Pseudogekko brevipes ( Boettger, 1897 )

Davis, Drew R., Watters, Jessa L., Köhler, Gunther, Whitsett, Collin, Huron, Nicholas A., Brown, Rafe M., Diesmos, Arvin C. & Siler, Cameron D., 2015, Redescription of the rare Philippine false gecko Pseudogekko brevipes (Reptilia: Squamata: Gekkonidae) and description of a new species, Zootaxa 4020 (2), pp. 357-374 : 359-363

Pseudogekko brevipes ( Boettger, 1897)

( Figs. 1–3 )

Lepidodactylus brevipes Boettger, 1897:161 , holotype male (Senckenberg Research Institute and Natural History Museum [SMF] 8988) from "Samar Island"; Taylor, 1922:74; Brown, 1964:6; Wermuth, 1965:97; Kluge, 1967:29; Kluge, 1968:332.

Pseudogekko brevipes (Boettger) : Kluge, 1968:332; Brown & Alcala, 1978:118; Kluge, 1993:30; Rösler, 2000:106; Gaulke et al., 2003:111; Siler et al., 2014c.

Diagnosis. Pseudogekko brevipes can be distinguished from congeners by the following combination of characters: (1) body size moderate (SVL 34.5–42.4 mm); (2) axilla–groin distance moderate (17.8–29.8 mm); (3) head length moderate (6.2–9.5 mm); (4) snout length long (3.8–4.4 mm); (5) Toe-IV scansors 15; (6) paravertebrals 211–218; (7) ventrals 96–117; (8) supralabials 13 or 14; (9) infralabials 14 or 15; (10) circumorbitals 33–35; (11) precloacal pores 12; (12) femoral pores absent; (13) conspicuous dorsolateral spotting present; (14) limb spotting absent; (15) tail banding absent; (16) body striping absent; (17) interorbital banding present ( Tables 1 , 2 ; Figs. 2 , 3 ).

Comparisons. Characters distinguishing Pseudogekko brevipes from all other species of Pseudogekko are summarized in Tables 1–3 . Pseudogekko brevipes most closely resembles the new species described below; however, it differs from this species by having a shorter snout–vent length in both males (39.0 mm vs. 41.1–52.5) and females (34.5–42.4 mm vs. 44.8–48.7), shorter eye–nares distance (3.0– 3.4 mm vs. 3.5–4.5), a tendency towards having both a shorter snout length (3.8–4.4 mm vs. 4.3–5.8) and internares distance (1.2–1.6 mm vs. 1.5– 1.9), fewer supralabials (13 or 14 vs. 15–17), circumorbitals (33–35 vs. 35–38), paravertebrals (211–218 vs. 226– 240), ventrals (96–117 vs. 119–129), and precloacal pores (12 vs. 13–15; Fig. 3 ).

Pseudogekko brevipes can be distinguished from P. chavacano by having a shorter snout–vent length (34.5– 42.4 mm vs. 54.7, 55.9), total length (72.0– 87.5 mm vs. 95.8), midbody width (4.5–5.8 mm vs. 6.4, 6.7), head length (6.2–9.5 mm vs. 10.4), head width (5.6–6.5 mm vs. 7.8, 8.5), and snout length (3.8–4.4 vs. 5.8, 6.0), fewer Finger-III scansors (12 vs. 15, 16), Toe-IV scansors (15 vs. 17–20), supralabials (13, 14 vs. 15, 16), infralabials (14, 15 vs. 16, 17), circumorbitals (33–35 vs. 46), ventrals (96–117 vs. 122, 123), and precloacal pores (12 vs. 16), greater number of paravertebrals (211–218 vs. 195–197), absence (vs. presence) of limb spotting and tail banding, and presence (vs. absence) of interorbital banding; from P. compresicorpus by having a shorter snout–vent length (34.5–42.4 mm vs. 54.9–59.7), total length (72.0– 87.5 mm vs. 105.9–117.3), head width (5.6–6.5 mm vs. 7.5– 10.1), and snout length (3.8–4.4 mm vs. 5.3–7.4), fewer Finger-III scansors (12 vs. 15–17), Toe-IV scansors (15 vs. 18 or 19), supralabials (13 or 14 vs. 16–20), circumorbitals (33–35 vs. 39–45), and ventrals (96–117 vs. 127–130), absence (vs. presence) of limb spotting, and presence (vs. absence) of interorbital banding; from P. d i t oy by having a shorter snout–vent length (34.5–42.4 mm vs. 49.4–52.6), midbody width (4.5–5.8 mm vs. 6.3–7.3), head width (5.6–6.5 mm vs. 7.7–7.9), and snout length (3.8–4.4 mm vs. 5.4–5.7), fewer Finger-III scansors (12 vs. 14 or 15), Toe-IV scansors (15 vs. 16 or 17), supralabials (13 or 14 vs. 17–20), infralabials (14 or 15 vs. 16 or 17), circumorbitals (33–35 vs. 40–43), and precloacal pores (12 vs. 18), greater number of paravertebrals (211–218 vs. 180–185), presence (vs. absence) of dorsolateral spotting and interorbital banding; from P. pungkaypinit by having a shorter snout–vent length (34.5–42.4 mm vs. 66.6–76.8), axilla–groin distance (17.8–29.8 mm vs. 37.2–41.2), total length (72.0– 87.5 mm vs. 125.3–141.2), midbody width (4.5–5.8 mm vs. 7.7–9.1), head length (6.2–9.5 mm vs. 11.4–13.6), head width (5.6–6.5 mm vs. 9.3–11.2), and snout length (3.8–4.4 mm vs. 6.7–7.5), fewer Finger-III scansors (12 vs. 15–17), Toe-IV scansors (15 vs. 17–21), supralabials (13 or 14 vs. 16–20), infralabials (14 or 15 vs. 17–19), circumorbitals (33–35 vs. 50–55), paravertebrals (211–218 vs. 265–280), ventrals (96–117 vs. 125– 155), and precloacal pores (12 vs. 17–20), presence (vs. absence) of dorsolateral spotting and interorbital banding, and absence (vs. presence) of body striping; from P. smaragdinus by having a shorter snout–vent length (34.5–42.4 mm vs. 50.2–64.3), total length (72.0– 87.5 mm vs. 103.6–129.7), midbody width (4.5–5.8 mm vs. 6.2–10.4), head width (5.6–6.5 mm vs. 7.1–9.8), and snout length (3.8–4.4 mm vs. 4.9–6.5), fewer Finger-III scansors (12 vs. 15– 18), Toe-IV scansors (15 vs. 16–22), supralabials (13, 14 vs. 16–19), ventrals (96–117 vs. 124–130), and precloacal pores (12 vs. 32–41), absence (vs. presence) of femoral pores, conspicuous limb spotting, and tail banding, and presence (vs. absence) of interorbital banding.

Redescription (based on the holotype [ Boettger, 1897] and three referred specimens). Measurements and scale counts of the holotype are provided below in brackets. Body small, slender, SVL 39.0 mm (male) [39.0], 34.5–42.4 mm (female); limbs well developed, moderately slender; tail slender; margins of limbs smooth, lacking cutaneous flaps or dermal folds; trunk lacking ventrolateral cutaneous fold.

Head size moderate, slightly differentiated from neck, characterized by only slightly hypertrophied temporal and adductor musculature; snout rounded in dorsal and lateral aspect; HW 113.2–128.0% MBW [115.6%], 58.2– 93.7% HL [58.2%]; HL 16.7–24.4% SVL [24.4%]; SNL 65.5–76.2% HW [76.2%], 44.4–62.3% HL [56.5%]; dorsal surfaces of head relatively homogeneous, with only slightly pronounced concave postnasal, internasal, prefrontal, and interorbital concavities; auricular opening small, ovoid, angled slightly anteroventrally and posterodorsally from beneath temporal swellings on either side of head; tympanum deeply sunken; orbit large; eye large, pupil vertical, margin wavy; limbs and digits relatively short; thighs moderately thicker compared to upper arms; tibia length 9.5–13.5% SVL [13.5%], 61.9–81.8% femur length [81.8%].

Rostral small, margin in wide heart shape in anterodorsal view, nearly as broad as high, sutured anterolaterally with anteriormost enlarged supralabials, projecting onto dorsal surface of head to point in line with anteriormost edge of nasal; nasal surrounded by first labial, rostral, one enlarged postnasal, and two enlarged supranasals; anteriormost supranasals separated by two or three small median scales; enlarged supranasals moderately larger than postnasals; circumorbitals 33–35 [35].

Total number of differentiated supralabials 13 or 14 [13], bordered dorsally by one row of differentiated, slightly enlarged snout scales; total number of differentiated infralabials 14 or 15 [14], bordered ventrally by two or three rows of slightly enlarged scales; chin scales slightly enlarged; postrictal scales undifferentiated; gulars small, round, nonimbricate, juxtaposed.

Dorsal cephalic scales fairly homogeneous in size, shape, disposition, and distribution; cephalic scalation slightly convex, round to oval scales; postnasal, prefrontal, internasal, and interorbital depressions; undifferentiated posterior head scales granular, slightly convex.

Axilla–groin distance 48.9–70.2% SVL [55.6%]; undifferentiated dorsal body scales roughly round, moderately convex, juxtaposed, relatively homogeneous in size, some with slightly raised edge, irregular in placement on individual scales across body; dorsals gradually transition to imbricate ventrals along lateral body surface; paravertebral scales between midpoints of limb insertions 211–218 [218]; ventrals between midpoints of limb insertions 96–117 [117]; scales on dorsal surfaces of limbs more imbricate than body dorsal scales; scales on dorsal surfaces of hands and feet similar to dorsal limb scales, heavily imbricate; ventral body scales flat, cycloid, strongly imbricate, much larger than lateral or dorsal body scales, relatively homogeneous in size.

Twelve enlarged scales in continuous precloacal series (pore-bearing series in males), arranged in a widely obtuse, “V”-formation; patch of slightly enlarged scales posterior to precloacal series, roughly 4–6 scale rows in width, three or four scale rows in length, forming an oval patch just posterior to precloacal series.

Digits moderately expanded and covered on palmar and plantar surfaces by bowed, unnotched, undivided scansors; digits with minute vestiges of interdigital webbing; mite eggs visible between distal subdigital scansors of some digits on hands and feet on all specimens examined; subdigital scansors of hands and feet bordered proximally (on palmar and plantar surfaces) by two or three slightly enlarged scales that form a near-continuous series with enlarged scansors; all digits clawed, but first (inner) claw greatly reduced; remaining terminal clawbearing phalanges compressed, with moderately sized recurved claws.

Tail relatively long compared to body, TL 33.0– 45.1 mm [33.0], 84.6–108.6% SVL [84.6%]; round, not heavily depressed; TH 83.2–100% TW [86.4%]; caudals similar in size to dorsals, subcaudals similar in size to ventral scales.

Coloration in life. “Above gray-brown, with darker clouded markings and on either side a dorsolateral row of about ten small, round white dots; lips and underside of body dirty white or with brownish markings or fine brown dots.” ( Taylor, 1922, p. 75).

Distribution, ecology and natural history. Pseudogekko brevipes is known only from a handful of specimens from the eastern Visayan islands of Bohol, Leyte, and Samar. Unlike the new species described below, P. brevipes possesses a distribution that may overlap with those of several other species in the genus ( P. ditoy and P. pungkaypinit ) in the eastern Philippines ( Siler et al., 2014b, c). As far as modern observations are concerned, only a single genetic record of this rare false gecko has been reported from the Municipality of Sogud on southern Leyte Island ( Siler et al., 2014b), and the holotype (SMF 8988) represents the only specimen ever recorded on Samar Island. Over the last decade, we have conducted several major biodiversity survey expeditions to multiple sites on Bohol, Leyte, and Samar islands; however, with the exception of the single genetic sample, we have yet to observe wild populations of real P. brevipes . Although at present there exists a general paucity of information about the ecology and natural history of P. brevipes , we believe this species to be an obligate primary forest dweller, and due to threats of habitat loss we expect that this species will likely qualify for a threatened category in the near future. Therefore, we recommend classification of P. brevipes as Vulnerable, based on the following criteria: VU B1ab(iii); D2 (IUCN, 2013). In addition, we recommend that continued biodiversity surveys of Bohol, Leyte, and Samar islands be conducted to increase our understanding of this species’ distribution and instraspecific diversity.

Figures

FIGURE 1. Map of the Philippine islands showing the sampling localities and recognized distributions for Pseudogekko brevipes and P. atiorum. Simplified phylogeny taken from Siler et al. (2014 b, c), showing hypothesized relationships of Philippine Pseudogekko resulting from Bayesian analyses of a concatenated multilocus molecular dataset shown for reference with Bayesian posterior probabilities.

FIGURE 2. Photographs and illustrations of the preserved holotype of Pseudogekko brevipes (SMF 8988). Photographs show ventral and dorsal views of the body and dorsal and lateral views of the head. Illustrations show ventral view of the head and the underside of the right hand. Scale bars = 3 mm. Photographs taken by GK and illustrations by CW.

FIGURE 3. Illustrations of precloacal pore series in adult male specimens of Pseudogekko atiorum (CAS 128963; paratype) and P. brevipes (SMF 8988; holotype). Scale bars = 2 mm. Illustrations by CDS and CW.