Cyrtodactylus barailensis Boruah, Narayanan, Deepak & Das, 2024

Boruah, Bitupan, Narayanan, Surya, Aravind, Neelavar Ananthram, Lalronunga, Samuel, Deepak, V. & Das, Abhijit, 2024, Description of six new species of Cyrtodactylus Gray (Squamata: Gekkonidae) from northeastern India, Vertebrate Zoology 74, pp. 453-486 : 453-486

Cyrtodactylus barailensis Boruah, Narayanan, Deepak & Das sp. nov.

Figure 5 ; Tables 2, S 2

Holotype.

Adult female ( WII-ADR 971 ), from Athibung (25.54199 ° N; 93.6307 ° E; elevation 740 m a. s. l.) (Fig. 3 A ), Peren District, Nagaland, collected by Abhijit Das and Bitupan Boruah on 14 August 2021.

Diagnosis.

Medium-sized gecko, SVL at least 68.8 mm in adult female; supralabials 9–12 and infralabials nine; 12 or 13 lamellae beneath the digit IV of manus; 17 lamellae beneath digit IV of pes; 17 feebly keeled and bluntly conical tubercles across mid dorsum and 32 paravertebral tubercles; 36 smooth mid-ventral scales between ventrolateral folds; at least 10 small precloacal pores in female; head on top pale-brown with purplish tinge; dark-brown postorbital stripe continuing to above the ear opening; a dark-brown cross bar with irregular edges on nape; indistinct pale-yellow patch on occipital region; dorsally and laterally neck and back pale yellowish-brown with dark-brown irregular reticulation.

Description of holotype.

Holotype well preserved except an incision below left axilla ventrolaterally. Snout-vent length 68.8 mm. Head moderately large (HL / SVL = 0.26), dorsoventrally depressed, longer than width (HW / HL = 0.65), oval, distinct from neck, broader at occipital region; snout tip rounded in both dorsal and lateral view; loreal region convex; canthus rostralis rounded, indistinct; interorbital space flat; a longitudinal furrow on dorsal surface of the snout; snout short (SO / HL = 0.39), longer than orbit (OD / SO = 0.59); nostril rounded, opening directed posterolaterally; ear opening oblique; scales on head heterogeneous, largest on snout and loreal region, posteriorly smaller in upper eyelid, interorbital space and occipital region, granular juxtaposed; scales on upper eyelids heterogeneous, supraciliaries outwardly sharp giving serrated appearance in dorsal view, size anteriorly and posteriorly decreases, largest at the anterodorsal region; rostral wide, a short groove at the middle on top; rostral connected with nasals, supranasals and first supralabials; a single scale between the supranasals, larger than the rest of the granular snout scales; granular scales at parietal, occipital and temporal region intermixed with slightly larger rounded and bluntly conical granular tubercles starting from the level of posterior margin of the upper eyelids, smaller in parietal region, size increases towards nape; supralabial 12 on right side and nine on left side, supralabials count up to midorbit is eight on right side and six on left side, size decreases towards angle of jaw; a series of narrow, enlarged scales above the supralabials between nostril and anterior orbital border; mental triangular, connected with first infralabials and inner postmentals; nine infralabials on both side, size decreases towards angle of jaw; inner pair of postmentals are larger than the outer postmentals; posterior margin of the inner postmentals bordered by eight granular scales of different size; two rows of slightly enlarged, narrow scales, larger than gular scales present along the infralabials starting below the outer postmentals, posteriorly size decreases; gular scales granular, juxtaposed, homogeneous, size increases towards the throat where they become imbricate.

Habitus slender (BW / SVL = 0.16, TRL / SVL = 0.47), dorsoventrally depressed; dorsal scales granular, rounded, heterogeneous, intermixed with densely placed rounded, weakly keeled and bluntly conical tubercles, irregularly arranged, continues to seventh segment of the tail, size increases towards posterior body and pronounced at the base of tail; 17 dorsal tubercles across mid dorsum; 32 paravertebral tubercles; ventrolateral fold weak; ventral scales larger than those of dorsal, flat, smooth, cycloid, subimbricate to imbricate, largest on posterior part of the belly, 36 mid-ventral scales between ventrolateral folds; 10 small precloacal pores arranged in an inverted “ V ” shaped continuous series, followed by a series eight unpored, enlarged scales below it.

Forelimbs and hindlimbs slender (FL / SVL = 0.14, CL / SVL = 0.18); digits strongly inflected at the joints, all bearing large recurved claw and enlarged subdigital lamellae; lamellae count beneath digit IV of right and left manus (given as basal + distal) is 5 + 7 and 5 + 8 respectively; lamellae count beneath digit IV of both right and left pes (given as basal + distal) is 8 + 9; dorsal scales on forelimbs heterogeneous in size; hind arm scales smooth and subimbricate; forearm scales small and granular towards proximal and towards distal end it is smooth, cycloid and imbricate; forearm scales intermixed with enlarged feebly keeled tubercles; dorsal scales of hindlimbs heterogeneous, intermixed with densely placed large, rounded and bluntly conical tubercles; scales on inner lateral and dorsolateral side of the thighs smooth, large and imbricate, rest of the scales are granular; scales on tibia are small, granular juxtaposed; ventral scales of forelimbs granular, juxtaposed, mostly homogeneous; scales on palm heterogeneous in shape and size, granular juxtaposed; ventral scales of hind limbs smaller than those of belly, smooth, cycloid and subimbricate; scales on the knee, above cloaca and on thigh below the level of precloacal pores smaller and granular; scales on soles heterogeneous, granular, juxtaposed to subimbricate.

Tail complete, posterior 6 mm regenerated (TL = 64 mm), slender, gradually tapering towards tip; tail segments indistinct; dorsal scales small, granular, juxtaposed at the base, posteriorly size of the scales increases, flat, smooth, subimbricate, heterogeneous in shape and size; enlarged feebly keeled scales up to seventh segment of the tail, those on basal segment are pronounced; subcaudal scales smooth, subimbricate, wider than that of dorsal, heterogeneous in shape and size; no enlarged plate like series of subcaudal scales; four bluntly conical spurs on both sides of the tail base.

Colouration in life.

Head on top pale-brown with purplish tinge, indistinct brown irregular spots on occipital region; a short brown streak behind the posterior corner of the upper eyelid; a broad, dark-brown postorbital stripe continuing to above the ear opening; area between these two postorbital streaks is paler than dorsal head colour; an indistinct brown loreal stripe covering the nasal and an indistinct pale stripe above it; indistinct pale-yellow patch on occipital region; lips and mandibular region paler with indistinct yellow spots; dorsally and laterally neck and back pale yellowish-brown with dark-brown irregular reticulation starting from neck to sacrum; a dark-brown cross bar with irregular edges on nape; limbs pale-yellowish-brown with dark-brown reticulation; digits with alternative dark-brown and pale-yellow bars; tail with alternative 11 dark and 10 light bars in the original part, dark bars posteriorly more darker and broader; light bars posteriorly more whitish, first bar at the base of tail broken into two spots; fourth and fifth bar connected on left side; ventrally head, trunk and limbs whitish; tail with irregular brown and pale-yellow patches (Fig. 5 I ).

Colouration in preservative.

Top of head pale-greyish-brown; neck, back, limbs and tail dorsally light-grey with dark-brown markings; marking pattern visible as those in life condition; ventrally whitish with brown specks on tail.

Comparison.

Cyrtodactylus barailensis sp. nov. differs from C. aaronbaueri by fewer dorsal tubercle rows, DTR 17 (vs. DTR 22–28), 10 precloacal pores (vs. 6–8 pitted precloacal scales in female); differs from C. agarwali by fewer dorsal tubercle rows, DTR 17 (vs. 21–25); differs from C. aunglini by fewer mid-ventral scale rows, MVSR 36 (vs. MVSR 47–49), 32 paravertebral tubercle (vs. PVT 36–45), 17 dorsal tubercle rows (vs. DTR 21–26); differs from C. bengkhuaiai by having fewer dorsal tubercle rows, DTR 17 (vs. DTR 22–26), 10 precloacal pores (vs. 6–8 pitted precloacal scales in females); differs from C. brevidactylus by fewer dorsal tubercle rows, DTR 17 (vs. DTR 27–30), fewer paravertebral tubercles, PVT 32 (vs. PVT 38–42), enlarged dark blotches on head and dorsum absent (vs. large dark blotches on dorsum between nape and sacrum); differs from C. chrysopylos by presence of precloacal pores (vs. PcP absent in female), fewer mid-ventral scales, MVSR 36 (vs. MVSR 37–55); differs from C. dianxiensis by smaller body size, SVL 68.8 mm (vs. SVL 75 mm), presence of precloacal pores (vs. PcP absent in female), fewer subdigital lamellae, 12 or 13 under fourth finger and 16 under fourth toe (vs. 16 or 17 under fourth finger and 19 or 20 under fourth toe); differs from C. gansi by fewer dorsal tubercle rows, DTR 17 (vs. DTR 20–25), ventrolateral fold present on trunk (vs. absent), fewer precloacal pores, PcP 10 (vs. PcP 13 in female); differs from C. jaintiaensis by much smaller body size, SVL 68.8 mm (vs. SVL 96.2 mm in female), fewer mid-ventral scale rows, MVSR 36 (vs. MVSR 40–42), fewer precloacal pores, PcP 10 (vs. 12 PcP in female); differs from C. kiphire sp. nov. by the number of paravertebral tubercles 32 (vs. PVT 26 or 29); differs from C. lungleiensis by fewer dorsal tubercle rows, DTR 17 (vs. 24–28), 10 precloacal pores (vs. 5–7 pitted precloacal scales in females); differs from C. montanus by fewer dorsal tubercle rows, DTR 17 (vs. DTR 21–23), fewer paravertebral tubercles, PVT 32 (vs. PVT 37–43), precloacal pores present (vs. PcP absent in female); differs from C. myaleiktaung by fewer mid-ventral scale rows, MVSR 36 (vs. MVSR 57), precloacal pores present (vs. PcP absent), broad regular dark bands absent on dorsum (vs. present); differs from C. nagalandensis by presence of 10 precloacal pores (vs. six pitted precloacal scales in female), 32 paravertebral tubercles (vs. PVT 35–37); differs from C. namtiram by fewer dorsal tubercle rows, DTR 17 (vs. DTR 21); differs from C. ngopensis by presence of 10 precloacal pores in female, (vs. 0–6 pitted precloacal scales in female); differs from C. septentrionalis by fewer dorsal tubercle rows, DTR 17 (vs. DTR 23 or 24), less paravertebral tubercles, PVT 32 (vs. PVT 38–42), 10 precloacal pores present (vs. 14 precloacal scales with indistinct depression in female); differs from C. siahaensis by fewer dorsal tubercle rows, DTR 17 (vs. DTR 22–24), presence of precloacal pores in female (vs. PcP absent in female); differs from C. vairengtensis by the number of dorsal tubercle rows, DTR 17 (vs. DTR 22–23), 32 paravertebral tubercles (vs. PVT 34–39), 10 precloacal pores present (vs. 5–9 precloacal pits in female). Morphological differences with other members of khasiensis group is presented in Table 2 .

Sequence divergence.

Cyrtodactylus barailensis sp. nov. has a high genetic divergence of 10.9 % from its closely related C. namtiram . With other members of the clade, C. kiphire sp. nov. has a genetic divergence of 10.7 % and 22.3 % in the ND 2 gene.

Etymology.

The specific epithet is a toponym derived from the name of the hill range “ Barail ” where the type locality of the species lies.

Suggested common name.

Barail Hills bent-toed gecko.

Distribution and natural history.

During our two-day survey we only located a single individual of this species. Thus, the new species is currently known only from the type locality, in Peren District, Nagaland, India. We recorded this species on the trunk of a small tree at a height of approximately 2 m from the ground in the Athibung Reserve Forest at approximately 20: 00 hrs on 14 August 2021. The forest type is semi-evergreen with relatively little anthropogenic pressure.

Figures

Figure 3. Map showing geographic distribution of the clades within the khasiensis group. A type localities of the members of the four clades in the Indo-Burma region: 1 Cyrtodactylus septentrionalis, 2 C. guwahatiensis, 3 C. urbanus, 4 C. kazirangaensis, 5 C. siangensis sp. nov., 6 C. cayuensis, 7 C. namdaphaensis sp. nov., 8 C. bapme, 9 C. karsticola, 10 C. agarwali, 11 C. exercitus, 12 C. jaintiaensis, 13 C. khasiensis, 14 C. barailensis sp. nov., 15 C. nagalandensis, 16 C. kiphire sp. nov., 17 C. namtiram, 18 C. vairengtensis, 19 C. manipurensis sp. nov., 20 C. mombergi, 21 C. dianxiensis, 22 C. tripuraensis, 23 C. montanus, 24 C. aaronbaueri, 25 C. bengkhuaiai, 26 C. ngopensis, 27 C. lungleiensis, 28 C. ngengpuiensis sp. nov., 29 C. siahaensis, 30 C. gansi, 31 C. myaleiktaung, 32 C. brevidactylus, 33 C. aunglini, 34 C. chrysopylos, 35 C. ayeyarwadyensis; B cayuensis clade, green star (type locality of C. siangensis sp. nov.), pink star (type locality of C. cayuensis), pink triangle (C. “ arunachalensis ”), pink circle (C. cayuensis recorded in this study) (numbers correspond to the locality given in Table 1).

Figure 5. Holotype of Cyrtodactylus barailensis sp. nov. (WII-ADR 971). A dorsal and B ventral view of the whole body; C dorsal, D ventral, and E lateral view of head; F dorsal tubercles on trunk; G ventral view of left manus, and H left pes. I C. barailensis sp. nov. in life. Scale bar: 10 mm.