Parvoscincus leucospilos ( Peters 1872 )

Siler, Cameron D., Linkem, Charles W., Cobb, Kerry, Watters, Jessa L., Cummings, Sean T., Diesmos, Arvin C. & Brown, Rafe M., 2014, Taxonomic revision of the semi-aquatic skink Parvoscincus leucospilos (Reptilia: Squamata: Scincidae), with description of three new species, Zootaxa 3847 (3), pp. 388-412 : 393-397

Parvoscincus leucospilos ( Peters 1872)

( Figs. 3–5 )

Lygosoma (Hinulia) leucospilos Peters, 1872:684 .

Sphenomorphus leucospilos Brown and Alcala, 1980:172 ; Bauer et al., 1995; Linkem et al., 2011; McLeod et al., 2011. Parvoscincus leucospilos Linkem, Diesmos & Brown, 2011 ; Linkem & Brown 2013 (part)

Type designation. Based on ICZN articles 74.1 and 74.7 and in accordance with recommendation 74D we designate ZMB 7467 as the lectotype of Parvoscincus leucospilos . Specimen CAS 64232 is designated a paralectotype.

Diagnosis. Parvoscincus leucospilos can be distinguished from congeners by the following combination of characters: (1) body size medium (SVL 42.6–54.4 mm); (2) Toe-IV lamellae 15–17; (3) supralabials six or seven; (4) infralabials 6–9; (5) midbody scale rows 30–34; (6) paravertebral scale rows 61–67; (7) prefrontals in medial contact; (8) prefrontals contact first supraocular; (9) frontoparietals fused; (10) head pigmentation heavily mottled; (11) upper arm pigmentation absent; (12) subcaudal pigmentation absent; (13) dorsal white spots large, welldefined; (14) dorsal white bands 9–13; (15) lateral body coloration bright reddish-orange; (16) tail dorsolaterally compressed; and (17) semi-aquatic (Tables 2, 3).

Comparisons. Characters distinguishing Parvoscincus leucospilos from all species of Parvoscincus are summarized in Tables 2 and 3. Parvoscincus leucospilos most closely resembles P. duwendorum , P. manananggalae , and P. tikbalangi . However, P. leucospilos differs from these three taxa by having head pigmentation heavily mottled (vs. moderately mottled; Figs. 4 , 5 ), and by the absence (vs. presence) of dark pigmentation on the upper arm surface. Parvoscincus leucospilos further differs from P. duwendorum and P. manananggalae by having prefrontals in medial contact (vs. separated); from P. duwendorum and P. tikbalangi by having dorsal white spots large and well-defined (vs. faint); from P. manananggalae and P. tikbalangi by the presence of bright reddish-orange lateral coloration (vs. absence of coloration [ P. manananggalae ], presence, reduced, tan [ P. tikbalangi ]); from P. duwendorum by having a greater number of Toe-IV lamellae (15–17 vs. 12), a greater number of paravertebral scale rows (61–67 vs. 60), a greater number of midbody scale rows (30–34 vs. 26), a tendency towards a greater number of longitudinal ventral scale rows (41–47 vs. 41), and fewer dorsal white bands (9–13 vs. 15); from P. manananggalae by the absence of subcaudal dark pigmentation (vs. presence); and from P. tikbalangi by having a tendency towards a greater number of paravertebral scale rows (61–67 vs. 58–63) and a tendency towards a greater number of midbody scale rows (30–34 vs. 28–32).

Redescription (based on examination of paralectotype, CAS 64232, and 10 recently collected specimens, Appendix 2). Details of the head scalation of an adult male (KU 313870) are shown in Figure 4 , and scientific illustrations of the dorsal and lateral views of the head of the paralectotype are shown in Figure 6. A medium sized Parvoscincus , SVL 42.6–54.4 mm, with clawed, pentadactyl limbs. Head distinct from next, with enlarged jaw adductor musculature in the temporal region. Snout pointed in dorsal aspect, rounded in lateral aspect; rostral wide forming a nearly perpendicular margin with frontonasal, slightly rounded margin with nasals; frontonasal wider than long, in contact with nasals, rostral, anterior loreal, and prefrontal scales; prefrontals in broad medial contact, in contact with anterior and posterior loreals, frontal, frontonasal, and first supraocular, and in some specimens, in point contact with first supraciliary; frontal greatly longer than wide, in contact with two supraoculars on right, two on left, rounded anteriorly, pointed posteriorly; four enlarged supraoculars, first largest; single, large frontoparietal, in contact with supraoculars II–IV or III and IV; interparietal arrowhead-shaped; parietals in moderate to broad medial contact, in contact with fourth supraocular, postsupraoculars, and primary and secondary temporals; primary temporals two, ventral largest, overlapping dorsal; secondary temporals two, large, dorsal largest, ventral overlapping dorsal; tertiary temporals two, dorsal largest, ventral overlapping dorsal; auricular opening large.

Nasal pierced in center by large naris, surrounded anteriorly by rostral, dorsally by frontonasal, posteriorly by anterior loreal, and ventrally by first supralabial; anterior loreal one, posterior loreal roughly equal in size; preoculars two; supralabials six or seven; lower eyelid scaly, semi-transparent, nonscaled “window” absent; ear large, moderately sunk.

Infralabials 6–9, decreasing in size posteriorly in series; mental small, forming straight suture with single, large postmental and first infralabials; enlarged chin shields in three pairs; gular scales slightly smaller than ventrals.

Body elongate, cylindrical, slender, with 30–34 equal sized midbody scales, limbs overlapping when adpressed; paravertebral scales 61–67, imbricate, smooth, without striations, keels or pits. Tail elongate, dorsolaterally compressed, longer than body (TL/SVL 0.99–1.57 [1.26 ± 0.18]); subcaudal scales similar to lateral scales for basal half of tail, enlarged for distal half of original tail. Precloacal region with series of enlarged scales between pelvic region and cloaca, more elongate than ventral scales; medial precloacal scales larger.

Forelimbs smaller than hind limbs, pentadactyl; forelimb scales slightly smaller in size than body scales, imbricate and smooth, reducing slightly in size closer to manus; lamellae becoming slightly keeled distally on each digit; relative digit length I <V <II <III = IV; palmar scales irregular, raised, forming ventral protrusions from palmar surface. Hind limbs small, pentadactyl; hind limb scales equal in size and shape to body scales; dorsal scales on digits multiple. Lamellae keeled proximally and distally, flat for a few scales in between on Toe IV; Toe IV lamellae 15–17; relative digit length I <II <V <III <IV; plantar scales irregular, slightly raised.

Coloration in preservative ( Figs. 3 , 4 ). The dorsal background color is medium brown, with pronounced mottling of various shades of brown. Three longitudinal rows of cream spots, ringed with darker brown, start just behind the head and run the length of the body with faint light brown longitudinal stripes between. Spotting and striping fade into a solid medium brown color approximately halfway down the tail. On the lateral surface of the body, spots merge to become indistinct perpendicular cream stripes, with mottled medium brown between. This pattern fades indistinctly into the solid cream present on the ventral surface. The distinctive forelimb spot is pronounced and continues nearly to the first joint. Otherwise, the mottled pattern present on the dorsal surface of the body continues down the dorsal surface of the fore- and hind limbs. The ventral surface of the limbs is a solid cream, with the exception of very faint light brown mottling present on the hands and feet. The solid ventral cream color of the body extends to about halfway down the length of the tail, then transitions to thin medium brown perpendicular stripes. The stripes become increasingly close together as they approach the tail tip, which is a solid medium brown. The dorsal surface of the head is mottled the same as the dorsal surface of the body, with various shades of brown. Three small cream spots are arranged in a triangle on the head just posterior to the eyes. A series of distinct cream spots are visible on the labial scales, one row on the supralabial series and one on the infralabial series. A slightly lighter brown mottling occurs just below the eye and is present between the spots. The ventral surface of the head and body are solid cream in color.

Coloration in life (Differences from preserved specimens; Fig. 5 ). On the lateral surfaces of the body, the dark brown, mottled ground coloration is replaced with a vivid reddish-orange ground color, with randomly distributed small cream spots. The non-mottled patch on the upper forelimb proximate to the body is also a solid reddishorange color. The cream and brown mottling on the lateral surface of the head and the body anterior to the forelimb insertion is replaced by a pale blue and brown mottled pattern.

Measurements and scale counts of paralectotype in mm. SVL 44.2; AGD 23.2; TotL 101.0; TL 56.8; HL 6.1; HW 5.4; SnFa 16.5; ED 2.2; SNL 3.7; IND 1.0; FLL 4.3; HLL 6.2; MBSR 31; PVSR 63; ToeIVlam 17; SL 7; IFL 7; SO 4.

Distribution, ecology and natural history. Parvoscincus leucospilos is known from south-central and southeastern Luzon Island ( Fig. 1 ). No mention of the specific locality or province on Luzon Island was given for the types ( Peters, 1872). Although we are certain of our identification of P. leucospilos , we are unable to pinpoint the type locality on the basis of available specimens. Specimens are from Mt. Labo, Camarines Norte Province (KU313870), Mt. Palali, Barangay Maddiangat, Municipality of Quezon, Nueva Vizcaya Province (KU 325806–13), Barangay Kabayunan, Municipality of Dona Remedios Trinidad, Bulucan Province (KU 329388–92) and Mt. Banahao, Municipality of Tayabas, Quezon Province (TNHC 62682). The known elevational range of this species is 200–800 meters above sea level, based on Brown et al. (2013b).

Parvoscincus leucospilos occurs in primary- and secondary-growth forest habitats in riparian microhabitats; this semi-aquatic species frequently dives into cold, rapidly running water of montane streams when disturbed. The species is primarily found active during the day and has also been found sleeping on the edge of running water in forest debris at night. Parvoscincus leucospilos can be found in sympatry with Parvoscincus abstrusus , P. arvindiesmosi , P. beyeri , P. jimmymcguirei , P. laterimaculatus , and P. st eerei.

We have evaluated this species against the IUCN criteria for classification, and find that it does not qualify for Critically Endangered, Endangered, Vulnerable, or Near Threatened status. Parvoscincus leucospilos is quite abundant at sampled localities provided that some vegetation cover borders the streams where it has been collected and observed. We therefore classify this species as Least Concern LC (IUCN, 2010).

Etymology. The specific epithet “ leucospilos ” apparently refers to the distinctive coloration of this species, consisiting of prominent rows of white (from the Latin adjective “ leucos ”) spots (Latin, noun, “ spilos ”) down the dorsal surfaces of the body.

Figures

FIGURE 1. Map of the Luzon Island, Philippines, showing the collection localities for the new species and P. leucospilos.

FIGURE 3. Dorsal views of representative specimen heads and flanks, exhibiting pigmentation pattern variation among species.

FIGURE 4. Photographs of heads from dorsal and lateral perspectives to show pigmentation and scale pattern variation among species. With the exception of P. leucospilos (KU 313870), all photographs are of the holotypes of the new species.

FIGURE 5. Photographs in life of (A) P. leucospilos (Mt. Banahao; TNHC 62683); (B) P. leucospilos (Angat Watershed; KU 329388); (C) P. manananggalae sp. nov. (PNM 9794); and (D) P. tikbalangi sp. nov. (Holotype; PNM 9795).