Pachydactylus visseri BAUER, LAMB & BRANCH 2006
Male of Pachydactylus visseri.
© M. Barts.
Female of Pachydactylus visseri.
© M. Barts.
Copula of Pachydactylus visseri in a terrarium.
© B. Rhyce
.
Hatchling of Pachydactylus visseri.
© M. Barts.
Habitat of Pachydactylus visseri. Namibia.
© M. Barts.
Originalbeschreibung / Original description
BAUER, A., T. LAMB & B. BRANCH (2006): A Revision of the Pachydactylus serval and P. weberi Groups (Reptilia: Gekkota: Gekkonidae) of Southern Africa, with the Description of Eight New Species. – Proc. California Acad. Sci., Fourth Series, 57 (23): 595–709. — Terra typica: Namibia, Karas Region, Karasburg District, Ai-Ais Nature Reserve, c. 3 km N Orange River (28°12′26″S, 17°16′43″E)
ETYMOLOGY.— The specific epithet is a patronym honoring John D. Visser, an important contributor to southern African herpetology who kindly provided several hundred specimens from his personal collection for use in this study. The name is constructed in the masculine genitive. The epithet also reflects the occurrence of the species in the Fish (Vis) RiverValley.
DIAGNOSIS.— A relatively large species, to 48.5 mm SVL (PEM R 4638). Pachydactylus visseri may be distinguished from all other members of the P. serval/weberi group by the combination of the following characters: nasal region not inflated; rostral excluded from nostril; supranasals in broad or narrow contact; scales on snout and canthus granular, rounded to oval, flattened to weakly domed, much larger than granular scales of interorbital and parietal regions; small, rounded, conical tubercles, much smaller than snout scales, interspersed among granules of interorbital and parietal regions; dorsal scalation heterogeneous, with moderately large (6–9 times dorsal granules), oval, distinctly keeled arranged in 16–18 regular rows, largest on midflanks; thighs bearing enlarged keeled tubercles; toes relatively short, toe pads relatively narrow; typically five undivided lamellae beneath digit IV of pes; tail to at least 120% of SVL, annulate, bearing whorls of moderately large, pointed, weakly to strongly keeled tubercles; adult pattern a series of distinct, wide, pale (cream to beige) transverse bands separated by thinner dark brown bands. Six bands (rarely seven) anterior to sacrum (one on nape, one across shoulders, four evenly spaced between axilla and hindlimb insertion); tail with strongly contrasting cream and dark brown bands of approximately equal width (Figs. 109–110). Juvenile pattern similar to adult (Fig. 111).
DESCRIPTION (based on holotype).— Adult male. Snout-vent length (SVL) 38.6 mm. Body relatively depressed, relatively long (TrunkL/SVL ratio 0.45). Head elongate, large (HeadL/SVL ratio 0.32), narrow (HeadW/HeadL ratio 0.59), moderately depressed (HeadH/HeadL ratio 0.36), distinct from neck. Lores and interorbital region moderately inflated. Snout short (Sn-Eye/HeadL ratio 0.34), much longer than eye diameter (OrbD/Sn-Eye ratio 0.72); scales on snout and forehead smooth, flattened to weakly domed; large on snout and canthus becoming granular on interorbital region with larger (3–4 times parietal granules) weakly conical tubercles interspersed; scales on snout much larger (5–10 times parietal granules). Enlarged (2–3 times parietal tubercles), conical tubercles regularly scattered across temporal region and occiput, as far posterior as nape. Eye moderately small (OrbD/HeadL ratio 0.24); orbits without extra-brillar fringes; 5 supracilliary scales at posterodorsal corner of orbit bearing very small spines; pupil vertical, with crenelated margins. Ear opening oval, vertically oriented, small (EarL/HeadL ratio 0.07); eye to ear distance slightly greater than diameter of eyes (EyeEar/OrbD ratio 1.05). Rostral approximately 50% as deep (0.7 mm) as wide (1.4), no rostral groove, contacted by two enlarged supranasals and first supralabials; nostrils oval, oriented laterally, each surrounded by two postnasals, supranasal, and first supralabial; supranasals in contact anteriorly, separated by a single granule posteriorly; dorsal postnasals larger than ventral postnasals, separated by 3 granules; nostril rims not inflated, bordered posteriorly by a slight depression; one row of scales separate orbit from supralabials; mental wedge-shaped, tapering posteriorly, approximately 2.2 times deeper (1.7 mm) than wide (0.8 mm); no enlarged Postmentals or chin shields. Supralabials to angle of jaws 11/11 (8/9 to mid-orbit); infralabials 9/9; interorbital scale rows at midpoint of orbit 25 (7 across narrowest point of frontal bone).
Dorsal tubercles large (8–10 times size of adjacent scales), largest on midflanks and smallest along dorsal midline and on anterior one third of trunk, oval, with a pronounced median keel, forming 18 regular longitudinal rows on trunk; each tubercle surrounded by rosette of small granular scales; ventral scales flattened, oval subimbricate to imbricate, becoming larger posteriorly, largest on posterior abdomen and in precloacal region, approximately 35 between lowest granular rows on flank at midbody; tubercular scales on dorsum at midbody larger than ventral scales at same level; chin granules approximately one third to one fourth size of ventral scales, increasing in size gradually on throat. No preanal or femoral pores. Scales on palm, sole, and ventral surface of forelimb smooth, granular; scales on ventral aspect of hindlimbs enlarged, continuous with enlarged scales of precloacal region; scales on dorsal aspect of forelimb smooth, subimbricate proximally, with small conical tubercles intermixed among more strongly imbricate scales distally; scales on dorsum of thigh and crus greatly enlarged, strongly keeled.
Forelimbs moderately long, stout (ForeaL/SVL ratio 0.15); hindlimbs long (CrusL/SVL ratio 0.18); digits relatively short, claws absent; subdigital scansors, except for distalmost, entire, present only on distal portion of toes, approximately 1.5 times wider than more basal (non-scansorial) subdigital scales; interdigital webbing absent. Relative length of digits (manus): III > IV > II > V > I; (pes): IV > III ~ V > II > I. Subdigital scansors (excluding small distal divided scansor) I (3), II (4), III (4), IV (4), V (4) – manus; I (3), II (4), III (5), IV (5), V (5) – pes.
Tail (based on paratypes) sub-cylindrical, depressed; original tail longer than snout-vent length (TailL/SVL ratio 1.20; based on TM 35455); tail relatively thin basally, tapering, with distinct whorls of scales; each transverse row of enlarged, oval, pointed, strongly keeled tubercles separated by 3 rows of smaller scales; adjacent keeled dorsal caudal tubercles generally separated by a single smaller scale; subcaudal scales rhomboidal to pentagonal, imbricating; midventral caudal scales enlarged relative to adjacent scales (10+ times size of dorsal caudal scales); two enlarged, pointed, posterodorsally-projecting postcloacal spurs on each side of tailbase, anterior considerably larger than posterior.
Coloration (in life): Dorsum with alternating pale (cream to beige with pinkish tinge) and dark (mid-brown with darker margins) transverse bands, pale bands wider than dark, narrowing on flanks. Anterior most band across nape, second over shoulders, four remaining bands evenly distributed between axilla and hindlimb insertion. A mid-brown streak extending from nostril through middle of orbit and above ear to occiput, forming anterior border of pale nape band; a second, more diffuse brown stripe from labials, through ear to meet posterior dark border of pale nape band. Snout with diffuse, symmetrical brown markings, fading in interorbital region; diffuse brown markings over center of parietal table. Labials white with mid-brown pigment extensive on posterior labials, anteriormost labials with pigment limited to center of scales. Forelimbs relatively uniform light brown; hindlimbs with diffuse mid-brown barring basally. Tail (based on TM 35455) with alternating light (light brown or beige basally, cream to whitish distally) and dark (mid- to dark brown) bands of approximately equal width. Venter beige to cream, unpigmented except for scattering of fine brown speckles under limbs and at edges of chin and flanks.