Hemiphyllodactylus goaensis, Khandekar & Parmar & Sawant & Agarwal, 2021

Khandekar, Akshay, Parmar, Dikansh S., Sawant, Nitin & Agarwal, Ishan, 2021, A new species of the genus Hemiphyllodactylus Bleeker, 1860 (Squamata: Gekkonidae) from Goa, India, Zootaxa 5027 (2), pp. 254-268 : 258-264

Hemiphyllodactylus goaensis sp. nov.

Figures 1–6 ; Table 3.

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Holotype. BNHS 2846 , SVL 30.2 mm, adult male, from Goa University, Taleigao, (15.46032°N, 73.83583°E; ca. 50 m asl.), North Goa district , Goa, India, collected by Dikansh S. Parmar on 22 November 2020.

Paratypes. BNHS 2847 , SVL 25.6 mm, sub-adult male, same data as holotype except coordinates (15.46041°N, 73.83544°E; ca. 50 m asl.), collected by Dikansh S. Parmar on 18 March 2020 ; BNHS 2848 , SVL 32.4 mm, adult female, from near Chandor , (15.26089°N, 74.04367°E; ca. 10 m asl.) South Goa district, Goa, India, collected by Rinku Kumar Gupta on 09 September 2020 .

Etymology. The specific epithet is a toponym for Goa state, to which the new species is currently restricted to.

Suggested common English name. Goan slender gecko.

Diagnosis. Hemiphyllodactylus goaensis sp. nov. can be diagnosed from congeners by the unique combination of snout-vent length up to 32.4 mm (n =3); five or six chin scales; postmentals not enlarged; 10–12 supralabials and 10 or 11 infralabials; 16–18 dorsal scales and 13 or 14 ventral scales at mid-body contained within one longitudinal eye diameter; four or five subdigital lamellae on the digit I of manus and pes; lamellar formula of manus 2222; lamellar formula of pes 2323 and 2333; males with nine or ten precloacal pores separated by 1–5 poreless scales from a series of 10–12 femoral pores on each thigh (n =2); no plate-like enlarged subcaudals; head with dark postorbital streak and longitudinal markings on nape, dark postorbital streak more or less well-defined and may continue until hindlimb insertions, longitudinal markings on nape extending just past forelimb insertions; dorsal pattern of broken dark longitudinal markings and light and dark speckling; postsacral marking with light-coloured anteriorly projecting arms indicated by broken streak extending anterior to hindlimb insertions; belly stippled with black.

Comparison with peninsular Indian congeners. Hemiphyllodactylus goaensis sp. nov. can be distinguished from all other Indian congeners on the basis of the following differing or non-overlapping characters: males with nine or 10 precloacal and 10–12 femoral pores (versus males with eight or nine precloacal and two or three femoral pores in H. arakuensis , six or seven precloacal and 6–8 femoral pores in H. aurantiacus , nine or 10 precloacal and six or seven femoral pores in H. jnana , nine precloacal and eight femoral pores in H. kolliensis , nine or 10 precloacal and six or seven femoral pores in H. minimus , eight or nine precloacal and 7–9 femoral pores in H. nilgiriensis , and 11 precloacal and 11 femoral pores in H. peninsularis ); males with 1–5 poreless scales between precloacal and femoral pores (versus 11–14 in H. arakuensis , 9–11 in H. aurantiacus , 10–12 in H. jnana , and 7–9 in H. nilgiriensis ); 16–18 mid-body dorsal scales in one eye diameter (versus 13–16 in H. arakuensis and H. aurantiacus , and 20 in H. peninsularis ); 13 or 14 mid-body ventral scales in one eye diameter (versus 9–13 in H. aurantiacus , 10–13 in H. kolliensis , and eight or nine in H. minimus ); lamellar formula of pes 2323 and 2333 (versus 2333 or 3333 in H. arakuensis ; 2233, 2333 and 3333 in H. aurantiacus ; 2222 in H. jnana , H. kolliensis , H. nilgiriensis and H. peninsularis ; 2332 or 2333 in H. minimus ,).

Description of the holotype. The holotype is in good condition except for a small 2.1 mm vertical cut on sternum region. Adult male, SVL 30.2 mm. Head short (HL/SVL 0.19), elongate (HW/HL 0.79), slightly depressed (HH/HL 0.44), distinct from neck ( Figure 2 ). Prefrontal region flat; canthus rostralis smoothly rounded, snout rounded in dorsal profile ( Figure 3A ). Snout short (SE/HL 0.45); slightly longer than eye diameter (ED/SE 0.59); scales on snout, canthus rostralis, forehead and interorbital region homogenous in shape, granular; scales on the snout and canthus rostralis slightly larger, conical and pronounced than those on occipital, forehead and interorbital regions, two rows bordering supralabials slightly larger and elongated ( Figure 3A, C ). Eye small (ED/HL 0.27); pupil vertical with crenulated margins; supraciliaries small, slightly mucronate, gradually increasing in size towards anterior of the orbit, those at the anterior end of orbit largest; ear opening roughly oval (greatest diameter 0.4 mm), eye to ear distance greater than diameter of eye (EE/ED 1.37); rostral wider than deep (rostral width/ height 3.0), undivided; single large supranasal above naris on each side, separated medially by three slightly smaller internasal scales; three postnasal on left side and two on right, marginally smaller in size than supranasals; rostral in contact with naris, supralabial I, supranasals and three small internasal scales on each side; naris small, circular; external naris surrounded by supranasal, rostral, supralabial I and three postnasals on left side and supranasal, rostral, supralabial I and two postnasals on right ( Figure 3C ). Mental subtriangular, bordered laterally by infralabial I on either side and posteriorly by three slightly enlarged chin scales; five scales touching internal edge of infralabials and mental from juncture of second and third infralabials on either side ( Figure 3B ). Labials large, supralabial I and infralabial I largest, gradually decrease in size posteriorly; supralabials (to midorbital position) eight on left and seven on right side; 11 supralabials (to angle of jaw) on left and 10 on right side; infralabials (to angle of jaw) 10 on left and 11 on right side ( Figure 3C ).

Body relatively stout (BW/SVL 0.15), marginally elongate (TRL/SVL 0.52), ventrolateral folds indistinct ( Figure 2A ). Scales on dorsal aspect of head and neck granular, slightly smaller than those on snout and forehead, those on dorsum slightly smaller than those on snout, flat and subimbricate; 18 scales contained within one eye diameter. Ventral scales much larger than dorsals, smooth, subequal, imbricate, subcircular, gradually increasing in size posteriorly, except three or four rows above cloaca which are much smaller; 14 scales contained within one eye diameter; gular region with much smaller, somewhat pointed, granular scales, becoming slightly larger, flattened and juxtaposed on anterior and lateral aspects. Scales on palm and sole flat and subcircular; scales on dorsal and ventral aspect of limbs flat, subequal and imbricate, those on anteriolateral aspect of thigh largest ( Figure 2B ). Forelimbs and hindlimbs short, stout; forearm short (FL/SVL 0.09); tibia short (CL/SVL 0.11). Digits with welldeveloped lamellar pad; digit I vestigial, without claw; digits II–V well developed, with free terminal phalanx arising from within lamellar pad, ending in a unsheathed, recurved claw; lamellar pads of all digits with basal series of undivided, transverse lamellae, expanding into large triangular apical lamellae, which are deeply notched except terminal lamella which is undivided; proximal lamellae/lamellar formula II–V: 2-2-2-2 (manus) and 2-3-3-3 (pes); basal lamellae of digits II–V: 3-5-5-4 (manus) and 4-5-6-3 on left and 4-5-4-5 on right (pes); transversely expanded lamellae on digit I: four on both manus and pes.

Tail regenerated, not segmented; tail much shorter than snout vent length (TL/SVL 0.49) ( Figure 2 ); scales on dorsal aspect of tail much larger than those on mid-body of dorsum, smooth, flat, subcircular and subimbricate, largest on dorsal side, gradually decreasing in size laterally. Scale on ventral side of the tail almost twice the size of those on the dorsal side of tail, smooth, flat and subimbricate. Two distinct hemipenial bulges at tail base, clearly visible when viewed laterally and ventrally; two enlarged, subequal postcloacal spurs on both sides, anterior one is largest. Angular series of nine precloacal pores separated from a series of 12 (left) and 10 (right) femoral pores by two (left) and five (right) poreless scales.

Colouration in life (holotype; Figure 4A ). Ground colour of dorsum of head, body and limbs light brown suffused with pink (dirty brown in preservative). Indistinct dark preorbital streak, two indistinct dark, discontinuous postorbital streaks that terminate beyond forelimb insertion, most well defined behind head to just beyond forelimb insertions (especially in preservative). Dorsum of occipital region and body with faint dark longitudinal markings and scattered light speckles. Limbs with dark and light speckling; few scattered orange spots near hindlimb insertions and on hindlimbs and tail. Postsacral marking yellowish cream, chevron-shaped, flanked anteriorly and laterally by black chevron; light anteriorly projecting arms indicated by broken yellow streaks extending anterior to hindlimb insertions (cream coloured in preservative). Regenerated tail finely speckled with dark and light markings; venter of tail off-white. Throat moderately and lateral edges of belly strongly stippled with dark spots and numerous dark scales, underside of limbs and precloacal region strongly pigmented.

Variation and additional information from paratypes. Mensural and meristic data for the type series is given in Table 3. There is a single sub-adult male (25.6 mm) and a single adult female (32.4 mm). Both paratypes resemble the holotype except as follows: female paratype BNHS 2848 with elongated calcium deposits on either side of the neck ( Figure 4B ), and fourth terminal phalange of left pes missing. Four chin scales bordering mental posteriorly in BNHS 2848 ; four chin scales bordering infralabial II in BNHS 2847 . Female paratype BNHS 2848 with original (except the tip which is regenerated) and complete tail, shorter than body (TL/ SVL 0.69); male paratype also with original but incomplete tail (tail length 7.2 mm); no caudal segments ( Figure 5 ). Original tail bright orange ventrally in paratypes, light orange dorsally with four indistinct dark bands in female paratype BNHS 2848 . Postorbital streak well defined in BNHS 2848 , discontinuous but extending beyond hindlimb insertions; dorsal longitudinal markings on neck; BNHS 2847 with dark preorbital streak, indistinct dark longitudinal markings and rows of longitudinally arranged light spots on dorsum of body. Calcium deposits on lateral sides of neck in BNHS 2848 cream coloured. Postsacral marking orange in both paratypes.

Distribution and natural history. This species is only known from two localities in Goa, where it was found as a human commensal. Specimens were collected by visual encounter at night from Goa University (North Goa district) and Chandor (South Goa district). On 18 March 2020 at 23:40 hrs, 1st individual (BNHS 2847) was found on a wall on the second floor of a building ~ 48 feet above the ground and ~ 10 feet above floor level. Second individual (BNHS 2848) was found in Chandor (South Goa) on 9 September 2020 at 2130 hrs it was found dwelling on a wooden curtain rod (approximately seven feet from the ground). Third individual (BNHS 2846) was found on 22 November 2020 at 2028 hrs on a wall approximately seven feet from the ground.

Behaviour and Diet. All specimens showed tail wagging behaviour and after a short stride or slow walk they also exhibited leaping behaviour. Hemiphyllodactylus goaensis sp. nov. are moderate to slow in movement but active hunters, in captivity they preyed upon small crickets, small moths, bugs and cockroaches. When larger insects (double in size than head of geckos) were offered, the geckos would grab them in their mouths and shake their heads with vigorous movements to tear the insects into pieces in order to eat them. Individual BNHS 2846 shed its skin in an almost single complete piece on 13 December 2020 at 2008 hrs, and four days preceding this the colouration became dull and during this period it did not prey upon offered insects.

Note. Recently, Agarwal et al. (2019) described three new species of Indian Hemiphyllodactylus ( H. arakuensis , H. jnana , and H. kolliensis ) and provided additional morphological data for H. aurantiacus based on freshly collected topotypic specimens. However, they did not provide museum numbers for the three new species nor for the topotypic H. aurantiacus specimens. Subsequently, Agarwal et al. (2020a) described two more species from Tamil Nadu and also provided museum numbers for topotypic H. aurantiacus , H. jnana and the paratypes of H. kolliensis . In the present work, we provide updated museum numbers for for all the Hemiphyllodactylus material dealt with by Agarwal et al. 2019, 2020a ( Table 4).

Figures

FIGURE 1. Type localities of Indian species of Hemiphyllodactylus and distribution of Hemiphyllodactylus goaensis sp. nov. (northern locality is type locality and southern is the other known locality) with major east-flowing rivers marked in blue; inset, maximum likelihood phylogeny of the aurantiacus group with bootstrap support> 70% and posterior probability of 1 shown at nodes (outgroups not shown).

FIGURE 2. Hemiphyllodactylus goaensis sp. nov. (holotype, BNHS 2846): (A) dorsal view of body, (B) ventral view of body. Scale bars 10 mm; photos by Akshay Khandekar.

FIGURE 3. Hemiphyllodactylus goaensis sp. nov. (holotype, BNHS 2846): (A) dorsal view of head, (B) ventral view of head, (C) lateral view of head. Scale bars 5 mm; photos by Akshay Khandekar.

FIGURE 4. live photos of Hemiphyllodactylus goaensis sp. nov. (A) male holotype, BNHS 2846, and (B) female paratype BNHS 2848. Photos by Akshay Khandekar.

FIGURE 5. Paratypes of Hemiphyllodactylus goaensis sp. nov. Scale bar 10 mm; photo by Akshay Khandekar.

FIGURE 6. Habitat of Hemiphyllodactylus goaensis sp. nov. from Goa University, Taleigao, North Goa district, Goa, India. Photo by Dikansh S. Parmar.