Pachydactylus maiatoi, Marques & Parrinha & Ceríaco & Brennan & Heinicke & Bauer, 2023

Marques, Mariana P., Parrinha, Diogo, Ceriaco, Luis M. P., Brennan, Ian G., Heinicke, Matthew P. & Bauer, Aaron M., 2023, A new species of thick-toed gecko (Pachydactylus) from Serra da Neve and surrounding rocky areas of southwestern Angola (Squamata: Gekkonidae), Vertebrate Zoology 73, pp. 325-343 : 325

Pachydactylus maiatoi sp. nov.

Figs 5 , 6 , 7 , 8 , 9

Pachydactylus angolensis - Ceríaco et al. (2016: 25)

Pachydactylus angolensis "inland form" - Branch et al. (2017: 164)

Pachydactylus angolensis [partim] - Marques et al. (2018: 192)

Holotype.

An adult male (CAS 266485, field no. AMB 10345), collected in N’Dolondolo [-13.8133°, 13.1362°, 681 m a.s.l.], Namibe Province, Angola, by Luis M.P. Ceríaco, Suzana A. Bandeira, and Ishan Agarwal on 22 November 2016.

Paratypes.

Six specimens: one adult male (CAS 254887, field no. JVV 8564), collected in Namibe-Lubango rd, 2 km E of Mangueiras [-15.0436°, 13.1600°, 625 m a.s.l.], Namibe Province, Angola, by Luis M.P. Ceríaco, Hilária Valério, Suzana A. Bandeira, Sango de Sá, Arianna L. Kuhn, Edward L. Stanley, and Jens V. Vindum on 5 December 2013; one adult female (CAS 266484, field no. AMB 10284) with the same data as the holotype; one juvenile (CAS 266486, field no. AMB 10216) collected in Serra da Neve, base camp [-13.7770°, 13.2591°, 1488 m a.s.l.], Namibe Province, Angola, by Luis M.P. Ceríaco, Suzana A. Bandeira, and Ishan Agarwal on 18 November 2016; one adult male (CAS 264256, field no. AMB 11349) collected in Maungo [-14.5383°, 12.7474°, 363 m a.s.l.], Namibe Province, Angola, by Mariana P. Marques, Luis M.P. Ceríaco and Joyce M. Janota on 7 August 2018; one adult male (CAS 264267, field no. AMB 11402) collected in Maungo, abandoned health post [-14.5397°, 12.7447°, 368 m a.s.l.], Namibe Province, Angola, by Mariana P. Marques, Luis M.P. Ceríaco and Joyce M. Janota on 9 August 2018; one adult male (MUHNAC/MB03-001246, field no. LMPC 1182) collected in Serra da Neve, Maylowe village [-13.8355°, 13.2755°, 798 m a.s.l.], Namibe Province, Angola, by Mariana P. Marques, Luis M.P. Ceríaco, and Joyce M. Janota on 26 February 2019.

Additional material.

Namibe Province: Serra da Neve, rocky area near Catchi village [-13.7642°, 13.2573°, 1614 m a.s.l.] (MUHNAC/MB03-001247); Serra da Neve base, 2 km N of Maylowe [-13.8280°, 13.2625°, 820 m a.sl.] (MUHNAC/MB03-001248); Lungo [-14.3167°, 13.2000°, 749 m a.s.l.] (imprecise locality) (TM 24406).

Diagnosis.

A small, rupiculous Pachydactylus with a depressed body form. SVL at least 40.5 mm (Table 3 , 4 ). Dorsum with enlarged, keeled dorsal scales. OrbD slightly greater than EyeEar. Rostral and supralabials excluded from the nostril rim. Lack of contact between the nostril and both the first supralabial and rostral. Tail indistinctly segmented with juxtaposed to subimbricate scalation. Dorsal pattern almost uniform beige to dark brown, sometimes with small and very diffuse whitish spots, with a dark mask in the lateral side of the head terminating above or just anterior to the ear. Labials white. Venter cream with brown spots on limbs and tail. Tail lighter than the dorsum. Forelimbs and hindlimbs moderately short and stout, interdigital webbing absent, free digits with four (4) subdigital, undivided lamellae.

Comparison with other Pachydactylus species. From other members of the "northwestern clade" of Pachydactylus (fide Heinicke et al. 2017) it may be easily differentiated from P. bicolor , P. maraisi , P. punctatus , P. scherzi , and P. caraculicus by its enlarged, keeled dorsal scales (versus atuberculate or smooth scales in the latter). It can be differentiated from most other member of the northwestern group ( P. scutatus , P. parascutatus , P. boehmei , P. gaiasensis , P. oreophilus , P. sansteynae ) by the lack of contact between the nostril and both the first supralabial and the rostral (in contact in all the latter). It can be distinguished from P. otaviensis , endemic to the Otavi highlands in Namibia, by not having the first supralabial in contact with the nostril (versus in contact in P. otaviensis ) and by having a homogeneous cream to brown dorsal coloration pattern (versus consisting of three pale bands on the nape, just posterior to adpressed elbow, and posterior trunk, anterior to lumbar region in P. otaviensis ). Regarding its sister species, P. angolensis , the newly described species consistently differs in terms of its coloration, with P. angolensis presenting scattered large white spots and orange blotches in its light brown dorsum, while in P. maiatoi sp. nov. the dorsum is generally homogenously cream to dark brown, although some specimens may present small and very diffuse whitish spots.

Regarding the other species of Pachydactylus occurring in Angola but not belonging to the "northwestern group", P. maiatoi sp. nov. differs from P. vanzyli by the presence of four (4) subdigital undivided lamellae on fourth toe (versus two (2) in the latter), from P. rangei and P. wahlbergii by having enlarged, keeled dorsal scales (versus atuberculate and very smooth skin). It can be further distinguished from P. vanzyli and P. rangei by its free digits (versus webbed digits of pes or both manus and pes in the latter), and its general color (pinkish in P. rangei versus cream to brown in P. maiatoi sp. nov.). Pachydactylus rangei only occurs in dunes and in very sandy regions including dry river beds, whereas the new species is rupiculous. It differs from P. cf. rugosus by its much less spiny appearance and by its dorsal coloration pattern (mostly homogeneous cream to brown in P. maiatoi sp. nov. versus cream bands on brown dorsum in P. cf. rugosus ).

Description of Holotype.

Adult male. SVL 36.1 mm (Fig. 5 ; Table 3 ). Body moderately depressed, elongate (TrunkL/SVL 0.45). Head short (HeadL/SVL 0.28), moderately wide (HeadW/HeadL 0.66), depressed (HeadH/HeadL 0.38), slightly distinct from neck. Lores inflated; interorbital region flat. Snout slightly acuminate and convex, and moderately long (SnEye/HeadL 0.39), longer than eye diameter (OrbD/SnEye 0.57); scales on snout and canthus large, smooth, flattened, heterogeneous in size and shape; scales of interorbital and parietal regions heterogeneous, regularly scattered with tiny granules interspersed with larger conical to rounded tubercles. Eye small (OrbD/HeadL 0.22), with 10-12 superciliaries and posterodorsal corner of orbit bearing very small spines; pupil vertical, with crenellated margins; Ear-opening small, horizontally ovoid (EarL/HeadL 0.06). Eye to ear distance higher than the diameter of eye (EyeEar/OrbD 1.39). Rostral approximately 50% as deep as wide, no rostral groove, contacted by two enlarged supranasals and first supralabials; nostrils oval, each surrounded by two postnasals, supranasal, without contact with the first supralabial or rostral; supranasals in contact; one row of scales separates orbit from supralabials; mental elongate, deeper than wide; no enlarged postmentals or chin shields. Enlarged supralabials (left/right) counted to rictus 7/8 (6 to mid-orbit); infralabials 6/7; interorbital scale rows between superciliary rows at midpoint of orbit 19 (8 across narrowest point of frontal bone).Dorsal tubercles large (about ten times the size of adjacent scales), largest dorsolaterally and smallest along dorsal midline rounded, with a pronounced median keel, forming 16 regular longitudinal rows on trunk, grading into posteriorly-directed, conical scales on lower flanks; each tubercle surrounded by an irregular rosette of about 3 to 7 small domed to conical scales; ventral scales flattened, rounded to oval, subimbricate to imbricate, mostly homogeneous, largest on precloacal region, approximately 30 between lowest conical granular rows on flank at midbody; chin granules approximately one fifth the size of ventral scales, increasing in size rather abruptly between gular region and chest. No precloacal or femoral pores. Scales on palm, sole, and ventral surface of forelimb smooth, granular; scales on dorsal aspect of forelimb small, smooth, heterogeneous, subimbricate; scales on preaxial and ventral aspects of thighs somewhat enlarged, smooth, imbricate; scales on dorsum of thigh non-tuberculate, heterogeneous, small to large, flattened to conical; scales on dorsum of crus small, conical, with scattered large (about eight times the size of adjacent scales), keeled round tubercles. Forelimbs short, stout (ForeaL/SVL 0.13); hindlimbs short (CrusL/SVL 0.15); digits short; subdigital scansors, except for distal-most, entire, present only on distal portion of toes, approximately 1.5 times wider than more basal (non-scansorial) subdigital scales; interdigital webbing absent. Relative length of digits (manus): III ~ IV> V> II> I; (pes): IV> III> V> II> I. Subdigital scansors (excluding small distal divided scansor) I (3), II (3), III (3), IV (3), V (3) - manus; I (4), II (4), III (4), IV (4), V (3) - pes. Tail sub-cylindrical, fully regenerated; weakly depressed; postcloacal spurs present.

Coloration of the Holotype.

Dorsum almost homogeneous brown with small and diffuse whitish spots (Fig. 5 ). Dark facial band extending from snout, through the eye and becoming more evident from the posterior part of the eye to right above the ear opening, stopping before the ear opening. Top of head beige slightly lighter than the dorsum. Supralabials and infralabials completely white. Limbs of the same color of the dorsum but digits paler. Venter cream with brown spots on limbs and tail. Tail lighter than the dorsum. Life coloration (Fig. 5A ) is similar to that in preservative (Fig. 5B ).

Variation.

Variation in mensural and meristic characters of the holotype and adult paratypes are presented in Table 3 . All paratypes agree entirely with the holotype and have a similar coloration pattern, only varying the tone of the coloration - from beige (e.g., CAS 254887, 264267; 266484, 266486) to darker brown (e.g., CAS 264256; MB03-001246). Some specimens (CAS 254887, 266484) present very faded brown spots on venter region. The juvenile paratype (CAS 254887, SVL 23.4 mm, Fig. 7 ) has similar coloration to that of adults, but the tail presents very vague darker bands.

Distribution and habitat.

Pachydactylus maiatoi sp. nov. appears to be restricted to southwestern Angola, namely in the inland regions of northern Namibe Province and along the highlands associated with the Angolan escarpment (Fig. 8 ). Individuals were collected under rocks in areas with sparse vegetation, but always associated to inselbergs (Fig. 9 ). It is expected that the species also occurs in neighboring areas of Benguela Province, but so far, no records of the species have been found in that province. The new species has a rupiculous habitat, while P. angolensis , as observed by the authors, is terrestrial with a habitat preference similar to that of P. punctatus .

Conservation.

Pachydactylus angolensis as previously construed was evaluated as a stable species of Least Concern ( Ceríaco et al. 2020 d). Although only Pachydactylus angolensis sensu stricto is represented in a formal conservation area (i.e. Chimalavera Regional Natural Park), both species are relatively widespread in regions that are subject to minimal habitat transformation. Following the IUCN Red List criteria and guidelines ( IUCN Standards and Petitions Committee 2019), and using the GeoCAT: geospatial conservation assessment tool ( Bachman et al. 2011), we estimated an extent of occurrence of around 13.700 km2 for Pachydactylus maiatoi sp. nov. and 18.500 km2 for P. angolensis , which classify both species as Vulnerable (VU) based on their extent of occurrence. However, further research on the extent of occurrence, population trends and ecology of these species is fundamental for a formal assessment of their conservation status.

Etymology.

The species is named after the Angolan biologist Francisco Maiato Gonçalves (Huambo, 1982-), a researcher and curator of the Herbarium of Lubango (ISCED), and vice-dean for Research and International Affairs at the University Mandume Ya Ndemufayo, Huíla Province, Angola. Francisco Maiato Gonçalves represents a new generation of Angolan researchers and a driving force in the study and conservation of southern Angolan biodiversity. The specific epithet is a patronym in the masculine genitive singular. We propose the English common name of Maiato’s thick-toed gecko and the Portuguese common name of osga-de-dedos-grossos-de-Maiato.

Figures

Figure 5. Photos of the holotype (CAS 266485) of P. maiatoi sp. nov., (A) life and (B) preserved, from N'Dolondolo, Namibe Province, Angola. Photo by Luis M. P. Ceriaco.

Figure 6. Life photo of one the paratypes (CAS 264267) of P. maiatoi sp. nov., from Maungo, Namibe Province, Angola. Photo by Luis M. P. Ceriaco.

Figure 7. Juvenile paratype (CAS 254887) of Pachydactylus maiatoi sp. nov.. Photo by Luis M. P. Ceriaco.

Figure 8. Distribution of Pachydactylus angolensis and Pachydactylus maiatoi sp. nov. in Angola. Stars represent the respective type localities; dotted symbols denote localities represented in the phylogenetic analysis.

Figure 9. A Type locality of Pachydactylus maiatoi sp. nov., N'Dolondolo, Serra da Neve inselberg, northern Namibe Province. Photo by Ishan Agarwal. B Collecting locality of the paratype (CAS 264267) in Maungo region, central Namibe Province. Photo by Luis M. P. Ceriaco.