Microgecko varaviensis, Gholamifard & Rastegar-Pouyani & Rastegar-Pouyani, 2019

Gholamifard, Ali, Rastegar-Pouyani, Nasrullah & Rastegar-Pouyani, Eskandar, 2019, A new species of the genus Microgecko Nikolsky, 1907 (Sauria: Gekkonidae) from the southern Zagros Mountains, Iran, Zootaxa 4648 (3), pp. 435-454 : 440-451

publication ID	https://doi.org/ 10.11646/zootaxa.4648.3.2
publication LSID	lsid:zoobank.org:pub:3B46DDF7-7ECD-4791-8465-9B99A65561F7
persistent identifier	https://treatment.plazi.org/id/064687DA-670B-FFCA-4D82-F99FFBA3A15F
treatment provided by	Plazi
scientific name	Microgecko varaviensis
status	sp. nov.

Treatment

Microgecko varaviensis sp. nov.

( Figs. 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4 , 8d View FIGURE 8 , 9b View FIGURE 9 , 10a View FIGURE 10 )

Microgecko helenae helenae— Gholamifard & Rastegar-Pouyani, 2015

Holotype. RUZM GT.11.57, collected at Varavi Mountain , 27°30’27.4’’ N, 53°07’10.8’’ E and 1340 m a.s.l., Varavi District, Mohr County, southwest Fars Province, southern Iran, on 3 September 2013 at about 03h10 by A. Gholamifard. GoogleMaps

Paratypes. RUZM GT.11.58–63, GT.11.111–112 (n=8), collected at the same locality as the holotype on 3 September 2013 from about 03h10 to 07h00 by A. Gholamifard and local field assistants GoogleMaps .

Other topotypical material. RUZM GT.11.73–75 (n=3), collected at the same locality as the holotype and paratypes in the Varavi Mountain on 1 April 2015 from about 10h00 to 18h00 by A. Gholamifard and local field assistants GoogleMaps .

Diagnosis. Microgecko varaviensis sp. nov. ( Figs. 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4 ) is a small gecko with a maximum known snout-vent length ( SVL) of 28.3 mm. The species possesses all diagnostic characters of the genus Microgecko (sensu Bauer et al. 2013). Microgecko varaviensis sp. nov. has a dorsum without any distinct or indistinct crossbars, with light white spots ( Figs. 2–3 View FIGURE 2 View FIGURE 3 ); and the regenerated portion of tail in M. varaviensis sp. nov. is yellow to brownish-yellow ( Fig. 2 View FIGURE 2 ). In the new species four scales border the nostril ( SBN) instead of five ( Fig. 9 View FIGURE 9 ); the number of ventral scales from behind the postmentals to a level of vent ( GVA) is 101–114; the range of dorsal scales in midline between axilla to groin ( AGS) is 56–71; and the supranasals (internasals) are separated by two granular scales ( Fig. 10a View FIGURE 10 ). Microgecko varaviensis sp. nov. has 6–7 (mean 6.27) supraliabial and 5–6 (mean 5.73) infralabial scales.

Comparisons. Superficially, M. varaviensis sp. nov. differs from M. h. helenae , M. h. fasciatus, M. latifi , and M. persicus (all three subspecies) by having a dorsum without any distinct or indistinct crossbars, and from M. chabaharensis and western populations of M. cf. helenae (which lack cross bands) by the presence of light white spots ( Figs. 2–3 View FIGURE 2 View FIGURE 3 ). Also, the regenerated portion of tail in M. helenae populations is uniform black ( Fig. 6 View FIGURE 6 ).

Microgecko varaviensis sp. nov. has a single pair of postmental shields and, therefore, differs from M. latifi (no postmentals), M. depressus (no postmentals or only one pair of very small postmentals), M. persicus (two pairs of postmentals) and M. chabaharensis (three pairs of postmentals) ( Fig. 8 View FIGURE 8 ). Microgecko varaviensis sp. nov. differs from M. helenae (M. h. helenae and M. h. fasciatus) with which it shares one pair of postmental shields, in having a lower range of GVA (101–114) versus 106–123 and 111–130, respectively, in M. h. helenae and M. h. fasciatus. AGS in M. varaviensis sp. nov. is 56–71 versus 63–82 in M. h. helenae and 82–96 in M. h. fasciatus. Also, Microgecko varaviensis sp. nov. differs from M. chabaharensis , and M. p. persicus by having the lower number of supraliabial (6–7) and infralabial (5–6) scales, as compared with M. chabaharensis and M. p. persicus with 8–9 and 8, and 9–10 and 7–9, respectively ( Szczerbak & Golubev 1986). For additional comparisons see Tables 1 View TABLE 1 and 2 View TABLE 2 .

The distinctive morphological features of the above mentioned specimens from Fars Province among all populations of Microgecko with a single pair of the postmental shields, e.g. the lack of dorsal crossbars, white spots on the dorsum, different color of the regenerated tail, lower number of ventral scales ( GVA) and scales that border nostril ( SBN), the complete separation of both pairs of internasals ( SSIN) and post internasals ( SSPIN) (see Tables 1 View TABLE 1 and 2 View TABLE 2 ; Figs. 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4 , 6–10 View FIGURE 6 View FIGURE 7 View FIGURE 8 View FIGURE 9 View FIGURE 10 ), as well as differences of its habitats in the southern Zagros Mountains from M. helenae in southwest and western Iran, as well as a high uncorrected genetic distance (cytochrome b) of 15.7% between M. h. helenae and M. varaviensis sp. nov. strongly support M. varaviensis as a new species.

Description of the Holotype ( Figs. 2 View FIGURE 2 , 9b View FIGURE 9 , 10a View FIGURE 10 ). An adult female with intact tail; SVL 23.64 mm; TL 24.75 mm; tail cylindrical, tapering evenly to its tip; head stout with distinct eyes, HL 4.7 mm; HH 2.57 mm; HW 4.52 mm; ED 1.47 mm; EO 0.2 mm; NED 1.31 mm; EED 2.24 mm; IOD 2.81 mm; neck distinct, a prominent pair of endolymphatic sacs in the neck region; LFL 8.06 mm; LHL 10.58 mm; TrL 9.32 mm; rostral pentagonal, broader than high, divided by a median cleft, bordered by first supralabials, nostrils, two postrostrals, and the anterior granular scale between the postrostrals; nostril on each side surrounded by four scales ( SBN), including rostral, first supralabial, enlarged postrostral, and one nasal scale ( Fig. 9b View FIGURE 9 ), nostrils separated by two large postrostrals (internasals or supranasals); enlarged postrostrals are separated by two granular scales, anterior granular scales bordering posterior of rostral, postrostrals followed by an additional pair of enlarged scales (post internasals), this second pair of enlarged scales is distinctly smaller than postrostrals, and separated by two granular scales; three granular scales separate both pairs of internasals and post internasals ( Fig. 10a View FIGURE 10 ); snout covered with small juxtaposed granules distinctly larger than those on crown and upper sides of head and occiput; granules on sides of snout somewhat larger than those on midline; IOS 20, 6 supralabials on each side, posterior labials distinctly larger than succeeding small gran- ules; 5 infralabials on each side; mental nearly pentagonal, bordered by first infralabials, a single pair of postmental shields, and a granular scale, extending posteriorly to the middle level of the first infralabials, not sharply pointed behind, slightly broader than long, followed by one pair of large nearly trapezoidal postmentals, which are separated by one distinct granular scale, distinctly smaller than first infralabial, connected with mental, the first lower labials, and five granular scales in posterior; SBIL 9; SCIL 2; scales of chin and throat granular and juxtaposed. Dorsum covered with equal, smooth, juxtaposed small scales; scales of venter smooth, flat, imbricate, larger than those of dorsum; scales of upper surfaces of limbs slightly larger than those of dorsum, scales of lower surfaces of limbs like those of venter, slightly smaller; no femoral or precloacal pores.

Tail covered above and below with smooth scales, slightly imbricate, distinctly larger than those of dorsum and venter, arranged in regular transverse series, 11 dark crossbars on tail (terminal dark point of tail was also counted), as with their light margins wider than yellow interspaces, bordered posteriorly with whitish in the first anterior dark band and yellow in other bands, each dark band gradually becomes darker from light brown to medium brown from front to back ( Fig. 2 View FIGURE 2 ), two enlarged scales on outer side of each pore at base of tail just posterior to level of vent; digits covered above with smooth, small juxtaposed scales, below with single series of smooth lamellae, 14 under fourth toe, toe somewhat angularly bent; GVA 108; AGS 68.

Coloration of live specimens. Coloration of the living holotype ( RUZM GT.11.57) is almost exactly the same as the paratypes and topotypes, but the larger specimens have wider dark crossbars on their tail. The upper body surface of the holotype, pararypes and topotypes is uniformly pinkish with two dorsolateral series of white spots, the first pair of which are more distinct ( Figs. 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4 ). This is in contrast to the distinct or indistinct dark dorsal crossbars ( Figs. 6–7 View FIGURE 6 View FIGURE 7 ) present in M. helenae , M. latifi and M. persicus ( Anderson 1999) . A wide dark or chocolate-brown bar on either side runs from behind the rostral, through the eye and ear opening to behind the forelimbs; the lower surfaces of the head and trunk are whitish; the lower surface of tail is yellow; the regenerated portion of the autotomized tail is yellow to brownish yellow ( Fig. 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4 ).

Paratypes. The paratypes do not differ significantly from the holotype regarding scalation, coloration and pattern, with the exception of minor differences in some meristic characters. The range of meristic characters on each side (R/L) for RUZM GT .11.58–63, GT.11.111–112 (n=8) follow: one pair of postmental shields ( PMP); SL 6–7/6–7; IL 5–6/5–6; SSPM 1–2; SCIL 1–3/1–3; SBIL 9–11; IOS 20–25; SBN 4/4; SSIN 2; SSPIN 2; SBNL 11–13/11–12; SubL 4 th 13–14 (left pes); GVA 101–114; AGS 59–71; none dorsal crossbars from forelimbs region to the sacral region ( DC), TC 9.

The range of metric characters for the subadult and adult paratypes ( RUZM GT.11.58–63, GT.11.111–112) are as follows: SVL 12.98–28.34 mm; TL 8.91–23.12 mm; HL 4.2–7.64 mm; HH 2.51–3.98 mm; HW 3.2–5.13 mm; ED 1.06–1.58 mm; EO 0.17–0.48 mm; NED 1.29–2.42 mm; EED 1.65–3.11 mm; IOD 2.11–2.75 mm; LFL 4.73–9.35 mm (left side); LHL 5.17–13.54 mm (left side); TrL 5.77–14.84 mm.

Topotypes. The topotypes ( RUZM GT.11.73–75) do not differ significantly from the holotype and paratypes regarding scalation, coloration and pattern.

Genetic results. The cytochrome b dataset comprised 752 aligned sites, of which 379 were constant, while 59 variable characters were parsimony-uninformative and 314 were parsimony informative. Uncorrected p-distances for the cytochrome b gene of the Microgecko populations of this study are presented in Table 4 View TABLE 4 . The mean genetic divergences of M. varaviensis sp. nov. from M. h. helenae and M. chabaharensis are 15.7% and 19.3%, respectively. The genetic divergence of the new species from M. h. fasciatus is 20.5%. Interestingly, the genetic divergence between M. h. helenae and M. h. fasciatus is 18.9% ( Table 4 View TABLE 4 ).

The ML, MP and BI trees resulted in nearly identical topology (only the Bayesian tree is shown in Fig. 11 View FIGURE 11 ). Microgecko varaviensis sp. nov. formed a monophyletic group with strong support. Subclades from the southwest portion of Fars Province (type locality at Varavi Mountain) and central Fars Province (Jahrom and Firuzabad) also have high posterior probability values (1.00) in the BI analysis. Microgecko helenae helenae specimens from Khuzestan Province (Bid Zard and Baghe Malek) formed a monophyletic group with strong support, as the sister taxon of M. varaviensis sp. nov., whereas all samples of M. h. fasciatus from Kermanshah (Sorkheh Dizeh, Shelean, Patagh, Mela Har, Saymareh) and Ilam (Karezan) provinces formed a distinct monophyletic group with strong sup- port, which in turn contains two main subclades: northern populations (Sorkheh Dizeh, Shelean, Patagh in Kerman- shah Province; subclade A) and southern populations (Ilam Province and adjacent area; subclade B). Microgecko h. fasciatus is sister to a more inclusive clade including M. h. helenae and M. varaviensis sp. nov. Among the present taxa in the genus, M. chabaharensis (Fars, and Sistan and Baluchestan provinces) is sister to all other taxa. In this clade, a specimen from Fars Province (Rezuiyeh) shows distinct divergence, and further study of this population is needed ( Fig. 11 View FIGURE 11 ).

Etymology. The species is named after the region where the type material was collected (Varavi Mountain, Varavi District, Fars Province, southern Iran).

Habitat. The type locality of M. varaviensis sp. nov. is in a mountainous area (Varavi Mountain) in the southern parts of the Zagros Mountains, about 45 km from the Persian Gulf ( Figs. 1 View FIGURE 1 , 5 View FIGURE 5 ). Varavi Mountain is a long massif with a length of 124 km and width of 4–8 km and extends from the western border of the Mohr Township to the eastern border of Lamerd Township, both in the southwest of Fars Province. It is parallel with the southern limit of the Zagros Mountains in Bushehr and Hormozgan Provinces ( Fig. 5a View FIGURE 5 ). The vegetation of the type locality consists of different species of thorny bushes ( Astragalus ), seasonal herbaceous cover, thin growth of wild Ziziphus trees, and sparse wild almond trees Amygdalus scoparia Spach , wild pistachio (common name in Persian is Baneh) Pistacia atlantica Desfontaines , and wild fig Ficus sp. ( Fig. 5b View FIGURE 5 ). Woody elements of the vegetation are more abundant at higher elevations and in intact areas of Varavi Mountain.

Ecological notes. Microgecko varaviensis sp. nov., is nocturnal and is one of the smallest recorded lizards of Iran. It appears to be sensitive to temperature changes. The holotype and all paratypes of M. varaviensis sp. nov. were inactive at night and were hidden under large stones, with fairly firm connection to the ground, especially along a dry stream bed, while the first author searched for the gecko on the surface due to its nocturnal activity, especially in the last month of summer in southern Iran. Other specimens (topotypes) were found under large stones with a relatively tight connection with the ground during a spring day (1 April 2015). In most cases of the gecko collection, under the stones of their shelter was moist. Based on our finding, this gecko uses of large stones as a shelter against adverse environmental conditions during periods of inactivity or hibernation. The first author collected a specimen of M. varaviensis sp. nov. under a relatively large stone with a scorpion, in January 2017 at about 10h00 at a temperature of approximately 9 C° at the type locality. The forested habitat of M. varaviensis sp. nov. on the hillsides of the Zagros Mountains in Firuzabad County (west of Fars Province) is covered with dominant trees of P. atlantica , A. scoparia , several species of thorny bushes and herbaceous cover.A subadult specimen from this habitat was collected at 08h10 from under a relatively large stone with partly firm contact to the ground in a dry bed of a water course in a shaded area near wild pistachio and bushes.

The regenerated part of tail in specimens of both subspecies of M. helenae (from western and southwestern Iran) is black, whereas in M. varaviensis sp. nov. (from southern Iran) the regenerate is uniformly yellow to brownish-yellow (see Fig. 2 View FIGURE 2 versus Fig. 6 View FIGURE 6 ). It is probable that this color difference in different populations of Microgecko has an ecological function, namely camouflage in the environment, whereas the black tail would make the gecko more visible to its natural enemies in sparse ground vegetation in the south of Fars Province. Specimens of the new species kept in captivity for several months and fed with small arthropods, especially spiders, show no change in coloration of the regenerated portion of the tail.

Some sympatric and/or syntopic species of reptiles in the vicinity of the type locality are: Laudakia nupta (De Filippi) , Hemidactylus persicus Anderson , Pristurus rupestris Blanford , Walterinnesia morgani (Mocquard) , Pseudocerastes persicus (Duméril, Bibron & Duméril) and Macrovipera lebetina (Linnaeus) .