Cyrtodactylus cayuensis Li, 2007

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

Expanded description of Cyrtodactylus cayuensis Li, 2007

Figures 10 , S 3; Tables 2, S 4

Chresonyms.

Cyrtodactylus khasiensis cayuensis – Li (2007)

Cyrtodactylus cayuensis – Agarwal et al. (2018: 337)

Cyrtodactylus arunachalensis – Mirza et al. (2021)

Materials examined.

(Fig. 10 ). Arunachal Pradesh: one male ( WII-ADR 1219 ) and one female ( WII-ADR 1218 ) collected from Balek village (28.0624 ° N; 95.2721 ° E; elevation 450 m a. s. l.), East Siang District on 29 October 2021 by Bitupan Boruah ; one male ( WII-ADR 1213 ) collected from Ramsing (28.6563 ° N; 94.9795 ° E; elevation 600 m a. s. l.), Mouling National Park, Upper Siang District on 27 October 2021 by Bitupan Boruah ; one female ( WII-ADR 1199 ) collected from Syrnyup stream (28.5340 ° N; 95.0305 ° E; elevation 890 m a. s. l.), Jengging, Mouling National Park, Upper Siang District on 26 October 2021 by Bitupan Boruah ; two males ( WII-ADR 695 and WII-ADR 696 ) and two females ( WII-ADR 697 and WII-ADR 698 ) collected from Potin (27.3478 ° N, 93.8497 ° E, elevation 900 m a. s. l.), Lower Subansiri District on 5 October 2019 by Bitupan Boruah ; one female ( WII-ADR 3017 ) collected near Glaw lake (27.6960 ° N; 96.4456 ° E; elevation 1200 m a. s. l.), Kamlang Tiger Reserve, Lohit District on 2 September 2022 by Abhijit Das, Bitupan Boruah and Naitik G. Patel ; one male ( WII-ADR 1682 ) and one female ( WII-ADR 1681 ) collected from Ezengo (28.1565 ° N; 95.8638 ° E; elevation 560 m a. s. l.), Lower Dibang Valley District on 3 August 2022 By Bitupan Boruah ; three females ( WII-ADR 453 , WII-ADR 454 and WII-ADR 459 ) collected from Jengging (28.5499 ° N; 95.0537 ° E; elevation 760 m a. s. l.) by Abhijit Das on 5 October 2018 ; one female ( WII-ADR 478 ) and one male ( WII-ADR 473 ) collected from 6 km northwest to Pasighat (28.0945 ° N; 95.2682 ° E; elevation 410 m a. s. l.) by Abhijit Das on 2 October 2018 .

Revised diagnosis.

Medium-sized gecko, SVL 61.2–83.5 mm in adult males and SVL 59.4–83.6 mm in adult females; 8–13 supralabials and 8–12 infralabials; 18–26 rows of bluntly conical and feebly keeled enlarged tubercles across mid-dorsum; 27–38 paravertebral tubercles between the level of axilla and groin; 28–44 mid-ventral scales; 13–21 subdigital lamellae beneath the fourth digit of manus; 11–23 subdigital lamellae beneath the fourth digit of pes; colouration and marking pattern variable; dorsally greyish-brown, pale-brown or pale-yellowish-brown; five to eight dark-brown bands consisting of irregular shaped and sized enlarged spots on back between axilla and groin, or dorsum with dark-brown reticulation; tail with 9–13 dark and 9–12 light bands alternatively arranged on top.

Description based on newly collected materials.

Medium-sized gecko, SVL 61.2–75.1 mm in males (n = 6) and SVL 59.4–83.6 mm in females (n = 11); head moderately large (HL / SVL = 0.25–0.28), dorsoventrally depressed, longer than width (HW / HL = 0.67–0.75), distinct from neck, broader at occipital region; snout 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 = 0.38–0.43), longer than orbit (OD / SO = 0.49–0.78); nostril 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; rostral wide, a short groove at the middle on top; granular scales at parietal region and occipital region intermixed with slightly large rounded granular tubercles, dense in occipital and temporal region and size increases towards nape; 9–13 supralabials present, size decreases towards angle of jaw; a series of scales, slightly larger than the loreal scales present above the supralabials; 8–12 infralabials, size decreases towards angle of jaw; two or three rows of slightly enlarged and narrow scales along the infralabials, posteriorly size of those decreases; rest of the gular scales are small, granular juxtaposed, nearly homogeneous, scales on throat are imbricate.

Habitus slender (BW / SVL = 0.16–0.22, TRL / SVL = 0.41–0.47), dorsoventrally depressed; dorsal scales granular, heterogeneous, intermixed with rounded, weakly keeled and bluntly conical tubercles irregularly arranged, continuing up to third or fifth segment of the tail, size of the tubercles increases towards posterior body, pronounced at sacrum and base of the tail, posteriormost rows indistinctly keeled; 15–21 rows of dorsal tubercles across mid dorsum; 27–38 paravertebral tubercles; ventrolateral fold present; ventral scales on chest and belly larger than those of dorsal, flat, smooth, cycloid, subimbricate to imbricate; 34–44 mid ventral scales; seven or nine distinct precloacal pores in male and 7–10 small precloacal pores in female; PcP followed by three to six unpored enlarged scales below.

Forelimbs and hindlimbs slender (FL / SVL = 0.13–0.15, CL / SVL = 0.16–0.18); digits strongly inflected at the joints, all bearing large recurved claw and enlarged subdigital lamellae, dorsal scales on forelimbs heterogeneous, granular juxtaposed, smooth and subimbricate at distal end of forearm; forearm intermixed with a few rounded, large tubercles; dorsal scales of hindlimbs granular intermixed with large, rounded, bluntly conical tubercles; thigh scales towards lateral and dorsolateral side are smooth and subimbricate; ventral scales of forelimbs granular, juxtaposed, mostly homogeneous; scales on palm heterogeneous, granular juxtaposed; scales on ventral side of hindlimbs slightly smaller than or nearly equal to those of belly, smooth, cycloid and subimbricate; scales on the knee, above cloaca and on thigh below the level of precloacal pores are smaller and granular; scales on soles heterogeneous, granular, juxtaposed to subimbricate.

Tail slender (TL = 58–97 mm), gradually tapering, segments indistinct; dorsal scales small, granular, juxtaposed at the base, posteriorly size increases, flat, smooth, subimbricate, heterogeneous in shape and size; large feebly keeled scales up to third to fifth segment of the tail, those on basal segment are pronounced and posterior rows with indistinct keel; subcaudal scales smooth, subimbricate, wider than that of dorsal, heterogeneous in shape and size; no enlarged plate like series of subcaudal scales; two to four bluntly conical spurs present at the base of the tail. Detailed morphological characteristics of the collected samples are provided in Table S 4.

Sequence divergence.

The intraspecific divergence within C. cayuensis ranges between 0.1–6.4 %. Among the two clades identified by bPTP, both clades have an intraspecific divergence between 0.1–4.3 % and 0.2–2.4 %, respectively. The divergence between these two clades range between 3–6.4 %.

Colouration in life.

Dorsal colour and marking pattern variable (Fig. S 3). Head and body greyish-brown, pale-brown to pale-yellowish-brown on top; head on top irregularly mottled with dark-brown, slightly enlarged dark-brown irregular patches may be present on occipital area; dark-brown postorbital stripe and loreal stripe present; a light stripe above loreal stripe and postorbital stripe may be visible; a few pale-yellow spots may be present on temporal and occipital region; supraciliary yellowish-brown; neck with short dark-brown streak with irregular edge or with irregular shaped patches; trunk dorsally with five to eight dark-brown bands consisting of irregular shaped and sized enlarged spots and posteriorly pale-yellowish or light-edged, these bands mid dorsally interrupted, or dorsum with dark-brown reticulation; limbs dorsally greyish-brown or pale-yellowish-brown or pale-brown with distinct or indistinct dark-brown reticulation; a dark-brown band on sacrum, band mid dorsally intersected; tail dorsally with 9–13 dark and 9–12 light bands alternatively arranged, bands are with irregular edged, anterior one or two dark bands may be mid dorsally intersected, dark bands are broad and light bands are comparatively narrow, dark bands are posteriorly becomes black or more dark-brown, while light bands become whitish; light bands may have a few dark-brown spots.

Distribution and natural history.

The type locality, Xizang (Tibet), China by C. cayuensis also appears to be widely distributed in Arunachal Pradesh, India (Fig. 3 B ), within an elevational range of 410–1200 m a. s. l. Cyrtodactylus cayuensis is widespread in the foothills of Arunachal Pradesh from the western part of the state, at Seijusa (Pakke Tiger Reserve) to the eastern part (Kamlang Tiger Reserve) and it has successfully spread across major tributaries of the Brahmaputra River, i. e., the Subansiri, Siang, Dibang, Lohit up to at least north of Noa-Dihing. Populations of C. cayuensis have been recorded in degraded evergreen forest as well as in undisturbed semi-evergreen and evergreen forests. Cyrtodactylus cayuensis is particularly abundant in the vegetation close to the picturesque Glaw Lake in the Kamlang Tiger Reserve. We observed individuals at night on shrubs and bedrocks (sedimentary rock) along small forest streams. We also encountered them on small trees up to a 2.0 m inside the forest at Jengging, Kamlang Tiger Reserve and Mehao Wildlife Sanctuary.

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 10. Cyrtodactylus cayuensis from India showing the variation in dorsal marking pattern. A WII-ADR 1219 (Balek), B WII-ADR 1681 (Ezengo), C WII-ADR 1199 (Jengging), D WII-ADR 1218 (Balek), E WII-ADR 454 (Jengging), F WII-ADR 1213 (Ramsing), G WII-ADR 698 (Potin), H WII-ADR 3017 (Glaw lake), I precloacal pores in WII-ADR 698, and J precloacal pores in WII-ADR 478. Scale bar: 10 mm. I, J not to scale.