Gehyra nana Storr 1978
Creators: name: Doughty, Paul
name: Bourke, Gayleen
name: Tedeschi, Leonardo G.
name: Pratt, Renae C.
name: Oliver, Paul M.
name: Palmer, Russell A.
name: Moritz, Craig
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Reptilia
Squamata
Gekkonidae
Gehyra
Gehyra nana

description: Gehyra nana Storr, 1978
Northern spotted rock gecko
(lineages nana 1, nana 2, nana 4, nana 7 & nanamulti from Moritz et al. 2018) Figs. 5–7, 14
Holotype. WAM R28214, an adult male collected from the King Edward River, Western Australia (“presumably in 14°52'S, 126°12'E ”) on 8 June 1965 by A.K. Lee.
Paratypes (94). All WAM specimens, except as noted, from Western Australia (amendments from the type list of Ellis et al. [2018] that identified discrepancies between registration numbers provided in Storr’s description compared to the actual specimens based on archival records). R27750 [in error, R21359], R27751–52 [in error, R27551–51], R27757–62 [in error, R27557–62], R56639 [in error, R56839], Kalumburu; R28187, R28213, R28215–18, King Edward River; R40441, Augustus Is; R40469 (now MCZ R158546), R40470 (now MCZ R158547), R40471 (now MCZ R158548), R43147, R43157, Mitchell Plateau; R41391, Darcy Is; R41371–72, Heywood Is; R41428–31, Champagne Is; R41455, Bigge Is; R42704, 13 km NNE Argyle Downs; R43062–63, R43079–81, R56167, R56211, R56212, Crystal Creek; R43559–62, Pago; R44051–55, R44065–66, Sir Graham Moore Is; R44075, Anjo Point; R44088, Boongaree Is; R44110, South-west Osborne Is; R44144, St Andrew Is; R44157–65, Kingfisher Is; R44195 [in error, R99543], Melomys Is; R46668–72, R46706–07, R46710 [in error, R47010], R46883, R46884, R46831–32, R46837–38, Prince Regent River NR [NP]; R50330–32, R50400–03, R50414, R50465, R50507, R50675, R50783, R50797, R50802, R50811, Drysdale River NP; R56357, 2 km east of Mitchell River Falls.
Of the 94 G. nana paratypes, 33 have been identified as specimens of other species as follows: G. occidentalis (10 specimens)—R44157–65, R99543; G. koira koira (1 specimen)—R50402; G. multiporosa (9 specimens)— R41391, R41455, R44144, R46883–84, R46831–32 and R46837–38; G. granulum sp. nov. (13 specimens)— R40441, R41371–72, R41428–31, R44088, R46668, R46672, R50783, R56167, R56211. Although belonging to different species, they maintain their status as paratypes of G. nana.
Diagnosis. A Gehyra with small body size (mean 42 mm, range 34–55 mm SVL), no flap of skin between limbs, dorsal half of rostral deeply furrowed with groove, single internasal usually present, 2 postnasals of similar size, first supralabial taller and narrower than second, snout short and convex in lateral view, first digit of manus and pes without claw, mode of 6 (range 5–7) divided subdigital lamellae on fourth toe, mean of 15 (range 10–22) pre-cloacal pores in males arranged in a chevron pointing anteriorly. Background colouration dull light tan to brown with numerous small pale spots or short bars and large dark spots (not in contact) on dorsal surfaces that tend to form transverse rows on dorsum; no dark temporal streak behind eye.
Description. Body size small (mean 42.4 mm, range 33.6–55.3 mm SVL; n.b. of 155 specimens measured, only 5 exceeded 50 mm), trunk length moderate (TrunkL/SVL 0.32–0.49), body shape moderately robust and dorsoventrally flattened, moderately flattened head (HD/HL 0.44, 0.41–0.65) with short snout (SnEye/HL 0.44, 0.36–0.51), convex in lateral view, slight depression between curved poorly-defined canthal ridges; neck wide with only slight constriction, enlarged calcium glands in some females. Limbs moderate length (ArmL/SVL 0.11, 0.08– 0.13; LegL/SVL 0.12, 0.07–0.15); digits short; claw protruding from dorsal surface of expanded circular to oblong terminal toepad, no claws on anteriormost digit of manus and pes.
Nostrils rounded, directed laterally and dorsally, contacted by rostral, supranasal, two postnasal scales and first supralabial; supralabials 7–10; infralabials 6–9; rostral ~1.6 wider than high with a deep furrow ~50% of rostral height, a fine medial groove extends 25–75% of the height of the scale from dorsal edge; supranasals rounded, dorsal edge curved, ventral edge flat and in contact with rostral, supranasals typically separated medially by single large or 2–3 smaller internarial scales along dorsal edge of rostral; 2 similar-sized postnasals. First supralabial taller and narrower than second; mental narrow, angling inwards posterior to infralabials, terminating in triangular point from 1/3 to 2/3 height of inner chin shields; outer chin shields smaller than inner (~1/2 length), smaller irregularsized granular scales lateral to posterior half of outer chin shields; inner chin shields usually in contact with second infralabial but can be narrowly or less commonly widely excluded; first scale of parainfralabial row of scales usually fitting into a notch on postero-ventral edge of third infralabial, but sometimes with second infralabial; chin scale arrangements frequently asymmetric.
Scales on dorsum small, non-overlapping; scales near eyes becoming larger, scales on snout large and rounded; enlarged row of scales above supralabials; scales on ventrum flat and ~6– 8 x larger than those on dorsum, becoming granular anterior to arms; granular scales on gular region, increasing in size towards parainfralabial row and infralabials; scales on ventral surface of thighs and anterior to cloaca enlarged and flat; medial row of scales on tail greatly enlarged and much wider than long, bordered laterally by 1–2 rows of moderately enlarged scales, scales on dorsal and lateral surfaces of tail slightly enlarged and tending to be arranged in regular rows; regenerated tails with same relative scale proportions but less regular than in original tails.
Males with an average of 15 (range 10–22) pre-cloacal pores forming a shallow chevron with the apex pointed anteriorly, pores penetrating scale, apex pore is usually present; 2–3 enlarged protruding cloacal spurs to either side of cloaca (females with only slightly enlarged analogous scales). Tail cylindrical and long, tapering to fine point.
Colouration. In life, background colour of dorsal surfaces light to dark tan or brown, with pinkish to reddish hues; scattered brownish-black dark spots and more numerous pale white spots not in contact and tending to form alternating transverse rows; dark spots of similar size or slightly larger than pale spots; dark spots tending to have irregular edges whereas pale spots have neatly rounded edges; occasionally the pale or dark markings form short bars; typically a lightening of the background colour along the midline; usually no dark temporal streak posterior to eye; large dark spots usually absent from head anterior to eyes but with small pale spots present or with fine pale stippling; supralabials darkly stippled with maculated appearance formed by hiatus of pigment near sutures; infralabials, mental, chin shields and scales on outer edge of jaw with light to heavy dark stippling; upper surfaces of limbs with small dark and pale spots, continuing to dorsal surfaces of digits; ventrum pale off-white with some light brown stippling in centre, heavier stippling towards lateral edges; dorsal and lateral surfaces of original tails with alternating rows of pale and dark spots; regenerated tails with an admixture of dark and pale scales; ventral surface of tail as for ventrum. In preservative, the reddish hues are lost and the background colour is medium brown.
Habitat. This species has been collected from sandstone and other rock formations in open woodlands. Occurs under large flat rocks on open sandstone platforms as well as rocky creeks and gorges, including scree.
Occasionally found on trees, but always near rocky outcrops. It is generally found among small boulders and loose rock rubble, but can occur on larger open rock faces in the absence of larger Gehyra species such as G. koira Horner or G. pseudopunctata sp. nov.
Distribution. This species as redescribed here has the broadest distribution of any variegata group Gehyra in the AMT, ranging from Koolan Island in Western Australia through the Kimberley and Top End regions of the Northern Territory to Arnhem Land near the Gulf of Carpentaria (Fig. 1B). It is abundant in the northern (nana 4) and central (nanamulti) Kimberley, and extends from Koolan Island off the Yampi Peninsula east along the southern barrier ranges (King Leopold and Durack ranges), as far south as ~ 100 km south of Fitzroy Crossing, through Kununurra to the Victoria River-Bonaparte area (nana 1). Widespread in the Top End of the Northern Territory, represented by a western (nana 2) and eastern-Arnhem Land (nana 7) clades. South and east of the Roper River in the north-eastern Northern Territory, genetic analyses indicate that it is replaced by other lineages of the G. variegata group, including spotted varieties of G. versicolor Hutchinson, Sistrom, Donnellan & Hutchinson (Mt Isa region) and G. einasleighensis Bourke, Pratt, Vanderduys & Moritz (L. Ashman & Moritz, unpublished data).
Etymology. Storr used the word nana (Latin), meaning small, to describe this small-bodied species relative to larger forms of Gehyra.
Comparison with other species. This species complex differs from non-Australian Gehyra by the absence of webbing between third and fourth toes, absence of a skin fold along the posterior hindlimb, and moderate adult size (typical SVL <50 mm). Additionally, members of the G. nana complex can be distinguished from the G. australis group (which are largely restricted to the AMT) by smaller size (max SVL <58 vs> 65 mm) and divided subdigital lamellae (vs at least some undivided).
The distributions of G. nana species do not overlap those of the arid zone members of the G. variegata group with a similar spotted pattern such as G. punctata, G. pilbara Mitchell and G. montium Storr. However, these arid zone species can generally be distinguished by possession of a rich reddish background colour in life (Hutchinson et al. 2014) whereas G. nana is more light brown to tan. An exception is G. moritzi Hutchinson, Sistrom, Donnellan & Hutchinson, which is phenotypically very similar to G. nana but occurs in the south-central Northern Territory 1000 km away. Arboreal arid zone species such as G. purpurascens Storr, G. variegata and G. lazelli Wells & Wellington tend to be light purplish-brown with networks of dark lines, rather than well-defined spots and blotches as in G. nana. Diagnostic loci are presented in Appendix 2, and can be used to compare sequences from tail tips or other tissues for confident identification with minimum sequencing.
Gehyra nana can be distinguished from the G. variegata group species that also occur in the AMT as follows: from G. xenopus Storr, G. spheniscus Doughty, Palmer, Sistrom, Bauer & Donnellan and G. granulum sp. nov. by the absence of granules between proximal lamellae (vs present), and in the case of the former species, also much smaller size (max SVL 55 mm vs 79 mm); from G. occidentalis by fewer subdigital lamellae on the fourth toe (5–7 vs 7–10) and smaller body size (max SVL 58 mm vs 76 mm); from G. multiporosa by the absence of dark lateral head streaks (vs present), and fewer pre-cloacal pores in adult males (10–22 vs 15–54). Gehyra nana can be distinguished from the southern Kimberley species, G. girloorloo, by a combination of dorsal colouration in life (background colour pale to dark tan vs pinkish-grey; diffuse vs clear markings), robust body (vs gracile) and tail tapering from base to tip (vs thin tail); from G. pseudopunctata sp. nov. by smaller body size (34–55 vs 47–58), more numerous pre-cloacal pores (10–22 vs 7–11), fewer subdigital lamellae on the fourth toe (5–7 vs 7 or 8) and smaller pale and dark spots on the dorsum; and from the southern Kimberley, Great Sand Desert and northern Pilbara species G. kimberleyi, by a moderately flattened head (HD/HL 0.29–0.54) vs. deep head (HD/HL 0.40– 0.58) and small body size (34–55 mm vs 37–61 mm SVL for G. kimberleyi).
The restricted distribution of the small-bodied G. pluraporosa sp. nov. overlaps that of G. nana (lineage nana 4) in the northern Kimberley (Fig. 1). However, G. pluraporosa sp. nov. possesses numerous pre-cloacal pores in males (25–26 vs 10–22), the upper postnasal is larger than lower postnasal (vs similar in size in G. nana other species) and has a dorsal pattern with alternating poorly-defined pale and dark blotches or bars, overlain with pale stippling (vs relatively well-defined pale and dark spots not in contact on plain reddish-brown background in G. nana).
Gehyra nana most closely resembles G. paranana sp. nov., but differs in usually having 5 or 6 subdigital lamellae on the fourth toe whereas the latter usually has 7. In addition, the pale spots in G. nana tend to be smaller than the dark spots, whereas in G. paranana sp. nov. they are approximately equal in size, and the spots on G. nana also tend to be clearer than those of G. paranana sp. nov. (cf. Fig. 5, 7 vs 9).
description: Published as part of Doughty, Paul, Bourke, Gayleen, Tedeschi, Leonardo G., Pratt, Renae C., Oliver, Paul M., Palmer, Russell A. & Moritz, Craig, 2018, Species delimitation in the Gehyra nana (Squamata: Gekkonidae) complex: cryptic and divergent morphological evolution in the Australian Monsoonal Tropics, with the description of four new species, pp. 201-244 in Zootaxa 4403 (2) on pages 209-215, DOI: 10.11646/zootaxa.4403.2.1, http://zenodo.org/record/1212095