SMF 8723 (lectotype, adult male), Petr. Arabica [Arabia petraea], collected by E. Rüppell in 1827 (MorphoBank M305565–M305594); NMP6V 70163/1 (adult female, MorphoBank M305520–M305528), NMP6V 70163/2 (adult male, MorphoBank M305529–M305542), NMP6V 70163/3–4 (adult females, MorphoBank M305543–M305554, M305555–M305564), Egypt, South Sinai governorate, Sharm el-Sheikh (27.885°N, 34.317°E), ca. 30 m a.s.l., collected by R. Kovář and R. Víta in 1996; ZFMK 94084, ZFMK 94085 (adult females, MorphoBank M305744–M305760, M305761–M305775), Saudi Arabia, Tabuk province, Al Wajh (26.2076°N, 36.4976°E), 5 m a.s.l., 31. V. 2012; ZFMK 94086 (adult female, MorphoBank M305778–M305791), ZFMK 94088, ZFMK 94089 (adult males, M305793–M305799, M305807, M305822–M305827, M305828–M305841), Saudi Arabia, Tabuk province, 15 km S of Al Wajh (26.1226°N, 36.5689°E), 25 m a.s.l., 31. V. 2012; TUZC-R10 (adult female, MorphoBank M305728–M305743), Saudi Arabia, Hail province, 180 km N of Hail (26.8831°N, 40.0874°E), 1020 m a.s.l., 30. V. 2012; IBES10183, TUZC-R11 (adult males, MorphoBank M305656–M305671, M305688–M305701), ZFMK 94090,IBES10344 (adult females, MorphoBank M305672–M305687, M305702–M305717), Saudi Arabia, Makkah province, 30 km NE of Alhawiyah (21.6244°N, 40.7094°E), 1295 m a.s.l., 28. V. 2012; IBES10150, IBES10363 (adult males, MorphoBank M305615–M305628, M305643–M305655), ZFMK 94091 (adult female, MorphoBank M305629–M305642), Saudi Arabia, Makkah province, 20 km S of Ashayrah (21.6022°N, 40.6911°E), 1316 m a.s.l., 28. V. 2012. All Saudi specimens were collected by M. Shobrak, S. Carranza and T. Wilms.

SMB 10660, Egypt, Suez governorate, Ayoun Musa (29.875°N, 32.649°E), ca. 12 m a.s.l., collected by S. Baha El Din, date unknown; TUZC-R9, Saudi Arabia, Tabuk province, 72 km N of Umluj (25.614°N, 36.9867°E), 19 m a.s.l., 31. V. 2012; IBES10001, Saudi Arabia, Riyadh province, Al Ghat (26.0545°N, 45.0003°E), 776 m a.s.l., 29. V. 2012; ZFMK 94087, TUZC-R8, Saudi Arabia, Tabuk province, 15 km S of Al Wajh (26.1226°N, 36.5689°E), 25 m a.s.l., 31. V. 2012; ZFMK 87236, Saudi Arabia, Makkah province, Taif National Wildlife Research Center (21.25°N, 40.96°E), 25. VI. 2007 by T. Wilms. These specimens were used for the molecular analyses only.

Heyden (1827) described Hemidactylus granosus as a new species occurring in Egypt, Arabia and Abyssinia (Ethiopia and Eritrea). Although not explicitly mentioned by the author, the description was apparently based on four specimens collected by Rüppell currently deposited in the Senckenberg Naturmuseum Frankfurt (collection numbers SMF 8723–8726). Heyden did not diagnose the new species against Hemidactylus turcicus (Linnaeus, 1758) and in respect to our today’s knowledge on the morphological variation in Hemidactylus the description of Hemidactylus granosus is very general. Traditionally, Hemidactylus turcicus has been considered a common species widely distributed across the Mediterranean and the Middle East. As the general diagnostic characters of Hemidactylus granosus given by Heyden (1827) were also applicable to Hemidactylus turcicus at that time, the name Hemidactylus granosus Heyden, 1827 was considered its junior synonym (e.g. Boulenger 1885, Loveridge 1947, Mertens and Wermuth 1960, Mertens 1967, Salvador 1981, Baha El Din 2006).

Recent examination (by JŠ) of four specimens collected by Rüppell (SMF 8723–8726) has shown that one of them [SMF 8723 designated by Mertens (1967) as lectotype of Hemidactylus granosus; for description see below] corresponds morphologically to Hemidactylus sp. 1 from Sinai. The other three specimens from this series morphologically correspond to Hemidactylus robustus Heyden, 1827 (SMF 8725, 8726) and Hemidactylus cf. granosus (SMF 8724), an animal superficially resembling Hemidactylus granosus but differing from the members of the ‘Hemidactylus saba species group’ in several important characters (see below). These findings lead to the conclusion that Hemidactylus granosus Heyden, 1827 is a valid taxon and needs to be resurrected from the synonymy of Hemidactylus turcicus. In the light of current knowledge, the range of Hemidactylus turcicus does not include a large part of Egypt, being restricted mostly to northern Egypt including Sinai and its Red Sea coast. The species is also missing in Arabia (sensu lato) and Ethiopia (Carranza and Arnold 2006; Moravec et al. 2011; Rato et al. 2011; Šmíd et al. 2013).

Hemidactylus granosus is a member of the ‘Hemidactylus saba species group’ within the Arabian radiation of the Arid clade as evidenced by the mtDNA and nDNA analyses. The species has the following combination of molecular and morphological characters: (1) Uncorrected genetic distance from Hemidactylus saba: 9.9–10.2% in 12S, 14.5–15.5% in cytb; from Hemidactylus sp. 4: 10.2–12.3% in 12S, 11.2–13.5% in cytb; (2) small size, SVL 39.0–53.2 mm in males, 40.6–53.3 mm in females; (3) rather elongated head, head length 24–28% of SVL, head width 68–86% of head length, head depth 33–47% of head length; (4) tail length 107–130% of SVL; (5) uppermost nasals separated by a small shield in 89% of specimens; (6) large anterior postmentals in wide mutual contact, and always in contact with the 1^st and 2^nd lower labial; (7) 9–11 upper labials; (8) 7–9 lower labials; (9) 14–15 longitudinal rows of enlarged, subtriangular, distinctly keeled dorsal tubercles; (10) 7–8 lamellae under the 1^st toe and 10–13 under the 4^th toe; (11) ca. 6–8 tail segments bearing 6 pointed tubercles; (12) 4–7 preanal pores in males forming a continuous row on the left and right side; (13) subcaudals enlarged; (14) in life, dorsum pale buff with dark brown spots tending to form transverse bands or X-shaped markings, dark horizontal stripe in prefrontal and temporal region, tail with ca. 10–13 dark brown transverse bands, venter white.

SMF 8723, adult male [erroneously determined as female by Mertens (1967)]. Head and body moderately depressed (Fig. 4). Upper labials (10/10), lower labials (8/7). Nostril between rostral, three subequal nasals and in punctual contact with first upper labial. Uppermost nasals separated by a small inserted scale. Mental triangular, as long as wide. Anterior postmentals long, in a broad contact with each other, both in contact with the 1^st and 2^nd lower labial reaching in about one fourth of the width of the 2^nd labial. Second postmentals almost round, touching only the 2^nd lower labial (Fig. 5). Two enlarged scales behind each second postmental, the lateral ones in contact with the 3^rd lower labial. Eye moderate (E/HL=0.26). Head long, distinctly separated from body by a slender neck. Crescent-shaped ear opening. Interorbital region, crown of head and temporal area above the level of ear opening covered by round smooth tubercles. Dorsal region of the specimen is slightly scarred so it is not possible to count the enlarged tubercles on both sides precisely, but there are seven longitudinal rows of large, keeled and caudally pointed tubercles on the left side from which we infer there were originally 14 rows on both sides together. Lower arms, thighs and lower legs with prominent tubercles without keels. Tail original with 6 segments bearing 6 pointed tubercles, broken into three pieces, subcaudals enlarged from just after the hemipenial bulges. Lamellae under the 1^st toe 7/7, lamellae under the 4^th toe 11/11. Four preanal pores in a continuous row. No femoral pores or enlarged femoral scales. Colour (in alcohol) faded due to long fixation.

Measurements (in mm): SVL 51.5, HL 12.9, HW 9.8, HD 6.0, E 3.3, AG 23.7.

Paralectotype SMF 8724 differs from other individuals of Hemidactylus granosus in having relatively high head (HD 50% of HL), lower number of lower labials (6), uppermost nasals in wide contact, first postmentals in contact with 1^st lower labials, and 2 preanal pores.

Hemidactylus granosus can be distinguished from other member of the ‘Hemidactylus saba species group’ and from other congeners distributed in Sinai and the Red Sea coast by the following set of characters (see also Table 2).

From Hemidactylus saba by having distinctly keeled dorsal tubercles (smooth in Hemidactylus saba), and lower number of lamellae under the 1^st toe (7–8 vs. 8–9).

From Hemidactylus sp. 4 (described below) by its larger size (max. SVL 53.2 mm vs. 40.4 mm in males, 53.3 mm vs. 40.7 mm in females), in having more frequently separated uppermost nasals (100% vs. 60% of specimens), lower number of preanal pores in males (4–7 vs. 8), and higher number of lamellae under the 1^st (7–8 vs. 5–6) and 4^th (10–13 vs. 8–9) toe.

From Hemidactylus flaviviridis by its smaller size (max. SVL 53.2 mm in males and 53.3 mm in females vs. up to 90 mm [Anderson (1999); sexes not distinguished]), by the presence of enlarged dorsal tubercles, and the absence of femoral pores in males.

From Hemidactylus mindiae by the lower number of supralabials (9–11 vs. 10–12), by having anterior postmentals in wide contact (punctual in Hemidactylus mindiae) and keeled dorsal tubercles (smooth in Hemidactylus mindiae).

From Hemidactylus robustus by the larger size of males (max. SVL 53.2 mm vs. 43.7 mm), longer tail (tail length 53.0–64.8 mm vs. 40.9–48.7 mm), and lower number of preanal pores in males (4–7 vs. 5–8).

From Hemidactylus turcicus by its higher number of upper labials (9–11 vs. 7–10), in having anterior postmentals more frequently in contact with 2^nd lower labial (100% vs. 12.1%), in having anterior postmentals in wide mutual contact behind the mental scale (contact punctual in 67% specimens of Hemidactylus turcicus), and by the lower number of preanal pores in males (4–7 vs. 6–10).

Specimens with intact tail vary in number of tail segments bearing 6 pointed tubercles (7–8). The original portion of the tail of the female NMP6V 70163/4 is very wide at the base, separated from cloacal region by a basal constriction. One specimen (IBES10212) is the only animal with 15 longitudinal rows of enlarged tubercles. Another one (IBES10284) has uppermost nasals in wide contact. Most striking is the variation in the number of preanal pores in males. Whereas the lectotype and the only male from Sinai (NMP6V 70163/2) have both 4 pores, all males from Saudi Arabia have 6–7 pores. There seems to be clinal variability in this character, males from NW of the known range (Fig. 6) possess only 4 preanal pores, all animals from the eastern Red Sea coast in Saudi Arabia have 6 pores and a single individual from the southern limit of the range has 7 pores.

Coloration (in life) pale buff dorsally (Fig. 7). Conspicuous dark brown horizontal stripe in loreal and temporal area, terminated at the level of ear from where it continues in a series of dark patches on the neck. Four barely visible X-shaped markings on dorsum formed mainly by dark brown enlarged tubercles (first on nape, second across scapulae, third in lumbal region, and fourth just in front of the anterior insertion of hind limbs). Isolated dark brown stripe runs across body in the place of posterior insertion of hind limbs. Regenerated tails are uniformly buff from above. Dorsum, sides of chin, underside of front and hind limbs and underside of tail with faint stipple visible under magnification. Belly white. Tips of fingers and toes black behind insertion of terminal phalanges. Coloration is consistent among all specimens and varies only in distinctness of the markings.

There is a very low variation in mtDNA between specimens from Sinai and Saudi Arabia (max. 1.3% in both 12S and cytb). All animals from Sinai share the same haplotypes in 12S and also cytb gene. All four nuclear loci studied show some degree of intraspecific variation (Fig. 3).

Eduard Rüppell collected the original series in 1827 when he began his marine biological studies of the Red Sea and travelled from Egypt to Eritrea. There is no specific information that he went to Arabia as well (Rüppell 1826–1828; Klausewitz 2002; Wagner 2008); therefore the original distribution of Hemidactylus granosus described as “Egypt, Arabia, and Abyssinia [Ethiopia and Eritrea]” by Heyden (1827) was probably too general and incorrect. Because there were no other specimens assignable with certainty to Hemidactylus granosus apart from the four individuals collected in Sinai (SMF 8723–8726, for their current status see ‘Status and nomenclature’ section) (Boettger 1893), one of which became the lectotype after Mertens’ (1967) designation, Sinai could be considered the only reliable locality for Hemidactylus granosus. Here, Hemidactylus granosus is also confirmed from two coastal localities in south and west Sinai and from coastal and inland regions in western and central Saudi Arabia (Fig. 6). Nevertheless, a wider distribution of the species along the Red Sea coast can be expected. According to Baha El Din (2005), Hemidactylus geckos inhabiting the interior lowland of Sinai and the Eastern Desert in Egypt stand out in having notably coarse scalation. Interestingly, the areas with occurrence of animals with coarse scalation correspond with the presence of individuals with low numbers of preanal pores (Baha El Din 2005), which is typical for the Sinai populations of Hemidactylus granosus.

In 1996, when the NMP specimens were collected, the locality in Sharm el-Sheikh was formed by a crop field supplied with drain water from nearby habitations. Geckos were found during the day under unused empty barrels and also inside buildings. Other species syntopic with Hemidactylus granosus in Sharm el-Sheikh were: Hemidactylus turcicus, Chalcides ocellatus (Forskål, 1775), Stenodactylus sthenodactylus (Lichtenstein, 1823), and Ptyodactylus hasselquistii (Donndorff, 1798) (R. Víta in litt, 2013). However, when visited again in 2010, the locality had changed dramatically (R. Víta in litt, 2013). The whole area was under heavy development and the irrigation channels had disappeared. The current conditions at the place are unknown to us. In 2011 JM surveyed a neighbouring urban area east of this locality. It was covered by a mosaic of tourist resorts and abandoned ruderal plots. In dry anthropogenic habitats (e.g. rubbish dumps, road ditches, old walls and buildings, abandoned construction sites, natural but heavily disturbed open areas, etc.) dominated two very abundant gecko species. Ptyodactylus hasselquistii occupied primarily various vertical surfaces whereas Cyrtopodion scabrum (Heyden, 1827) prevailed on the ground. Tropiocolotes nattereri Steindachner, 1901 was found in dry and relatively well-preserved natural places. Hemidactylus turcicus was occasionally encountered in more humid artificial habitats in parks and hotel gardens. Specimens from Saudi Arabia were mostly collected during the day inside concrete tunnels under roads. In some of the tunnels they were syntopic with Ptyodactylus hasselquistii. One specimen was also collected on the walls of the Taif National Wildlife Research Centre, where it was also syntopic with Ptyodactylus hasselquistii.