Hemidactylus brookii Gray, 1845

Mahony, Stephen, 2011, Taxonomic revision of Hemidactylus brookii Gray: a re-examination of the type series and some Asian synonyms, and a discussion of the obscure species Hemidactylus subtriedrus Jerdon (Reptilia: Gekkonidae), Zootaxa 3042, pp. 37-67 : 46-50

Hemidactylus brookii Gray, 1845

( Figures 1 A, 2A, 3A, 3B)

Hemidactylus Brookii Gray, 1845:153 . (partim) Original type locality: “Borneo” and “ Australia ”.

? Gecko Tytleri Tytler, 1865:547 . Original type locality: “Moulmein”.

? Hemidactylus Murrayi Gleadow, 1887:49 . Original type locality: “Pimpri and Garvi, in the “Dangs”, …., at the northwest extremity of the Syhadri or Ghat range, between Khandesh and Surat ”.

? Hemidactylus luzonensis Taylor, 1915:93 . Original type locality: “Manila, Philippine Islands ”

Hemidactylus brookii brookii –– Loveridge, 1941:246.

? Hemidactylus mahendrai Shukla, 1983:81 . Original type locality: “suberbs [sic] of Kanpur of Uttar Pradesh”.

Lectotype by present designation. BMNH 1947.3.6.47 (formerly BM RR1934.9.1.49[.21.a]), adult male, “Borneo” (= Sarawak, Malaysian Borneo), presented by Sir Edward Belcher.

Paralectotype by present designation. BMNH 1947.3.6.49 (formerly BM RR1934.9.1.51[.21.b]), adult male, “ Australia ” (= Sarawak, Malaysian Borneo––currently mislabeled), presented by the Earl of Derby, presumably Edward Geoffrey Smith Stanley ( Das & Sukumaran 2006).

Etymology. The specific epithet was originally created as a patronym in honour of Sir James Brooke (1803– 1868), an acknowledged contributor of specimens to BMNH ( Gray 1845). Known as the “Rajah of Sarawak ”, formerly Governor of Sarawak from 1841, and Governor of Labuan and Consul-General to the Sultan of Brunei from 1846 ( Schleich & Kästle 2002).

Definition. Hemidactylus brookii can be distinguished from all currently described Asian members of Hemidactylus based on the following combination of characters: adult male SVL to 55.8 mm, TrL/SVL 38.5–38.9%; primary postmental shield width is subequal to that of the first infralabials, secondary pair broadly in contact with second infralabials; ear opening large EarL/HL 8.2–11.2%, obliquely oval; 16–19 regular longitudinal rows of dorsal tubercles, largest 6–7 times size of surrounding granules; two series of 12–13 precloacal-femoral pores separated medially from each other by a diastema of one non-pore-bearing scale, non-pore-bearing scale <50% the size of pored scales, scale row bordering anteriorly the precloacal-femoral pore series enlarged, ≥ size of pore-bearing scales; 5 lamellae under digit I and 7–8 under digit IV of pes, subdigital lamellae mostly divided on digit IV of manus and pes, enlarged lamellae series under digit IV of pes extend to the base of the digit; tail oval in cross-section without lateral denticulation, tubercles on anterior tail portion form elongated recurved conical spines, subcaudals completely transverse the tail width from the distal third of original tail; two medium sized conical cloacal spurs.

Comparisons. Hemidactylus brookii is here compared with the morphologically most similar Asian Hemidactylus species occurring east of the western Pakistan border. It differs from H. treutleri Mahony by its smaller size, SVL to 55.8 mm (vs. SVL to 70 mm), and 24–26 precloacal-femoral pores (vs. 14); from H. gujaratensis Giri, Bauer, Vyas and Patil by its lower number of subdigital lamellae on pes, five on digit I, 7–8 on digit IV (vs. 7–9 and 10–11, respectively), and precloacal-femoral pore series separated medially by one non-pore-bearing scale (vs. at least five); from H. parvimaculatus by precloacal-femoral pore series separated medially by one non-pore-bearing scale (vs. 2–4), and 0–1 divided lamellae on digit I and 2–4 on digit IV of pes (vs. 2–3 and 5–7, respectively).

For diagnosis from H. gleadowi , H. kushmorensis and H. tenkatei see the respective comparison sections for these species.

Condition of types. Lectotype fully intact with unbroken original tail. Paralectotype (BMNH 1947.3.6.49) with a small circular piece of skin missing from the parietal region and entire tail absent, otherwise in good condition. Paralectotype (BMNH 1947.3.6.48) referred here to H. tenkatei in good state of preservation, with less than half of the tail present but detached and digit I and II of the right pes missing.

H. brookii H. gleadowi H. kushmorensis

Description of lectotype. BMNH 1947.3.6.47, adult male. A summary of mensural and meristic data is provided in table 1. A medium sized species of Hemidactylus (SVL 55.8 mm); head distinct from neck, lores rounded and interorbital region flat, forehead not concave; snout longer than orbit diameter; scales on snout circular, domed, largest on the canthal region, of subequal size to enlarged tubercles on the parietal, becoming mixed over the frontal with small granular scales; supraoculars covered with homogenous, small granular scales; dorsal and lateral surfaces of the head posterior to the orbit covered with small granular scales densely mixed with enlarged domed tubercles, size increasing laterally and posteriorly; interorbital scales 8–10 across the narrowest point of the frontal; canthus rostralis rounded; pupil vertically elliptical, with crenellated edges; supraciliaries small and rounded, size increasing slightly anterodorsally, all lacking spines; ear opening deep, oval, obliquely orientated posterodorsally, a single small tubercle on the anterior edge of the right ear opening; orbit to ear distance slightly greater than diameter of orbits; rostral subrectangular, with medial groove dorsally, extending to half of the rostral depth; rostral depth slightly more than half its width; contacted by nostrils, supralabial I, one internasal and two circular, slightly enlarged supranasals; nostrils circular, oriented dorsolaterally, nostril narrowly in contact with supralabial I, two postnasals, supranasal and rostral; two scale rows separating eye from supralabials; 9/9 (left/right) supralabials; 9/8 (left/right) infralabials; mental subtriangular, wider than it is length (MenL/MenW 77.8%); two paired postmentals, primary pair subequally in contact with each other and the mental, secondary pair not in contact with each other, ~70% the size of the first and rounded posteriorly, each postmental is bordered posteriorly by smooth, circular granular scales; several rows of enlarged elongated scales border the lower edge of the infralabials, size gradually increasing laterally from the small throat granular scales; enlarged endolymphatic sac not visible.

Body slightly compressed dorsally; ventrolateral fold absent; dorsum covered with uniform, small flattened granular scales interspersed with large tubercles, those of the nape are smallest and conical, size increasing posteriorly, tubercles of the anterior paravertebral rows are longitudinally oval with a weak median keel, laterally and posteriorly becoming more conical to transversally oval, with or without a weak keel, largest are 6–7 times the size of surrounding granular scales; 16 non-linear rows at midbody, 34 in a paravertebral line from back of the skull to the area above the vent, intertubercle distance varies randomly; lateral and gular granular scales grade abruptly into large, smooth, subimbricate ventrals; preanal depression absent; precloacal-femoral pores number 13/13 (left/ right), a single non-pore-bearing scale ~50% the size of pored scales separates pore-bearing rows; anterior scale row to pored scales enlarged relative to pored scales and adjacent ventrals; precloacal scales between the pore series and the cloaca are not enlarged relative to ventrals.

Forelimbs slender; dorsal surface of the upper forelimb covered with granular scales posteriorly, ~3 times larger than dorsal granular scales, size increasing and becoming imbricate anteriorly and ventrally, dorsal surface of the lower forelimb covered with small granular scales of size subequal to those on the dorsum and intermixed with enlarged tubercles of subequal size to those on the nape, subimbricate scales of the upper forelimb extend anteriorly onto the dorsal surface of the manus; hind limbs relatively short; dorsal surface of the hind limbs covered in small granular scales densely interspersed with larger conical tubercles, largest being of equal size to the largest dorsal tubercles, ventral surfaces of hind limbs with flat subimbricate scales; ventral surface of the manus and pes covered with smooth, rounded granular scales; digits relatively short, flattened, a small curved claw on all digital tips; distal phalanges elevated; lamellae numbering on right manus (total: divided) I (6: 1), II (6: 2), III (6: 2), IV (7: 5) and V (6: 2); and on right pes I (5: 1), II (7: 4), III (7: 4), IV (7: 5) and V (5: 2); basal subdigital lamellae narrow; interdigital webbing absent.

Tail completely original; strongly compressed dorsally and oval in cross section, longer than snout to vent length; slightly constricted at the base and tapering gradually to a narrow tip; post-cloacal hemipenal bulge distinct; two enlarged, bluntly conical cloacal spurs on each side; longitudinal middorsal furrow present on the tail, lateral furrow absent; median subcaudal series begin on the second tail segment consisting of transversely enlarged, smooth, subimbricate scales, approximately 35% tail width on the fourth segment, laterally bordered by large posteriorly rounded subimbricate scales, which rapidly decreasing in size to become small granular scales laterally and dorsally; tail segments are barely distinguishable basally becoming indistinct distally, first segment with a transverse row of eight tubercles followed by rows of six, tubercles keeled, obliquely pointed posteriorly.

Colouration in preservative: Dorsal surfaces of the head, body, limbs and tail primarily mid brown. Dorsally two transverse rows of three large dark oval blotches from the nape to anterior to the forelimb insertion. Further rows of blotches join to form wide uneven transverse bars, three on the trunk and approximately eleven on the tail; a feint dark brown stripe from the nostril across the lores to the anterior orbit and from the posterior orbit to above the ear opening; further markings if present are indistinguishable due to fading of the specimen; entire ventral surface of the head, body, limbs and tail appear plain light beige, however under magnification individual scales have varying numbers of minute black specks; precloacal-femoral pores are dark brown. Colouration in life was not documented in the original description ( Gray 1845).

Variation. Variation of major mensural and meristic characters are presented in table 1. The paralectotype agrees well in overall morphology to that of the lectotype with the following deviations: left and right precloacalfemoral pore series consist of 12 pored scales each, the posterior edges of the median-most pored scales of both series are narrowly in contact with each other, the single ~50% smaller non-pore-bearing scale is present but positioned slightly forward, thus not fully separating the left and right pored series from each other; the posterior third of the mental shield is divided by an aberrant transverse groove, and enlarged tubercle absent from anterior edge of ear opening.

Distribution. As discussed above, I believe that one of the specimens collected from Borneo was at some stage accidentally mislabelled as the Australian specimen, therefore H. brookii s.s. is currently known only from the type locality of “Borneo”. According to Günther (1872), collections made by Edward Belcher, and later described by Gray (1845), originated from the “principality of Sarawak [Borneo]”, thus the lectotype locality is here further restricted to “ Sarawak, Malaysian Borneo”. Bartlett (1895) reports on further specimens collected by himself and H. Low from “Kuching” in western Sarawak and “ Sarawak ” respectively, deposited in the Sarawak State Museum, Kuching. Recently an additional population of H. brookii has been found at Loagan Bunut National Park (03°44’N, 114°14’E), Miri Division, Sarawak, Malaysian Borneo ( Das & Sukumaran 2006). I have not had the opportunity to examine these additional specimens from Sarawak to confirm whether any are conspecific with the lectotype. It is likely that H. brookii is not native to Borneo, thus the origins of the introduced lectotype population must be determined to verify further populations assigned to this species. The recent definition of H. brookii by Rösler and Glaw (2010) was based on specimens from Nepal. In light of information provided here (see “Discussion”), the likelihood of the Nepal populations representing H. brookii s.s. should be considered tentative. The additional localities of current questionable synonyms are not included here pending their taxonomic revision of type specimens.

Figures

FIGURE 1. Historical figures of the Hemidactylus brookii group taxa: A. H. brookii adult male lectotype (BMNH 1947.3.6.47) by present designation, from Gray (1867: Pl. 15, Fig. 2), later reprinted in Gray (1875: Pl. 15, Fig. 2); B. H. subtriedroides adult male paralectotype (ZSI 4135) by present designation, from Annandale (1905 b: Pl. II, Fig. 1); C. H. gleadowi not based on the original type series, from Boulenger (1890: 86, Fig. 27), later reprinted as H. brookii (Boulenger 1912: 42, Fig. 14; Smith 1935: 90, Fig. 28); D. H. gleadowi a syntype from Murray (1884 a: Fig. 3).