Hemidactylus vernayi Ceriaco , Agarwal, Marques and Bauer 2020

Lobon-Rovira, Javier, Conradie, Werner, Iglesias, David Buckley, Ernst, Raffael, Verissimo, Luis, Baptista, Ninda & Pinto, Pedro Vaz, 2021, Between sand, rocks and branches: an integrative taxonomic revision of Angolan Hemidactylus Goldfuss, 1820, with description of four new species, Vertebrate Zoology 71, pp. 465-501 : 465

Hemidactylus vernayi Ceriaco, Agarwal, Marques and Bauer 2020

Figs 6 , 7

Based on both phylogenetic hypothesis (BI and ML), H. vernayi is sister species to H. bayonii , presumably a relic in arid coastal ecosystems (Fig. 2 , Fig. 6C ), and forming a monophyletic group with H. bayonii , H. nzingae , and another species from northern Angola and Cabinda described below. The uncorrected p-distance found within H. vernayi for ND2 was 1.52%. The p-distances for ND2 between H. vernayi and their closely related species were: 14.15% with H. bayonii , 15.55% with H. nzingae , and 14.73% with the northern species described below (see Table 1 ). Small size and other morphological similarities have previously led to a misidentification of this taxon, or to its assignment to H. bayonii , by different authors.

Material examined.

ANGOLA • 2 ♀; Namibe Prov., Santa Marta, Lucira ; -13.87861°, 12.42444°; 48 m a.s.l.; 24 May 2019; Pedro Vaz Pinto; FKH0226-7 and MNCN 50538 • 3 ♂; same collecting data as previous material; FKH0228, MNCN 50539, FKH0232 • 4 ♀, 1 ♂ same collecting data as previous material; 6 Jul. 2019; Pedro Vaz Pinto and Javier Lobón-Rovira; FKH0263-6, MNCN50533 • 1 ♀ juv.; same collecting information as previous material; FKH0268 • 2 ♀; Bentiaba ; -14.17596°, 12.44689°; 150 m a.s.l.; 15 Feb. 2020; Pedro Vaz Pinto and Javier Lobón-Rovira; MNCN 50541 and ZMB 90448 • 2 ♂; same collecting information as previous material; FKH0417 and ZMB 90449 • 3 ♂; Lucira ; September 1956; Charles Koch; TM 24447, 24450-1 • 1 ♂ and 1 ♀; Benguela Prov., Hanha ; -12.24245°, 13.71399°; 39 m a.s.l.; 16 Nov. 2019; Pedro Vaz Pinto; ZMB 90450 -1.

Updated comparative diagnosis.

Hemidactylus vernayi is readily distinguished from non-Angolan congeners by sharing the same distinctive characters as H. bayonii (see Ceríaco et al. 2020a). In respect to the Angolan congeners, H. vernayi differs from H. longicephalus -group in its much smaller maximum size (maximum SVL 42.5 mm [mean=32.67] vs. 60.1 mm [mean=46.57] in H. longicephalus and 64.8 mm [mean=58.96] in H. paivae ); from H. benguellensis by its lower number of precloacal pores (5-7 vs. 23-33); and from H. mabouia by having small subcaudal scales and a lower number of precloacal pores (5-7 vs. 28-39). Hemidactylus vernayi can further be distinguished from H. nzingae by fewer [11-16] rows of weakly keeled dorsal and caudal tubercles (vs. 16-21 rows of strongly keeled dorsal and caudal tubercles in H. nzingae ). Interestingly, morphological analysis based on topotypic material of H. vernayi show extensive overlap with H. bayonii , and no clear diagnostic characters. Nevertheless, when we include the southern specimens of H. vernayi , these reveal a larger number of ventral scales across the belly (33-39 vs. 25-32 in H. bayonii , see Tables S3-4). See other new species descriptions for comparisons with this taxon.

Coloration.

In life (specimen FKH0417; Fig. 6A ): dorsum dark brown with two lighter dorsolateral bands from the nares to the anterior part of the tail; the dorsal region presents a darker crossband from occipital to the medium the region of the tail where it fades before disappearing; the crossband in the dorsal region presents a W-shaped marking common in H. bayonii -group, which becomes V-shaped as it approach the posterior region; the head displays a linear crossband from the eye region to the occipital; all the crossbands along the body are separated by a light beige section; the ventral region has uniform beige coloration; supralabials have dark coloration while infralabials show the same light beige of the ventral region; limbs with irregular dark and light brownish patches; iris golden with a black narrow pupil and dark brown reticulation. Variation (Fig. 7 ): this species presents high variability in coloration from light whitish cream to brownish. Dorsal pattern can be present or absent. Furthermore, it was observed that in some individuals during the day the darker regions become lighter, making it often difficult to differentiate the dorsal pattern, due to a uniform light beige color across the whole body.

Distribution and conservation (Fig. 6C ).

This species is considered the sister species of H. bayonii , so far only known to occur along the arid coast from Bentiaba in northern Namibe Province, northwards to Hanha in coastal Benguela Province (Fig. 6 ). Despite being still poorly known, the species is probably widely distributed, and its habitat does not appear at present to be threatened; however, due to limited number of records we cannot calculate the extent of occurrence (EOO) and thus we regard the conservation status of the species as Data Deficient. Further studies are suggested to better assess its full distribution and conservation status.

Natural history and habitat (Fig. 6B ).

Hemidactylus vernayi is an arid-adapted species, found foraging among small shrubs in arid coastal rocky semi-desert environments on the northern fringes of the Kaokoveld desert, and present also in vegetated valleys cutting through coastal semi-arid savannas. The species occurs along a coastal strip within the Semi-Arid Savanna AMBU, a region strongly influenced by the Namibe fog-belt (Cernak et al. 2012; Vaz Pinto et al. 2019). In the southernmost populations, most specimens were found associated with a recently described endemic small bush Commiphora benguellensis (Swanepoel 2015), while the northern populations were found in thicker and more diverse bush-dominated habitats. This species was always found foraging at night moving with agility between the spiny branches of small to medium-sized bushes, typically close to the ground and dropping quickly to the ground to seek shelter among crevices and cavities, or under small rocks or leaf-litter, when disturbed. Other species of geckos found in sympatry were Chondrodactylus fitzsimonsi , C. pulitzerae and Pachydactylus angolensis . No other Hemidactylus species were found occupying the same ecological niche as H. vernayi .

Figures

Figure 6. A - dorsal view in life of Hemidactylus vernayi (MNCN 50541), B - habitat of H. vernayi, C - updated records of the H. bayonii - group and H. nzingae - group (blue color represents H. bayonii, purple H. vernayi, and green H. nzingae; circles represent genetically confirmed records, while triangles represent historical or non-genetically assigned records based on Ceriaco et al. (2020 a, c); color stars depict the different type localities, black star depicts the original type locality of H. bayonii assigned by Bocage (1893), red star depicts type locality of H. hannahsabinae by Ceriaco et al. 2020. Photos by Javier Lobon-Rovira (A-B).

Figure 7. Dorsal photographs showing morphological variability found in Hemidactylus vernayi from (A) Hanha (ZMB 90450), (B) Bentiaba (MNCN 50541) and (C) Santa Marta (MNCN 50533). Photos by Pedro Vaz Pinto (A) and Javier Lobon-Rovira (B, C).

Figure 2 A. Bayesian Inference (BI) phylogenetic tree based on ND 2 + RAG 1 concatenated data, with Maximum Likelihood (ML) support overlaid. Numbers above the key nodes indicates BI posterior probability (≥ 0.90 were considered supported), while below the key nodes indicate ML bootstrap values (≥ 75 % were considered supported). Major clades are marked with a thick vertical line.