Gehyra paranana, Doughty & Bourke & Tedeschi & Pratt & Oliver & Palmer & Moritz, 2018

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, Zootaxa 4403 (2), pp. 201-244 : 215-217

Gehyra paranana sp. nov. Bourke, Doughty, Tedeschi, Oliver & Moritz

Litchfield spotted gecko

(lineage nana 3)

Figs. 5 , 8 , 9

Holotype. NTM R37057, an adult female collected from Dorat Road, Robin Falls area , Northern Territory (13.35278°S; 131.13361°E), on 21 September 2013 by P.M. Oliver, P. Skipwith and M. Hammer.

Paratypes (12). Northern Territory: NTM R20246 (male), Butterfly Gorge, 6 km east of Daly River crossing (13.73333°S; 130.73333°E) ; NTM R37831 (field# CCM0651 ) and NTM R37832 ( CCM0652 ) (females), Bullo River Station (15.65862°S; 129.65944°E) ; NTM R36578 and NTM R36579 (females), Bullo River Station (15.65766°S; 129.65933°E) ; NTM R36554 (male), Gurrandalng camp, Keep River National Park (15.87516°S; 129.051°E) ; NTM R37056 (male), Dorat Road, Robin Falls area (13.35278°S; 131.13361°E) ; NTM R37833 (CCM2881) (female), NTM R37834 ( CCM2883 ) and NTM R37835 ( CCM2885 ) (males), Tolmer Falls turnoff, Litchfield National Park (13.19654°S; 130.71394°E) ; NTM R37836 ( CCM2936 ) (female) and WAM R177563 ( CCM2937 ) (female), Florence Falls turnoff, Litchfield National Park (13.12641°S; 130.80463°E) .

Diagnosis. A Gehyra with moderately small body size (~ 50 mm, range 40–57 SVL), no flap of skin between limbs, dorsal half of rostral deeply furrowed with groove, single internasal usually present, 2 postnasals usually similar in size but if different then upper larger than lower, first supralabial slightly taller and narrower than second, 2 pairs of chin shields, first digit of manus and pes without claw, moderately flattened snout, snout straight to concave in lateral view, 7 divided subdigital lamellae on fourth toe, in adult males an average of 15 pre-cloacal pores (range 12–19) arranged in chevron pointing anteriorly. In life, moderately dark tan to brown background colour with pale and dark moderately large spots of similar size and not in contact on dorsum that tend to form transverse rows or coalescing to form short bars.

Description. Body size moderately small (mean 49.7 mm, range 39.7–56.7 mm SVL; trunk length moderate (TrunkL/SVL 0.40, 0.36–0.44), body shape moderately robust and dorsoventrally flattened, moderately flattened head (HD/HL 0.42, 0.38–0.44) and snout, with short snout (SnEye/HL 0.44, 0.42–0.46), straight to slightly concave in lateral view, depression between rounded canthal ridges; neck moderately constricted. Limbs moderate length (ArmL/SVL 0.10, 0.08–0.12; LegL/SVL 0.11, 0.09–0.13); digits short; claw protruding from dorsal surface of expanded circular to oblong terminal toepad, no claws on anteriormost digit of manus and pes; 7 pairs of subdigitial lamellae on fourth toe (one individual with 6); 1–3 granular scales between proximate one or two rows of lamellae in 3 of 13 specimens examined.

Nostrils rounded, directed laterally and slightly dorsally, contacted by rostral, supranasal, two postnasals of similar size but upper occasionally larger than lower, and first supralabial; supralabials and infralabials 7–9; rostral width ~1.7 x height with a deep furrow ~50% of rostral height, a fine medial groove extends 40–70% of the height of the scale from dorsal edge, surface of rostral with dimpled appearance; supranasals rectangular to round, dorsal edge straight or curved, ventral edge flat and in contact with rostral, supranasals typically separated medially by single small internarial scale (sometimes 2) along dorsal edge of rostral, postnasals of similar size, but upper occasionally larger than lower, first supralabial taller and narrower than second; mental narrow, angling inwards posterior to infralabials, terminating in triangular point, from 1/5 to 1/3 height of inner chin shields; outer chin shields smaller than inner (~1/2 length), with rounded lateral-posterior edges, smaller irregular-sized granular scales lateral to posterior half of outer chin shields; inner chin shields usually in contact or narrowly excluded to second infralabial; first scale of parainfralabial row of scales usually forming a notch on postero-ventral edge of second or third infralabial (if the latter, some granular scales frequently extend to contact second infralabial); chin scale arrangements frequently asymmetric.

Scales on dorsum small, non-overlapping; scales near eyes becoming larger, scales on snout large and rounded; slightly 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 scalation, but formed by more irregular scales.

Males (n = 6) with an average of 15 (from 12–19) pre-cloacal pores forming a shallow chevron with the apex pointed anteriorly, pores penetrating scale, apex pore is generally present; 2 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 dark tan to medium-brown with reddish hues; widely scattered brownish-black dark bars or spots and pale white spots of similar diameter or thickness not in contact and often (but not always) tending to form alternating transverse rows; dark spots usually forming irregularly-shaped bars, but some individuals with roundish spots; midline somewhat lightened in many individuals; dark temporal streak posterior to eye usually present; large dark spots almost extend to eye level on crown but small pale spots or fine stippling extending to snout; supralabials light to heavily stippled with dark pigment, often with maculated appearance formed by hiatus of pigment near sutures; infralabials, mental, chin shields and scales on outer edge of jaw with dark stippling, infralabials often with maculated appearance as for supralabials; upper surfaces of limbs with small pale spots, small dark spots variably expressed, continuing to dorsal surfaces of digits; ventrum pale off-white with light stippling in centre and denser towards lateral edges; dorsal and lateral surfaces of original tails with alternating pale and dark rows of spots; regenerated tails with an admixture of dark and pale scales, some forming longitudinal streaks; ventral surface of tail as for ventrum. In preservative, any reddish hues are lost and background colour is a medium brown.

Habitat. This species has been collected from sandstone rock formations in open woodland habitats, appearing to prefer large expanses of exposed sandstone such as large boulders and rock walls. It is sympatric with G. nana and G. koira ( australis group) at northern localities. The former is a smaller-bodied species that is more commonly found on smaller boulders and amongst rock rubble, whereas G. koira is much larger and prefers boulders and vertical crevices.

Distribution. Gehyra paranana sp. nov. occurs in the north-western Northern Territory ( Fig. 1 ). In the east it is abundant in Litchfield National Park, approximately 100 km south of Darwin, south to Butterfly Gorge on the Douglas River. Westernmost records are from the vicinity of Bullo Station near the border of Northern Territory and Western Australia. Recently genotyped specimens from Bradshaw Field Training Area also confirm its presence in the intervening Wingate Range (unpublished data).

Etymology. The specific name paranana refers to the morphological similarity of this species to G. nana , as in “parallel to nana ”.

Comparisons with other species. Gehyra paranana sp. nov. resembles G. nana closely, and the same comparisons to distinguish G. nana from other Gehyra above can largely be apply to G. paranana sp. nov. With respect to G. nana , all but one specimen of G. paranana sp. nov. possessed 7 subdigital lamellae on the fourth toe, whereas G. nana usually had 5 or 6. For body size, most G. paranana sp. nov. have SVL> 50 mm (maximum SVL is 56.7 mm), whereas most G. nana have SVL <50 mm; however, some G. nana from the western Top End (Mt Bundy, Edith Falls, Hayes Creek) do attain larger body size, overlapping the range of G. paranana sp. nov. The pattern of spots is also useful, as G. paranana sp. nov. has larger, less distinct, pale spots and dark markings compared to G. nana (cf. Fig. 5 ), with the dark markings often forming short bars or networks, especially a dark streak behind the eye (absent in G. nana ).

Owing to the close morphological resemblance of the two species, confirmation of identity is possible with genetics by obtaining a tissue sample (e.g. tail tip) to generate mtDNA SNPs and consulting the diagnostic loci provided in Appendix 2.

Figures

FIGURE 1. Distribution maps of species in the Gehyra nana group. A) Distribution of previously-described species and G. nana as redefined here. The distribution of the G.nana complex is represented in light green and based on over 100 genotyped specimens. For other species, symbols represent genotyped specimens. B) Distribution of the four new species described herein. Dots represent genotyped specimens.

FIGURE 5. Photos in life of the species described herein. A) Gehyra nana (lineage nana2) (NTM R37597) from Bradshaw Field Training Area, NT (S. Mahony), B) G.nana (nanamulti) (WAM R174051) from Drysdale River National Park, WA (R.J. Ellis), C) G. paranana sp. nov. (NTM R37601) from Bradshaw Field Training Area, NT (S. Mahony), D) G. pseudopunctata sp. nov. (not collected) from near Halls Ck, WA (S. Zozaya), E) G. granulum sp. nov. (WAM R171403) from Prince Regent River National Park,WA (P.Doughty), F) G.granulum sp.nov. (WAMR168561) from Byam Martin Island(P.Doughty), G)G. pluraporosasp. nov. (WAM R174024) from Theda Station, WA (R.J. Ellis).

FIGURE 8. Holotype of Gehyra paranana sp. nov. (NTM R37057) from Robin Falls area,NT (scale bar = 10 mm).

FIGURE 9. Variation within Gehyra paranana sp. nov. (scale bar = 10 mm).