upper margin of the first supralabial and to edge of rostral; internasals absent, fused with prefrontals; one pair of prefrontals; one elongate loreal; one preocular; one postocular; one supraocular; suboculars absent; 1 + 2 temporals; eight supralabials, first and second in contact with nasal, second, third and fourth in contact with the loreal, fourth and fifth entering orbit, seventh the largest; seven infralabials, first pair in contact, first to fourth in contact with anterior chin shield, sixth the largest; 15 dorsal scale rows at midbody; dorsal scales smooth; 104–127 ventral scales (males 104–114, females 114–127); cloacal scale single; 18–28 divided subcaudals (males 23–28, females 18–24) ( David & Pauwels, 2004; present study).

Coloration in life: The dorsal colour ranges from chestnut brown to dark brown or dark greyish brown. Along the flanks of the dorsum is a discontinuous row of lighter, dark-edged, elongated ocelli that extend the length of the body on the fifth and sixth or the sixth dorsal scale row. The colour of these ocelli is tan or orange–brown, and they are usually more prominent on the anterior portion of the body and fade posteriorly, especially in larger specimens. The head is usually the same colour as the body or slightly darker, and the supralabials are irregularly mottled with beige. The chin and infralabials are irregularly stippled with dark brown spots. A pale, cream or yellowish brown oblique streak extends from the parietals to the throat. In some specimens, the oblique streak is broad and merges posteriorly on the nape, giving rise to a poorly defined, lighter band. On the neck and the anterior part of the body there are two to six oblique, parallel, light orange or tan streaks. A single dark ventrolateral stripe formed by the dark brown tips of the ventral scales extends the length of the body and is bordered above by a narrow, lighter, pale orange or cream stripe formed by the colour of the first dorsal scale row. The colour of the venter ranges from vivid orange to pink or light coral and is usually lighter anteriorly and more vivid posteriorly. The throat and neck area are usually white or cream and gradually turn orange or pink towards the middle of the body. Sometimes there are dark spots scattered on the venter. In some specimens, a median dark brown, zig-zag subcaudal stripe is present. The juvenile coloration is similar to that of the adults, except for being more vividly coloured, and the row of lateral ocelli on the body are especially prominent ( David & Pauwels, 2004; present study).

Distribution: This species was considered to be widely distributed by David & Pauwels (2004) and listed as being from Bukit Larut, Cameron Highlands and Fraser’s Hill. In the present study, a new population was discovered at Gunung Jerai, Kedah that is conspecific with the Bukit Larut population ( Fig. 2 ). The molecular analyses reveal that the populations from the Cameron Highlands, Fraser’s Hill and the Genting Highlands may not be conspecific with the Bukit Larut and Gunung Jerai populations ( Fig. 1 ).

Natural history: Similar to other species of Macrocalamus , this is a semifossorial species that seeks refuge beneath surface debris, logs and rocks or in loose soil. Specimens have been collected by digging during the day and night but are considered diurnal by David & Pauwels (2004). In the present study, their observations are corroborated by observations of snakes crossing forest trails or roads during the early morning, where many are killed by traffic. David & Pauwels (2004) record this species from 1100–1500 m in elevation in wet montane forest, but we have collected specimens from as low as ~ 800 m a.s.l. in the Genting Highlands. The diet consists of earthworms, slugs, insects and their larvae ( David & Pauwels, 2004), and these observations are corroborated by E.S.H.Q. from a specimen from the Cameron Highlands ( LSUHC 11685) that regurgitated an earthworm. Vogel & David (1999) reported that captive specimens consumed crickets. This species has been observed in the diet of Calliophis intestinalis (Laurenti, 1768) at Fraser’s Hill, Pahang, when a DOR Calliophis intestinalis was observed with a half-swallowed M. chanardi hanging from its mouth (Rupert G. Lewis, personal observation). In addition, death-feigning behaviour has been noted in specimens from the Cameron Highlands ( Vogel & Hans, 2010). An adult female ( USMHC 1540) collected in late September was gravid and with two eggs.

Relationships: Macrocalamaus chanardi s.l. is a poorly supported monophyletic group composed of populations from Bukit Larut, Gunung Jerai, Cameron Highlands, Fraser’s Hill and Genting Highlands, albeit with weak support. This indicates that their distribution might represent a rapid radiation with subsequent incomplete lineage sorting. There is an uncorrected pairwise sequence divergence of 10.0% between the Banjaran Titiwangsa populations at Cameron Highlands, Fraser’s Hill and Genting Highlands and the Bukit Larut population. There is sequence divergence of only 1.0% between the populations from Gunung Jerai and Bukit Larut (Table 3). The sequence divergence among the Banjaran Titiwangsa populations is notable at 7.0%. Given that the sequence divergence between these morphologically undiagnosable populations is much higher than that of the morphologically diagnosable ( Table 6) species M. gentingensis and M. schulzi at 2.0%, this indicates that Macrocalamus cf. chanardi 1 and M. cf. chanardi 2 should be recognized as candidate species. Comparisons of morphological characters from the literature and recently collected material reveal a broad overlap in character states among specimens from the different populations and lineages, indicating that M. chanardi is a species in need of reappraisal. Further examination

*Data obtained from David & Pauwels (2004).

will follow the acquisition of additional material. A non-paramatric analysis with the Kruskal– Wallis H -test shows that the means of all the characters are significantly different (P ≤ 0.05) between males and females. However, there is no statistical support for significant differences of these variables among populations or the flagged candidate species ( Table 6), possibly owing to low samples sizes.

Material examined: Peninsular Malaysia, Perak, Bukit Larut USMHC 1616, LSUHC 8367, 8999–9001, 9737, 9848 and 12109, Pahang, Cameron Highlands LSUHC 9821, 11685, 12602, 12610 and 12614, USMHC 1960 and 1961, Pahang, Fraser’s Hill USMHC 1523 and 1540, Pahang, Genting Highlands USMHC 1687, Kedah, Gunung Jerai LSUHC 12572 and 12573.

Figures

Figure 1. Maximum likelihood phylogram of the genus Macrocalamus based on the Cytb gene, with Bayesian posterior probabilities and maximum likelihood bootstrap values, respectively.

Figure 2. Distribution of Collorhabdium williamsoni and Macrocalamus species in the Malay Peninsula. The tree was extracted from the maximum likelihood phylogram in Figure 1. Branch lengths do not represent genetic distance.

Figure 12. Top and bottom: dorsum and venter of Macrocalamus chanardi (LSUHC 12109) from Bukit Larut, Perak. Photographs by Evan Quah.

Figure 13. Top and middle: dorsum and venter of adult female Macrocalamus chanardi (LSUHC 12572) from Gunung Jerai, Kedah. Lower left and right: dorsum and venter of adult male M. chanardi (LSUHC 12573) from Gunung Jerai, Kedah. Photographs by Evan Quah.

Figure 14. Macrocalamus cf. chanardi 1 from Cameron Highlands, Pahang. Top and upper middle: dorsum and venter of female (LSUHC 11685) from Robinson's Falls. Lower middle left and right: dorsum and venter of male (USMHC 1960) from Habu. Bottom left and right: dorsum and venter of male (USMHC 1961) from Tanah Rata. Photographs by Evan Quah.

Figure 15. Macrocalamus cf. chanardi 2. Top and upper middle: dorsum and venter of adult female (USMHC 1540) from Fraser's Hill, Pahang. Lower middle left and right: dorsum and venter of juvenile (USMHC 1523) from Fraser's Hill, Pahang. Bottom left and right: dorsum and venter of juvenile (USMHC 1687) from Genting Highlands, Pahang. Photographs by Evan Quah.