Subdoluseps malayana, Grismer & Dzukafly & Muin & Quah & Karin & Anuar & Freitas, 2019

Grismer, L. Lee, Dzukafly, Zaharil, Muin, Mohd Abdul, Quah, Evan S. H., Karin, Benjamin R., Anuar, Shahrul & Freitas, Elyse S., 2019, A new skink of the genus Subdoluseps (Hardwicke & Gray, 1828) from Peninsular Malaysia, Zootaxa 4609 (2), pp. 358-372 : 363-369

Subdoluseps malayana sp. nov.

Suggested common name: Malaysian Supple Skink

Fig. 2

Lygosoma herberti (part) Sworder, 1933:103; Grismer, 2011:619; Karin et al.., 2018:361.

Subdoluseps herberti (part) Freitas et al., 2019:22.

Holotype. Adult male LSUHC 10995 collected by Zaharil Dzulkafly on 13 September 2012 from Teluk Rubiah , Perak, Peninsular Malaysia (36.86694°N 10.466944°E WGS 84; 19 m in elevation).

Paratypes. Adult female ZRC 2.158 collected by G. Hope Sworder on 21 March 1929 from “Kampung Menora, Perak near Kuala Kangsar”, (as the specimen tag reads), Peninsular Malaysia (4.715275°N 100.944263°E; 40 m in elevation) . Juvenile LSUHC 12098 collected by Mohd. A. Muin on 21 January 2013 from Bukit Panchor , Penang, Peninsular Malaysia (5.153889°N 100.54639°E; 79 m in elevation)

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Diagnosis. We consider Subdoluseps malayana sp. nov. to be a member of the genus Subduloseps in that it bears the suite of morphological characters that define the genus ( Freitas et al. 2019). Subdoluseps malayana sp. nov. can be differentiated from all other Subdoluseps by having the combination of an adult SVL of 62.2–65.4 mm; six supralabials with the fourth being elongate; six infralabials; four supraoculars; frontoparietal contacting three supraoculars on each side; no postinterparietal; eight or nine superciliaries; 7–9 suboculars not separated by supra- labials; prefrontals not in contact; one primary, two secondary, and three tertiary temporals, respectively; five or six nuchal scales; no deep postnasal groove; scaly lower eyelid lacking a window; two loreals; 29 or 30 transverse midbody scale rows bearing 3–5 keels; 57–64 paravertebral scale rows; 58–62 ventral scale rows; 19–21 caudal scale rows at the tenth subcaudal scale; seven or eight precloacal scales; smooth to weakly keeled subdigital finger lamellae; keeled to strongly keeled subdigital toe lamellae; 13–15 subdigital lamellae on fourth toe; and a brightyellow gular region, throat, and venter in adults. These characters are scored across S. herberti and S. samajaya in Table 4 .

Description of holotype. Adult male, SVL 62.2 mm; tail length 13.6 mm (broken); axilla-groin length 34.3 mm; head length 12.0 mm; rostral wider than long, in broad contact with supranasals; supranasals in contact medially and with frontonasal posteriorly; frontonasal wider than long; prefrontals relatively small, widely separated on midline; frontal elongate, widest anteriorly, in contact with first two supraoculars; four supraoculars; one small postsupraocular; frontoparietals in midline contact posterior to frontal, contacting second, third, and fourth supraoculars anterolaterally and parietals and interparietal posteriorly; right frontoparietal overlaps left frontoparietal; interparietal diamond-shaped, large, slightly projecting posteriorly, eyespot in posterior projection; postinterparietal absent; parietals large, in medial contact posterior to interparietal, contacting fourth supraocular and postsupraocular anteriorly; one primary temporal; two secondary temporals; three tertiary temporals; six nuchal scales between upper secondary temporals; nasals small, widely separated, trapezoidal, contacting rostral anteriorly, supranasal dorsally, anterior loreal posteriorly, first supralabial ventrally; nostril in center of nasal; anterior loreal taller than wide; posterior loreal wider than tall; upper and lower preoculars present; eight suboculars not interrupted by supralabials; eight superciliaries, posterior superciliary elongate and projecting dorsomedially, bordered medially by postsupraocular, posteriorly by postocular; six supralabials, fourth and fifth below eye; fourth supralabial elongate, in broad contact with eye; two postsupralabials; lower eyelid transparent, scaly, no enlarged central window; mental twice as wide as long; single, large postmental contacting first and second infralabials; three enlarged pairs of chinshields posterior to postmental, anterior pair contacting medially, contacting second and third infralabials; posterior pairs of chinshields separated medially, contacting infralabials; six infralabials; external ear opening small, oval, approximately one-half diameter as eyeball, bearing no anterior lobules; and tympanum deep.

Body elongate (AXG/SVL = 0.55); dorsal scales, cycloid, imbricate, bearing 3–5 keels; ventral scales smooth, same size as dorsal scales; 29 scale rows around midbody; 57 paravertebral scale rows; 58 ventral scale rows; eight enlarged precloacal scales; limbs, robust, short (FL/SVL = 0.07; HDL/SVL = 0.10), widely separated when adpressed; scales of dorsal surfaces slightly wider than those of ventral surfaces; palmar scales raised; plantar scales large, raised, subtuberculate; all digits short, scales of dorsal surfaces in a single row; subdigital lamellae on fingers smooth to weakly keeled; 15R,L keeled subdigital lamellae on fourth toe.

Coloration in life ( Fig. 2 ). Top of head, body, limbs, and tail brown; faint, diffuse, light, postorbital stripe extending to midway down body; supralabials, infralabials, gular region, throat, underside of limbs, and belly yellow.

Variation. Juveniles (LSUHC 12098 and LSUDPC 6940) differ substantially from the adult holotype in having a dark-brown to black head and nape transitioning into a dark copper-colored to dark-brown dorsum that transitions into a red-orange tail. The dull-yellow postorbital stripe is far more pronounced and better defined and extends past the midline of the body. The postorbital region to the forelimb insertion is nearly black. The venter is beige. Both paratypes have original tails that are thick and round in cross-section and the subcaudals are same size as the dorsal caudals.

Etymology. The name malayana is in reference to this species being endemic to Peninsular Malaysia.

Distribution ( Fig. 1 ). Subdoluseps malayana sp. nov. is known only from Peninsular Malaysia from the states of Penang and Perak but is expected to occur farther to the south.

Natural history. Subdoluseps malayana sp. nov. is a secretive, semifossorial species that presumably spends the majority of its time foraging within leaf-litter as no specimens to our knowledge have ever been seen on the surface. The Bukit Panchor specimen (LSUHC 12098) was collected in a pitfall trap in a lowland swamp forest ( Fig. 5 ). The Teluk Rubiah specimen (LSUHC 10995) was collected in coastal forest ( Fig. 5 ) after the leaf-litter had been scraped off the ground by a tractor. No natural history data were reported for the Kampung Menora specimen (ZRC 1.158), however, Kampung Menora is located in lowland dipterocaprp forest adjacent to the Slim River ( Fig. 5 ).

Comparisons. Subdoluseps malayana sp. nov. is most closely related to S. samajaya but differs from it by having a statistically significant higher mean number of precloacal scales (7.3 versus 4.0), three versus four tertiary temporal scales, and the fourth as opposed to the fifth supralabial scale being elongate. Subdoluseps malayana sp. nov. differs from S. herberti by having a statistically significant higher mean number of paravertebral scales (61.0 versus 56.6) and ventral scales (61.0 versus 56.3) and by having a yellow versus a beige venter. Subdoluseps malayana sp. nov. differs from other Southeast Asia species such as Lygosoma angeli (Smith) ; L. anguinum (Theobald) ; L. bampfyldei Bartlett ; S. bowringii (Günther) (usually); L. corpulentum Smith ; L. boehmei Ziegler, Schmitz, Heidrich, Vu & Nguyen ; S. frontoparietale (Taylor) ; L. haroldyoungi (Taylor) ; L. isodactylum (Günther) ; L. kinabatanganensis Grismer, Quah, Dzulkafly & Yambun ; L. koratense Smith ; L. peninsulare Grismer, Quah, Dzulkafly & Yambun ; L. quadrupes (Linnaeus) ; L. schneideri Werner ; L. tabonorum Heitz, Diesmos, Freitas, Ellsworth & Grismer ; and L. veunsaiensis Geissler, Hartmann & Neang (usually); Riopa lineolata (Stolizcka) ; R. popae (Shreve) ; S. siamanensis (Siler, Heitz, Davis, Freitas, Aowphol, Termprayoon & Grismer) by having keeled as opposed to smooth scales. Subdoluseps malayana sp. nov. differs from L. opisthorhodum Werner by being larger (62.2–65.4 mm SVL versus 45 mm) and having a faint, light-colored dorsolateral stripe as opposed to a wide, well-defined, black dorsolateral stripe.

Figures

FIGURE 1. Distribution of the species of the Suboluceps herberti group. Branch lengths in the inset do not represent genetic distance.

FIGURE 2. A. Subdoluseps malayana sp. nov. (holotype LSUHC 10995) from Teluk Rubiah, Perak, Peninsular Malaysia (photo by L. L. Grismer). B. Subdoluseps herberti (LSUDPC 4851) from Phuket Island, Phuket, Thailand (photo by W. Grossmann). C. Subdoluseps malayana sp. nov. (LSUDPC 10945) from Kampung Pisang, Perak, Peninsular Malaysia (photo by Z. Dzukafly). D. Subdoluseps herberti (LSUHC 11803) from Perlis State Park, Perlis, Peninsular Malaysia (photo by E.S.H. Quah). E. Subdoluseps samajaya from the Sama Jaya Forest Reserve, Kuching, Sarawak, East Malaysia (photo from Karin et al. 2018). F. Juvenile S. malayana sp. nov. (paratype LSUHC 12098) from Bukit Panchor State Park, Penang, Peninsular Malaysia (photo by M. A. Muin).

FIGURE 5. Forest habitat of Subdoluseps malayana sp. nov. A. Bukit Panchor State Park, Penang, Peninsular Malaysia (photo by M. A. Muin). B. Teluk Rubiah, Perak, Peninsular Malaysia (photo by Z. Dzukafly). C. Kampung Menora along the Slim River, Perak, Peninsular Malaysia (photo by L. L. Grismer).