Hemidactylus festivus, Carranza & Arnold, 2012

Carranza, Salvador & Arnold, Edwin Nicholas, 2012, 3378, Zootaxa 3378, pp. 1-95 : 40-46

Hemidactylus festivus sp. nov.

( Figs. 2, 5D, 7, 17–19, Table 1; Appendix I; Appendix IIID)

MorphoBank M95305 – M95421 M99719 – M99810

Hemidactylus yerburii Arnold, 1977: 101 (part.); Arnold, 1986: 283 (part.); Arnold, 1986: 420 (part.); Schätti and Desvoignes, 1999: 52 (part.); van der Kooij, 2000: 113 (part.); Sindaco and Jeremcenko, 2008: 117 (part.).

Holotype

BMNH1977.977 , female from Wadi Ayoun , 670 m, Dhofar region ( South Oman) 17.24671’ N 53.88774 ’E WGS84, collected in October 1977 by E.N. Arnold ( MorphoBank M95339 – M95353 ). Paratypes: BMNH1977.978 , female, same collecting data as Holotype (MorphoBank M95354 – M95367 ); BMNH1977.976 , female, same collecting data as Holotype (MorphoBank M95323– M95338 ); BMNH1977.979 , female, same collecting data as Holotype (MorphoBank M95368 – M95379 ); BMNH1977.980 , female, same collecting data as Holotype (MorphoBank M95380 – M95392 ); BMNH1977.981 , female, same collecting data as Holotype (MorphoBank M95393 –M95407); IBES7419 , female from 20 km South of Thumrait, 586 m, Dhofar region ( South Oman) 17.4596’ N 54.0446 ’E, collected in October 2010 by S. Carranza and F. Amat (MorphoBank M99801 – M99810 ); IBES7159 , male from Wadi Ayoun , 670 m, Dhofar region ( South Oman) 17.24671’ N 53.88774 ’E WGS84, collected in May 2011 by S. Carranza, E. Gómez-Díaz and F. Amat (MorphoBank M99733 – M99743 ); ONHM3708 , male, same collecting data as IBES 7159 (MorphoBank M99744 – M99753 ); IBES7605 , male, same collecting data as IBES 7159 (MorphoBank M99754 – M99763 ); IBES8062 , male from Wadi Ayoun, 670 m, Dhofar region (South Oman) 17.24671’ N 53.88774 ’E WGS84, collected in October 2010 by S. Carranza and F. Amat (MorphoBank M99764 – M99773 ).

Other material examined

Five vouchers listed in Appendix I under H. festivus sp. nov. and not mentioned above. Samples AO126, AO82, AO122, AO120, AO154, AO121, JS1, JS12, JS15, JS70, JS71, JS72, JS73, JS85, and JS86 were included in the molecular analyses only (Table 1).

Diagnosis

A medium-sized Hemidactylus with a maximum recorded SVL of 53.6 mm; with a mean of 13.3 (12–15) longitudinal rows of enlarged dorsal tubercles at mid-body; adhesive pads on toes medium-sized; lamellae under the 1 st toe of pes mean 6.9 (6–7); lamellae under the 4 th toe mean 11.3 (10–12); preanal pores 6; expanded subcaudals usually beginning 1–8 verticils behind vent (average about 4). Distinctive pattern of narrow dark bands – one on neck, three on body and one on anterior sacrum, often suffused with yellow in life; tubercles on body often with opaque white pigment, sometimes on medial side of tubercles, while lateral sides are dark. Tail very light distally with pattern of 7–9 widely separated dark bands, the more distal of which extend to the ventral surface.

Distinguished from H. alkiyumii by its smaller adult size (SVL max. 53.6 mm, compared with max. 74.5 mm), fewer preanal pores in males (6, compared with mean 7.3, 6–10), more slender habitus and distinctive coloring of the tail and body. Hemidactylus festivus differs from H. yerburii in its smaller adult size (SVL max. 53.6 mm, compared with max. 67.6 mm in H. yerburii ), in having fewer longitudinal rows of dorsal tubercles at mid-body (mean 13.3, 12–15, compared with mean 16.7, 16–17), fewer preanal pores in males (6, compared with mean 12.8, 10–15), and in having enlarged tubercles on tail that are not spinose. It differs from H. yerburii montanus , endemic to the highlands of Yemen, in its smaller adult size (SVL max. 53.6 mm, compared with max. 68 mm in H. y. montanus ), in having fewer longitudinal rows of dorsal tubercles at mid-body (mean 13.3, 12–15, compared with mean 15.1 in males and 15.47 in females, 14–16), and in having fewer preanal pores in males (6, compared with mean 10.2). It differs from H. jumailiae from Yemen (formerly H. yerburii ) in having large trihedral tubercles present on back (small cycloid tubercles in H. jumailiae ), more slender habitus and distinctive coloring. It differs from H. shihraensis in having higher number of lamellae under the 1 st toe of pes (mean 6.9, 6–7, compared with 6), higher number of lamellae under the 4 th toe of pes (mean 11.3, 10–12, compared with 10). It differs from H. saba in having lower number of lamellae under the 1 st toe of pes (mean 6.9, 6–7 compared with 8), a higher number of ventral scales (about 45 in a transverse row at mid-body between lateral folds where these are discernible, compared with an average of 31 in males and 30 in females in H. saba ).

Etymology

The species epithet “ festivus ” is an adjective that refers to the “happy” aspect of this species, with its bright coloring in the dorsal pattern of living animals and with the juveniles moving around leaping with the tail raised to show its conspicuous black and white coloring.

Genetic and phylogeographic remark

Hemidactylus festivus is monophyletic in the phylogenetic analyses of Dataset 1 ( Fig. 5D) and Dataset 3 (Appendix IIID). The phylogenetic relationships of H. festivus are different in Fig. 5 and Appendix III, as a result of the different taxa included in Datasets 1 and 3. According to Fig. 5, H. festivus is sister to H. sp. 1, although bootstrap and pp support values are very low. However, the phylogenetic tree from Appendix III suggest that H. festivus is sister to H. shihraensis , a species recently described from the Hadramaut, Eastern Yemen ( Busais & Joger 2011a) and also closely related to H. saba from Northwest Yemen and to an undescribed Hemidactylus ( Hemidactylus sp. ) from Western Yemen ( Busais & Joger 2011a). Both phylogenetic trees ( Fig. 5 and Appendix III) support the position of H. festivus between H. robustus and the small Hemidactylus of the H. homoeolepis group ( H. homoeolepis plus the three new species described below belonging to clades E, F and G). The support for this clade in Fig. 5 is very high. The absence of the sister taxa of H. festivus , H. shihraensis , and also of H. saba and H. sp. from Dataset 2 (the dataset used for calibrations), prevents us from commenting on the dates of the possible origin of H. festivus . Uncorrected genetic distances between H. festivus and H. alkiyumii are 14.1% in the cytb and 6.5% in the 12S; between H. festivus and H. y. yerburii 19.4% in the cytb and 10% in the 12S; between H. festivus and H. y. montanus 9.5% in the 12S; between H. festivus and H. jumailiae 10.3% in the 12S; between H. festivus and H. shihraensis 5.3% in the 12S; and between H. festivus and H. saba 8% in the 12S. An individual of H. festivus from the Hadramaut (JS1; see Fig. 1), just 110 km North of the type locality of H. shihraensis (Ghayl Ba Wazir in Google Earth – Ghail Bawazeer in Busais & Joger 2011a), is genetically very similar to the other individuals of H. festivus situated between 430 and 600 km further East and maintains its genetic distinctiveness with the geographically closer H. shihraensis . Despite the relatively large area occupied by H. festivus (more than 850 km in a straight line between specimens JS1 and BMNH1983.706), the level of genetic variability is rather low: 0.4% in the cytb and 0.1% in the 12S, suggesting that H. festivus probably has a continuous distribution between the Hadramaut area in Yemen and Oman. Alternatively, the specimens from Wadi Hadramaut may be the result of a human-meditaed introduction, although we consider this hypothesis very unlikely.

The results of the nuclear networks presented in Fig 7 and a network analysis including all specimens from Dataset 1 (data not shown) indicate that all alleles of H. festivus for all three independent loci analyzed (c -mos, mc1r and rag2) are private (not shared with any other species included in the analyses).

Distribution

Hemidactylus festivus is distributed across 850 km, from the Hadramaut area in Southeastern Yemen to Southern Dhofar province in Oman, as far East as Sawqirah ( Fig. 2). Although it can be found geographically very close to H. alkiyumii (even in sympatry at one locality; see Fig. 2 specimens JS7, JS12 and JS15), H. festivus mainly occupies the dry landward (Northern) side of the mountains, on the other side of the Dhofar Mountains and, in general, much dryer habitats than H. alkiyumii . Interestingly, Hemidactylus festivus is also found in Wadi Mughsayl on the Salalah coast, an area between clades C2 and C3 of H. alkiyumii in which this latter species has never been recorded.

Habits

The species occurs on rock pavements and low down on large boulders. At the type locality, H. festivus is replaced further from the ground by Hemidactylus lemurinus and Ptyodactylus ( Arnold 1980) and newborns and juveniles share the ground with the much smaller H. homoeolepis . Although it occurs in drier habitats than H. alkiyumii , it is not found in really arid situations ( Fig. 19). This species is particularly agile and subadults especially progress in a series of leaps when pursued, with the tail raised to show its conspicuous black and white coloring. Specimens from Wadi Ayoun collected in June were gravid but none had eggs in early October ( Arnold 1980). According to our observations, H. festivus seems a strictly nocturnal gecko, as it has never been observed active during the day.

Description

Up to 53.6 mm SVL. Head and body markedly depressed; head broad, especially posteriorly and neck well defined. Head length about 26–30% of SVL (mean males 28, mean females 27%), head width 63–81% of head length (mean males 71%, mean females 72%), and head height 38–54% of length (mean males 45%, mean females 44%). Adhesive pads quite narrow; in adults the maximum width of pad on fourth hind toe a third to a half its length.

Nostril between rostral, supranasal and two superposed postnasals, with the first supralabial scale usually also entering narrowly into its border. Usually one scale separating supranasals on midline. About 13–15 scales in a straight line from postnasal to edge of orbit. Small conical tubercles scattered in orbital area and on crown of head and often larger on temporal area above the level of ear opening, and immediately in front of the upper part of this. Ear opening often broad inverted comma shape with its longest axis running upwards and backwards, smoothedged, usually less than one third of eye diameter. Supralabial scales mean 9.8 (9–11), infralabials mean 8.4 (7–10). Mental scale broadly triangular, posteriorly bordered by two large postmentals making contact behind it, a second pair of more lateral postmentals also present, all four with a smooth common transverse posterior border; second postmentals contacting the first and second upper labials; third and more posterior lower labials bordered by more irregular and smaller enlarged scales. Gulars fine, rounded with little overlap.

Enlarged tubercles present on back, arranged in obliquely diagonal rows from near midline to flank, mean 13.3 (12–15) across mid-body, and 15–17 in a paravertebral row from the level of the axilla to that of the groin, and largest on upper flank, where they are separated by spaces of about their own length or less. Tubercles keeled, striated and trihedral but becoming smaller and more rounded on lower flanks. Ventral scales small, and flat, but larger than dorsals and imbricate, about 45 in a transverse row at mid body between lateral folds where these are discernible. Males with 6 preanal pores, sometimes separated by one or two scales giving a formula of 3+3. Scales on upper forelimb small and imbricate, interspersed with enlarged tubercles of different sizes on distal section. Scales on front of thigh and beneath about same size as belly scales and imbricate, rather larger under tibia, enlarged tubercles present on upper surface of both femur and tibia and also on posterior edge of foot. Lamellae under the toes of pes: 1 st toe mean 6.9 (6–7), 4 th toe mean 11.3 (10–12).

Tail relatively slender; 6 enlarged, keeled and pointed tubercles on each whorl proximally, dropping to 4 around whorl 8 or 10. Tubercles about half the length of basal whorls, becoming smaller and placed more posteriorly on whorls distally. About 9–10 small scales in longitudinal row on fourth whorl after vent, around five small scales between tubercles on fourth and fifth whorls. Subcaudal scales enlarged and broad, extending proximally as far as whorls 1–7 after the vent (average 4).

In alcohol, often warm pale buff; sometimes a vague darker stripe from the nostril, through the eye and on to cheek above ear; neck and body with narrow darker bands that are convex posteriorly – one on neck, three on body and one on anterior sacrum, bars do not extend on to flanks and may be suffused with yellow in life. Tubercles away from midline with dense white pigment, often the medial surface white and the lateral one darker than background, where scattered dark chromatophores can be seen. Tubercles on limbs and basal tail also white. Belly white, throat limbs and tail pale buff beneath. Underside of adhesive pads on toes pale. Tail becoming much lighter towards tip, with 7–9 widely separated dark bars above, beginning around verticil 8 or 9, each about a whorl long and separated by one or two whorls from the next; bars much shorter than intervening areas; more posterior bars extend to ventral surface. Juveniles like adults but distal tail colouring more contrasting and intense.

Distinctive features of Holotype

Adult female, 49 mm SVL; tail intact 58 mm long; a longitudinal incision present on left side of belly. Supralabial scales 9/10, infralabials 9/9; 14 rows of enlarged tubercles at mid-back; lamellae under the 1 st toe of pes 7/7, 4 th toe of pes 11/11.