Hemidactylus carivoensis, Lobón-Rovira & Conradie & Iglesias & Ernst & Veríssimo & Baptista & Pinto, 2021

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 carivoensis sp. nov.

Figs 12 and 14

Hemidactylus carivoensis sp. nov. represents a new form genetically divergent from the two related species, with ND2 p-distance of 12.51% from H. cinganji sp. nov. and 12.48% from H. benguellensis (Table 1 ). Given the hypervariable morphology of the H. benguellensis -group, and the lack of molecular and morphological information before Ceríaco et al. (2020a), it is possible that some historical records of H. benguellensis may be assignable to this species. However, the morphological characteristics of H. carivoensis sp. nov. allows it to be unequivocally distinguished from H. benguellensis and H. cinganji sp. nov. (Table 2 ). Moreover, H. benguellensis has not yet been reported within the known distribution range of this newly described species ( Marques et al. 2018; Ceríaco et al. 2020a; this study).

Holotype.

ANGOLA • 1 ♀; Benguela Prov., Fazenda Carivo; -13.19167°, 13.41806°; 382 m a.s.l.; 15 Jul. 2018; Pedro Vaz Pinto; good condition with a ventral-lateral incision for the removal of liver sample and some torn skin in the ventrum; FKH0033.

Paratypes.

ANGOLA • 1 ♀, juv.; Benguela Prov., Santa Maria, Praia do Meva; -13.19167°, 12.99139°; 287 m a.s.l.; 12 Nov. 2016; Pedro Vaz Pinto and William R. Branch; PEM R24218 (field number AG 16.63) • 1 ♂; same collecting locality as holotype; 7 Jan. 2020; MNCN 50542 • ♂; same collecting locality as holotype; Dec. 2020; ZMB 90453 • 1 ♂; Benguela Prov., between Dombe and Equimina; -13.18333°, 12.99139°; 367 m a.s.l.; 14 Feb. 2020; Pedro Vaz Pinto and Javier Lobón-Rovira; MNCN 50543 • 1 ♀; same collecting details as previous material; ZMB 90452.

Additional material.

ANGOLA • 2 ♂, subadult; same collecting locality as holotype; Dec. 2020; MNCN 50544 and FKH0499 • 1 ♀; same collecting locality as previous; FKH0500 .

Diagnosis.

A medium sized Hemidactylus , with SVL of 43.2 mm (mean) and maximum width of 8.8 mm (Fig. 14 ). 9-11 supralabials and 8-10 infralabials. Dorsal pholidosis with 15-22 rows of moderate strongly keeled tubercle scales and ventral pholidosis with 32-38 smooth and rounded scale rows around midbody. Hemidactylus carivoensis sp. nov. present a moderate, triangular, moderate rounded posteriorly mental scale, two large postmentals followed by two large post-postmentals. Tail with four strongly keeled dorsal tubercles rows dorsally and subcaudal scales small, about one fourth of the tail width, interspersed by large series of horizontal whorls of keeled scales. Males with 15-22 continuous precloacal-femoral pores. Five divided scansors beneath first digit of both manus and pes, seven or eight beneath fourth digit of manus, nine beneath the fourth digit of pes. Dorsum darker coloration on the dorsal part of the head that continues along the medial part of the dorsum until the sacrum.

Comparative diagnosis.

Hemidactylus carivoensis sp. nov. can be distinguished from other non-Angolan western and central African congeners based on the same characteristics of H. benguellensis ( Ceríaco et al. 2020a). Hemidactylus carivoensis sp. nov. can be distinguished from H. mabouia by the presence of smaller subcaudal scales (vs. large elongated scales). It differs from the H. bayonii -group by the presence of largely keeled dorsal tubercle scales vs. slightly keeled, larger number of precloacal-femoral pores (17-22 vs. 4-9 in H. bayonii , 4-6 in H. vernayi , 7-8 in H. nzingae and 8 in H. gramineus ), larger number of ventral scales across the belly (34-38) than H. bayonii (29-32), H. nzingae (22-27), H. gramineus (23-25) and H. faustus sp. nov. (29-32). The new species differs from H. longicephalus -group by a larger number of precloacal-femoral pores (17-22 vs. 6-11 in H. longicephalus and 6-8 in H. paivae ), smaller SVL (maximum SVL 45.2 mm [mean=43.19] in H. carivoensis sp. nov. vs. 60.07 mm [mean=46.6] in H. longicephalus and 68.4 mm [mean=58.96] in H. paivae ) and lower number of lamellae under 1st toe (5 in H. carivoensis sp. nov. vs. 6-7 in H. longicephalus -group). Hemidactylus carivoensis sp. nov. differs from H. benguellensis -group by less keeled and rounded dorsal tubercles, number of precloacal-femoral pores (15-22 vs. 23-33 in H. benguellensis and 26-28 in H. cinganji sp. nov.), the presence of consecutive series of keeled subcaudal scales under the tail whorls, larger number of ventral scales across the belly (34-38 in H. carivoensis sp. nov. vs. 30-32 in H. cinganji sp. nov.) and large number of supralabials (10-11 in H. carivoensis sp. nov. vs. 9 in H. cinganji sp. nov.) (see Table 2 , for comparison with other Angolan congeners).

Holotype description (Fig. 14 ).

Measurements and meristic characters of the holotype are presented in Table S7. Adult female with a snout-vent-length (SVL) of 45.16 mm and a tail length (TL) about the same size than SVL 44.79 mm. Body slender, nape distinct. Head slightly narrower than the body and largely elongated (HW/HL 0.65). Canthus rostralis not prominent. Eye diameter (3.04 mm), with vertical pupil and crenulated margin. Supraciliar scales small and rounded. Ear height (0.83 mm). Ear to eye distance slightly larger than orbit diameter (3.46 mm). Snout rounded and pointed. Frontal scales granular and larger than occipital scales. Occipital scales granular interspersed with large number of smooth and conical tubercle scales from eyes to nape. Rostral wider than deep (2.31 vs. 0.93 mm, respectively). Rostral semi-divided posterodorsally, in contact with 1st supralabial, nostril, two postnasals and one internasal scales. Eleven supralabials and 9 infralabials. First supralabial in contact with the nostril. Nostril circular rounded by rostral, supranasal and two postnasals. Postnasals larger than supranasal. One or two rows of scales between supralabials and the orbit. Mental large, triangular and rounded posteriorly, with two large rectangular postmental scales in broad contact posteriorly to the mental. 4 post-postmental scales, composed by post-postmental slightly smaller than postmental scales in contact with postmentals and 1st and 2nd infralabials, and 2 post-postmental half size than lateral post-postmental in contact with postmental scales. Gular scales slightly smaller than ventral scales and granular. Between the gular scales and infralabials a row of enlarged scales is present, decreasing in size until the 5th infralabial where they become the same size as the gular scales.

Body relatively robust and slightly elongated (TRL/SVL 0.39). Ventral scales widely larger than dorsal scales, with 36 scales across the belly. The dorsal pholidosis present heterogenous conical, granular scales interspersed by 17 strongly keeled dorsal tubercle rows of at midbody. Dorsal tubercle rows are separated by 3 granular scales. Tubercle scales reach the posterior part of the eye region where tubercle scales lose the keeling progressively. Tail with four strongly keeled dorsal tubercles rows dorsally and subcaudal scales small, about one fourth of the tail width, interspersed by 22 horizontal whorls of keeled scales. Precloacal scales enlarged and one well-developed postcloacal spur on each side.

Fore- and hindlimbs relatively short, stout; forearm short (FL/SVL 0.16); tibia short (CL/SVL 0.18). Short digits and clawed. All digits of manus and pes indistinctly webbed. Scansors beneath each toe composed by 1st and two terminal scansor undivided. 4th toes with 3 undivided terminal scansors. Scansors beneath each finger equally divided, with the exception of 1st and last terminal scansors undivided. Number of scansors: 6-6-7-7-7 (right manus), 7-8-9-10-7 (right pes). Relative length of digits: V < IV=III > II > I (right manus); V < IV < III > II > I (right pes).

Variation.

Variation in scalation and body measurements of the paratypes of H. carivoensis sp. nov. are reported in Table S7. All the material analyzed is in agreement entirely with the holotype.

Coloration.

In life (specimen MNCN 50543; Fig. 12A ): this species displays an orange-beige coloration across the body with darker coloration on the dorsal part of the head that continues along the medial part of the dorsum until the sacrum; in the dorsal section presents two lighter dorsolateral bands from the nares to the tail; the ventral part of the head shows a cream coloration with dispersed black speckles that increase towards the anterior part of the infralabials; ventrum is uniform light beige or cream; supralabials are darker than infralabials; fore- and hindlimbs present an irregular dark brownish coloration; tail with similar color and slightly banded; iris silvered with a black narrow pupil and brownish-golden reticulation. In preservative (Holotype; Fig. 14 ): dorsum with dark greyish coloration and two lighter dorsolateral bands from the narine till the sacrum; ventrum is light uniform beige. Variation: ventrum can be uniform beige or present scattered black speckles; crossband of the tail can be present or absent.

Etymology.

The species epithet " Hemidactylus carivoensis " refers to the Farm Carivo, an old estate situated along the banks of the mid-lower Coporolo River on the coastal plain of Benguela Province, and where most of the type series was collected. The species proved to be common in the area, and by recognizing the farm, we also acknowledge the ongoing support from the owners to researchers, similar to the Chapmans nearly a century ago.

Distribution and conservation (Fig. 12C ).

The full distribution range of the species remains unknown, even though so far it has only been confirmed to occur across the coastal plain of western Benguela Province. Due to the variable morphology of the taxon known as H. benguellensis and which formerly included material now assigned to H. cinganji sp. nov., it is possible that some historical material was wrongly identified and should instead belong to this newly described species. Spiny savannas are well distributed in western Angola, suggesting that the new species might be common across a wider range than what is currently known, but available data is still poor. However, due to limited material confirmed to belong to this species, we can’t calculate the EOO and we regard the conservation status of this species as Data Deficient. Therefore, it is important for future studies to establish the real distribution of H. benguellensis , H. cinganji sp. nov. and H. carivoensis sp. nov. to better determine the conservation status of the species.

Natural history and habitat (Fig. 12B ).

Hemidactylus carivoensis sp. nov. represents an arboreal species occurring on coastal savanna habitats dominated by small acacia ( Senegalia spp.) trees and bushes, and often with abundant accumulation of dead wood. Their preferred habitat is well contained within the Semi-arid Savannas. The species was found during night surveys and in sympatry with Afrogecko ansorgii , albeit in different niches. While individuals of A. ansorgii were found foraging in small twigs and branches at medium height of bushes ( Vaz Pinto et al. 2019), H. carivoensis sp. nov. were always collected at the base of bushes and tree trunks, or in fallen branches or dead wood on the ground.

Figures

Figure 12. A - From top, dorsolateral view of Hemidactylus cinganji sp. nov. (FKH 0435), H. benguellensis (FKH 0413) and H. carivoensis sp. nov. (MNCN 50543); B - records of H. benguellensis - group (purple color represents records of H. cinganji sp. nov.; blue H. benguellensis; dark green H. carivoensis sp. nov.; circles represent genetically assigned records, while triangles represent historical or non-genetically assigned records by Ceriaco et al. 2020 a; color stars depict type or neotype localities; black star depicts original type locality of H. benguellensis assigned by Bocage (1893); C - habitat of H. cinganji sp. nov. at Ebanga; D - habitat of H. carivoensis sp. nov between Dombe-Echimina. E - habitat of H. benguellensis at Tchivinguiro. Photos Javier Lobon-Rovira (A-D) and William R. Branch (E).

Figure 14. Holotype of Hemidactylus carivoensis sp. nov. (FKH 0033) from Carivo, Benguela Province, Angola. A - Ventral and dorsal view of body. B - Details of head in lateral, dorsal and ventral views (from top to bottom). C - Details of right toes and left fingers (from left to right). Photos by Pedro Vaz Pinto.