Lygodactylus tantsaha, Vences & Multzsch & Gippner & Miralles & Crottini & Gehring & Rakotoarison & Ratsoavina & Glaw & Scherz, 2022

Vences, Miguel, Multzsch, Malte, Gippner, Sven, Miralles, Aurélien, Crottini, Angelica, Gehring, Philip-Sebastian, Rakotoarison, Andolalao, Ratsoavina, Fanomezana M., Glaw, Frank & Scherz, Mark D., 2022, Integrative revision of the Lygodactylus madagascariensis group reveals an unexpected diversity of little brown geckos in Madagascar’s rainforest, Zootaxa 5179 (1), pp. 1-61 : 25-28

Lygodactylus tantsaha sp. nov.

Lygodactylus sp. 10: Gippner et al. (2021)

Holotype. ZSM 196 /2018 (field number MSZC 0772 ), adult male, collected by M.D. Scherz, J.H. Razafindraibe, A. Razafimanantsoa, and S.M. Rasolonjavato at Montagne d’Ambre, west slope, northern Madagascar, at geographical coordinates S12.58503, E49.11596, 817 m. a.s.l., on 8 December 2017 at 22h20 ( Fig. 15 ).

Paratype. ZSM 197 /2018 ( MSZC 0771 ), collected by M.D. Scherz, J.H. Razafindraibe, A. Razafimanantsoa, and S.M. Rasolonjavato at Montagne d’Ambre, west slope, Madagascar, at geographical coordinates S12.58548, E49.11697, 820 m a.s.l., on 8 December 2017 at 21h36 .

Diagnosis. Lygodactylus tantsaha sp. nov. corresponds to a genetically highly distinct lineage from northern Madagascar that is not closely related to any nominal species of Lygodactylus as defined in the previous sections. It belongs to subclade A2 within Domerguella as defined herein. It can also be assigned to the subgenus Domerguella by an undivided mental scale with two postmentals, absence of a claw on the first finger, and 7 preanal pores in males. Within Domerguella , the new species is only known from Montagne d’Ambre in northern Madagascar and differs from the other Domerguella occurring in this region as follows: from L. expectatus by non-enlarged dorsolateral scales (longitudinal count of dorsal scales>230 vs. <170), from L. rarus by lack of regular crossbands on tail (vs. presence) and different body shape without elongated limbs (relative hindlimb length 0.45–0.50 vs.>0.55); from L. madagascariensis by asymmetrical postmental scales (vs. symmetrical); from L. petteri by a larger longitudinal count of dorsal scales (239–240 vs. 189–222). Genetically, the new species is highly distinct from all species in subclade A5, and differs from almost all of them (potentially not L. fritzi sp. nov. described below) by an absent or only weakly expressed lateral spine at the tail base of males (vs. presence of a distinct spine).

Tentatively, L. tantsaha sp. nov. differs in coloration from other Domerguella by the distinctly white upper lip (vs. brown in all other species) and white spots along the flank (vs. absent or at most light gray in L. madagascariensis and L. miops ).

The new species, on Montagne d’Ambre, occurs sympatrically with L. madagascariensis and L. petteri and is morphologically quite similar to these species, differing only in faint meristic characters as specified above. However, the fully concordant differentiation in mitochondrial genes (deep divergence in 16S:>13% to both L. madagascariensis and L. petteri ) and in the unlinked loci CMOS and RAG-1, despite close syntopy, confirms this lineage represents a distinct species with restricted or absent gene flow to other co-occurring Domerguella .

For a distinction from other species newly named and described herein, see the respective diagnoses below.

Etymology. We are pleased to dedicate this species to Aaron M. Bauer in recognition of his extraordinary work fostering our knowledge about gecko diversity, biology, and evolution. The species name is derived from the Malagasy word tantsaha = farmer, in allusion to the original root of Aaron’s surname Bauer (German) = farmer. Coincidentally, individuals assignable to this species were found at the edge of an area of illegal farming within the park on the west slope, giving the name a second local meaning.

Description of the holotype. Adult male, hemipenes everted, in moderately good state of preservation ( Fig. 15 ), although the tail is detached, and the right forelimb is largely removed as a tissue sample for molecular analysis. SVL 31.9 mm, original tail (TAL 36.9 mm); for other measurements see Table 1 . Head slightly broader than body. The distance from the tip of the snout to the anterior border of the eye (4.0 mm) is greater than the interorbital distance anteriorly (3.7 mm), and slightly greater than the distance between the eye and ear opening. Snout covered with enlarged granular scales, larger anteriorly on snout, becoming smaller laterally and anteriorly above the eye. Nostril surrounded by three scales: rostral, first supralabial and one supranasal. Mental scale undivided; only slight contact between posterior projection of mental scale and first infralabial; two asymmetrical postmental scales; four postpostmental scales; seven infralabial scales; seven supralabial scales; three internasal scales; granular dorsal scales; dorsum with small, homogeneous, granular and unkeeled scales of similar size to those on trunk, the scales on limbs are distinctly larger; 239 dorsal scales longitudinally along the body; 111 ventral scales between mental and cloaca; venter with large homogeneous smooth scales; no obvious lateral spines at the base of the tail; first finger present but very small, without bearing a claw; three pairs of subdigital lamellae on the fourth toe; one weakly expressed dorsolateral tubercle on either side, each composed of 1–2 scales; 7 preanal pores; tail without whorls.

The holotype’s coloration in life based on available photographs was dorsally brown with a diffuse pattern consisting of dark and light spots, venter whitish. Flanks brighten towards venter with a diffuse ocelli-like pattern. Brown color on head with distinct border on supralabials to whitish venter. Six black stripes radially arranged around the eye. Tail slightly brighter than dorsum with pairs of black and white spots running posteriorly along the caudal spine ( Fig. 16A ). After four years of preservation in ethanol, the specimen darkened and patterns faded. Preserved specimen displays dark irregular spots on whitish gular region expanding to the anterior ventral torso.

Variation. The coloration of this species appears tentatively to be characteristic, with a series of white spots always present along the flank in life ( Fig. 16 ). The upper lip is also white.

Natural history. All individuals were encountered and collected at night sleeping at the ends of very thin twigs, narrower than their bodies ( Fig. 16D ).

Distribution. L. tantsaha is only known from the type locality, western Montagne d’Ambre.

Figures

FIGURE 15. Dorsal and ventral views of preserved holotypes of new species of the Lygodactylus madagascariensis group named in the current study.

FIGURE 16. Photos of specimens of Lygodactylus tantsaha sp. nov. from Montagne d’Ambre in life. A, Adult male holotype, ZSM 196/2018 (MSZC 0772); B, specimen MSTIS 928 (voucher not collected); C, D, Adult male paratype, ZSM 197/2018 (MSZC 0771). Not to scale.