Parvoscincus abstrusus, Linkem, Charles W. & Brown, Rafe M., 2013

Linkem, Charles W. & Brown, Rafe M., 2013, Systematic revision of the Parvoscincus decipiens (Boulenger, 1894) complex of Philippine forest skinks (Squamata: Scincidae: Lygosominae) with descriptions of seven new species, Zootaxa 3700 (4), pp. 501-533 : 516-518

Parvoscincus abstrusus sp. nov.

Figs. 2 ; 3B, C; 4M, N, O, P, Q, R; 5I, J

Sphenomorphus decipiens: Brown & Alcala, 1980: 186 (part) Parvoscincus decipiens sp. 3: Linkem, Diesmos, Brown, 2011

Holotype. PNM 9783 (formerly KU 320071, A. C. Diesmos Field No. 4646); Male; Philippines, Luzon Island, Laguna Province, Municipality of Los Baños, Mt. Makiling, N: 14.150º, E: 121.231º, elevation 783 m above sea level. Collected 11 January, 2009 by CWL.

Paratypes. Same locality as holotype: KU 320063, KU 320065–7 KU 326590–1, KU 330743, KU 331678– 9 Females; KU 320068–70, KU 326588–9, KU 330744, KU 331676, KU 331680– 1 Males. Polillo Island, Quezon Province: KU 304073 Female. Luzon Island, Camarines Norte Province, Municipality of Labo, Barangay Tulay Na Lupa, Mt. Labo: KU 313861, KU 313864 Females; KU 313859, KU 313868–9, PMNH 2087 Males. Luzon Island, Camarines Sur Province, Municipality of Naga City, Barangay Panicuason, Mt. Isarog: TNHC 62884– 5 Females; TNHC 62883, TNHC 62886 Males. Luzon Island, Albay Province, Municipality of Tiwi, Barangay Banhaw, Mt. Malinao: TNHC 62887 Female; TNHC 62888 Male. Luzon Island, Albay Province, Municipality of Malinao, Barangay Tagoytoy, Mt. Malinao: TNHC 62896 Male; TNHC 62897– 8 Females.

Referred specimens. KU 320062, KU 320064, KU 331677, KU 331682, KU 313862, KU 313860, KU 313865, KU 313863, CAS 62320–34, CAS 61067–75, CAS 174212–3, CAS-SUR 24186–93.

Genetic Data. GenBank KF425377 – KF425394 .

Diagnosis. Parvoscincus abstrusus sp. nov. can be identified by the following combination of characters: (1) A small body size (SVL at maturity 32–45 mm); (2) MBSR = 33–38; (3) PVSR = 58–69; (4) dorsal scales nonstriated with weak apical pits or lacking apical pits; (5) apical pits on forelimbs and hind limbs; (6) four enlarged supraoculars; (7) anterior loreal divided laterally; (8) three preoculars; (9) and 15–19 Toe IV SDL.

Parvoscincus abstrusus sp. nov. is the sister species to P. decipiens sensu stricto, and closely related to P. agtorum sp. nov., P. jimmymcguirei sp. nov., and P. arvindiesmosi sp. nov. ( Fig. 2 ). Parvoscincus abstrusus sp. nov. can be distinguished from P. jimmymcguirei sp. nov. by lacking or only having weak apical pits on dorsal scales (vs. multiple rows of apical pits on dorsal scales); by having two anterior loreals (vs. one anterior loreal); having a black throat in males and white throat in females (vs. white throat with dark brown mottling); dorsolateral band thin and weakly differentiated from flank color (vs. dorsolateral band broad and bordered dorsally and ventrally by white flecks).

Parvoscincus abstrusus sp. nov. can be distinguished from P. arvindiesmosi sp. nov. by the presence of a divided anterior loreal (vs. a single anterior loreal); by the presence of weakly developed apic pits on the dorsal scales or lacking apical pits (vs. multiple rows of apical pits on dorsal scales); having a black throat in males and a white throat in females (vs. a white throat in males and a light brown streaked throat in females); having a weak dorsolateral band (vs. a broad dorsolateral band that extends onto the dorsum).

Parvoscincus abstrusus sp. nov. can be distinguished from P. decipiens by the presence of two anterior loreals (vs. one anterior loreal); males having black throats and females having white throats (vs. throats white with a few light brown flecks); usually having more MBSR (33–36 vs. 30–34).

Parvoscincus abstrusus sp. nov. can be distinguished from P. agtorum sp. nov. by the presence of two anterior loreals (vs. one anterior loreal); smaller body size (32.02–43.27 vs. 44.91 mm); fewer paravertebrals (<69 vs. 71); fewer midbody scale rows (33–36 vs. 39); dark throat in males and white throat in females; and a white line from the posterior of the eye to the forelimb (vs. a white line from posterior of eye to ear).

Description of holotype. A small-sized Parvoscincus , SVL 41.01 mm, with clawed, pentadactyl limbs. Snout rounded in lateral profile with lower jaw slightly sunk; rostral wide forming an oval dorsal margin with the nasals and frontonasal scale; frontonasal wider than long, in contact with nasals, rostral, anterior loreals, and prefrontal scales; prefrontals in broad medial contact, in contact with anterior and posterior loreals, frontal, frontonasal, 1st supraciliary, and 1st supraocular; frontal slightly longer than wide, in contact with two supraoculars, posterior apex rounded and wide; four enlarged supraoculars, 1st largest, 2nd widest; frontoparietals fused, in contact with three supraoculars; interparietal triangular with parietal eye in posterior third; parietals in broad overlap, left overlapping right, in contact with fourth supraocular, postsupraocular, primary and secondary temporal; nuchals same size as dorsals, not obliquely enlarged.

Nasal pierced in center by large naris, surrounded anteriorly by rostral, dorsally by frontonasal, posteriorly by two anterior loreals, and ventrally by 1st supralabial; two anterior loreals, anteriodorsal loreal twice as large as anterioventral loreal, posterior loreal wider than anterior, similar in size to anteriodorsal loreal; preoculars three; six supralabials, 4th widest and under center of eye; supraciliaries 11, anterior four and posterior two larger than rest of series; 16 ciliaries; lower eyelid scaly and transparent, lacking non-scaled “window;” suboculars 10, largest anteriorly; primary temporals three, secondary temporals two, lower overlapping upper; ear large (EarD [1.74]/ EyeD [2.64] = 0.659), round, and moderately sunk.

Infralabials seven, decreasing in size posteriorly in series; mental large, forming a straight suture with a single large postmental and first infralabials; postmental contacts anterior two infralabials; chin scales increasing in number posteriorly (one, three) and then blending into size and shape of gular scales; gular scales slightly smaller than ventrals.

Body slightly elongate (AGD [21.12]/SVL [41.01] = 0.51), cylindrical, with 38 equal-sized midbody scales, limbs overlapping when adpressed; lateral body scales with 2 or 3 rows of apical pits; paravertebral scales 64, imbricate, with 1 row of weak apical pits on some scales. Tail elongate, slightly longer than body (TL [51.87]/SVL [41.01] = 1.3) cylindrical at base, slightly thicker dorsally than ventrally; subcaudal scales nondifferentiated; tail original and complete.

Forelimbs smaller than hind limbs (FLL [3.80]/HLL [4.58] = 0.83), pentadactyl; dorsal forelimb scales slightly smaller than body scale, ventral forelimb scales much smaller than ventral scales, dorsal and ventral forelimb scales imbricate with multiple rows of apical pits; multiple rows of dorsal scales on digits. Relative digit length with lamellae (L/R) in parentheses IV(11/10)> III(10/10)> II(8/8)> V(8/8)> I(5/5). Palmar scales irregular, raised, forming ventral protrusions from palmar surface; large set of four scales on distolateral edge of Digit V to the wrist, largest scale at wrist.

Hind limbs small (HLL [4.58]/SVL [41.01] = 0.11), pentadactyl; dorsal and ventral hind limb scales smaller than body scales; dorsal scales with apical pits, ventral scales without apical pits; multiple scale rows on dorsal side of digits. Lamellae slightly keeled. Relative digit length with lamellae (L/R) in parentheses: IV(17/16)> III(11/11)> V(9/9)> II(8/8)> I(5/5). Plantar scales irregular, slightly raised; four large, ventrally pointed scales along ankle/ plantar margin; ventrally raised scales along distolateral edge of Digit V to ankle, increasing in size toward ankle.

Precloacal region with series of enlarged scales between pelvic region and cloaca, more elongate than ventral scales; medial precloacal scales larger, overlapping lateral scales.

Coloration of holotype. Dorsal ground color brown, dark brown vertebral spots going from the head to the tail. Head color black, throat black to gular region, ventrum white ( Fig. 4 M, N). Lateral head black with white spots, thin white line from the ventral portion of eye extending over the ear and stopping before the forelimb insertion. Dorsolateral band thin, restricted to the dorsal margin, intermittently broken by ground color. Flanks light brown. Forelimbs and hind limbs brown dorsally, white ventrally, posterior portion with large white spots on black. Coloration in life does not differ substantially from that in preservative (RMB photos).

Variation. Males have dark black heads and throats, females have white throats and light brown heads ( Fig. 4 M, N, O, P, Q, R). Throats on females occasionally with brown flecking and males with white spots on the black throat. White spots on males in life are bluish ( Fig. 3 B). Lateral division of the anterior loreal is variable within and between populations. Most samples have a divided loreal, but some have a single anterior loreal. Variation in meristic and mensural characters in the type series and referred specimens is presented in Table 2.

Distribution ( Fig. 1 ). The new species is known from 800 m above sea level on Mt. Isarog (Municipality of Naga City, Barangay Panicuason) 450–700 m above sea level on Mt. Malinao (Municipality of Tiwi, Barangay Banhaw; and Municipality of Malinao, Barangay Tagoytoy, Sitio Kumagingking) Polillo Is. (Municipality of Polillo, near Polillo town), Mt. Labo (Municipality of Labo, Barangay Tulay na Lupa) and Mt. Makiling (Municipality of Los Baños, Barangay Batong Malake).

Natural History. Found under logs and in leaf litter in secondary growth forest. Males and females are found in abundance on Mt. Makiling outside of the Los Baños College campus. Breeding males and females have been collected in January.

Etymology. The specific epithet is an adjectival formation of the Latin participle abstrusus , meaning hidden, or concealed.

Figures

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

FIGURE 2. Partitioned Bayesian majority rule consensus estimate of molecular phylogeny from the ND 2 data of Parvoscincus. Populations within the P. decipiens complex are genetically unique and are diagnosed as new species based on morphological differences. Black circles label nodes with posterior probabilities above 0.95.

FIGURE 3. Photographs in life of (A) P. jimmymcguirei sp. nov. (Female); (B) P. abstrusus sp. nov. (Male); (C) P. abstrusus sp. nov. (Female); (D) P. arvindiesmosi sp. nov. (Male); (E) P. banahaoensis sp. nov. (Female); (F) P. decipiens (Male)

FIGURE 4. Photographs of heads from ventral, lateral, and dorsal perspective to show color pattern variation among species. Images A, B, C Parvoscincus decipiens; D, E, F Parvoscincus jimmymcguirei sp. nov. holotype; G, H, I, Parvoscincus arvindiesmosi sp. nov. holotype; J, K, L Parvoscincus agtorum sp. nov. holotype; M, N, O, Parvoscincus abstrusus sp. nov. holotype (Male); P, Q, R, Parvoscincus abstrusus sp. nov. paratype (Female); S, T, U, Parvoscincus banahaoensis sp. nov. holotype; V, W, X, Parvoscincus palaliensis sp. nov. holotype; Y, Z, AA, Parvoscincus aurorus sp. nov. holotype.