Lygodactylus herilalai, Vences & Multzsch & Gippner & Crottini & Glaw & Köhler & Rakotomanga & Rasamison & Raselimanana, 2024

Vences, Miguel, Multzsch, Malte, Gippner, Sven, Crottini, Angelica, Glaw, Frank, Köhler, Jörn, Rakotomanga, Sandratra, Rasamison, Solohery & Raselimanana, Achille P., 2024, Taxonomizing a truly morphologically cryptic complex of dwarf geckos from Madagascar: molecular evidence for new species-level lineages within the Lygodactylus tolampyae complex, Zootaxa 5468 (3), pp. 416-448 : 436-437

Lygodactylus herilalai sp. nov.

( Fig. 8 , 10–12 )

Remark. This species does not correspond to a previously identified genetic lineage or candidate species and was newly discovered in the present study.

Holotype. ZSM 161/2022 (ZCMV 15707), adult female ( Fig. 8 , 10 ), collected by S. Rakotomanga and S. Rasamison at Ampondrabe forest , Ankarafantsika National Park, Madagascar (geographical coordinates 16.3343°S, 46.8987°E, 223 m a.s.l.), on 13 November 2022.

Paratypes. Three specimens: ZSM 160/2022 (ZCMV 15706), male, with same collection data as holotype; UADBA-APR 7501, male, collected by A.P. Raselimanana at Ampondrabe forest , Ankarafantsika National Park (16.325°S, 46.923°E, 270 m a.s.l.), on 2 December 2006 ; UADBA-APR 7588, male, collected by A.P. Raselimanana at Andasiravina forest , Ankarafantsika National Park (16.303°S, 46.930°E, 150 m a.s.l.), on 12 December 2006 .

Diagnosis. L. herilalai sp. nov. is characterized as a member of the L. tolampyae complex (and thereby distinguishable from all other Malagasy Lygodactylus not belonging to the complex) by combination of a mental scale semi-divided by a suture, broad contact of the posterior projection of the mental scale with the first infralabial scale, and three postmental scales; furthermore, characterized by absence of whorls on the tail, and a typical look of the head with relatively large eyes. According to the limited data available, it appears to be distinguished from L. tolampyae sensu stricto (as defined herein; mitochondrial lineages A+B and possibly G) by higher mean and maximum counts of dorsal scales despite wide range overlap (mean 245 vs. 229; ranges 229–262 vs. 204–241; not statistically tested due to low sample size of n= 3 in L. herilalai sp. nov.), possibly by a tendency towards broader posterior contact between mental scale and first infralabial scale, and by fewer (1 vs. 2–3) internasal scales in a high proportion of individuals. The new species is most similar morphologically to the syntopic L. morii , with no differentiating morphological characters known; however, the two species differ strongly in mitochondrial and nuclear DNA sequences. The new species can be differentiated from L. morii and all other lineages in the L. tolampyae complex by numerous diagnostic nucleotide positions in the mitochondrial 16S rRNA gene: MolD identified a robust diagnostic nucleotide combination of a ‘C’ in the site 959, ‘A’ in the site 1017, ‘T’ in the site 1042 (positions relative to the full 16S rRNA gene of Phelsuma guimbeaui ).

Description of the holotype. Adult female, in good state of preservation, left forelimb removed as tissue source for molecular analysis. SVL 31.0 mm, TAL 31.6 mm; for other measurements, see Table 2 . Body broader than head. The distance from the tip of the snout to the anterior border of the eye (4.0 mm) is equal to the anterior interorbital distance (4.0 mm), and greater than the distance between the eye and ear opening (2.9 mm). Snout covered with granular scales larger than those on the dorsum. Nostril surrounded by five scales: rostral, first supralabial, one postnasal and two supranasals. The mental scale is semi-divided; contact between posterior projection of mental scale and first infralabial scale is roughly 30% of the infralabial scale length; three symmetrical postmental scales, followed by five post-postmentals; six infralabial scales; seven supralabial scales; one internasal scale; granular dorsal scales; dorsum with small, homogeneous, granular, and unkeeled scales of similar size to those on trunk, no distinct scale size difference on limbs; 243 dorsal scales longitudinally along the body; 98 ventral scales between mental and cloaca; venter with larger homogeneous smooth scales; first finger present, small, but bearing a claw; three pairs of subdigital lamellae on the fourth toe; six not very distinct dorsolateral tubercles, each consisting of one to three scales; tail without whorls; no observable lateral spines at the base of the tail.

Based on available photographs ( Fig. 8 ), in life the holotype specimen displayed a brownish to grayish colouration on the dorsum and limbs. Above the spinal cord was a darker stripe, paired with a repeating pattern of lighter spots slowly fading to a darker colour on each side. The spots unified into a single spot on the tailbase, from where the pattern was weakened in colouration. On the head were some yellowish scales. On the neck and between the limbs were yellowish tubercles. The limbs were vaguely patterned with stripes of lighter and darker colouration at the same strength as the dorsum. The ventral side was whitish with a darker colouration on the legs and tail, and without a pattern ( Fig. 8 ). After 6 months in ethanol ( Fig. 10 ), the specimen is overall darkened in colouration with the pattern still clearly visible. The yellow spots and tubercles are more whitish. The ventral side lost its whitepinkish colour for a more white-yellowish colouration and a few slightly darker spots appeared in the throat area.

Etymology. The name is a patronym for Herilala Jean Aimé Rudolph Randriamahazo, Malagasy field herpetologist and conservation biologist, in recognition for his contributions to our understanding of the ecology of various reptile species in Ankarafantsika National Park, and to the conservation of Malagasy amphibians and reptiles. The species epithet is a noun in the genitive case.

Variation. For variation in morphometric and scalation characters, see Table 2 . Body size ranged between 24.4–31.0 mm in males, vs. 31.0 in the female holotype.

Natural history. Individuals in Ampondrabe Forest ( Fig. 13 ) were found active during the day on tree trunks in November 2022. UADBA-APR 7501 was collected at 20:00 h, roosting at the extremity of a tiny branch at 1.5 m above the forest floor, in dry deciduous forest with sandy soil. UADBA-APR 7588 was found at 19:00 h roosting at the extremity of a small branch in vertical position with the head in the direction of the extremity of the support (upside-down) in semi-deciduous forest. It was quite common in the forest, mostly on tree trunks below 1.5 m, and when disturbed, they would descend the trunk to hide under loose bark, underneath the roots, or in fallen dry leaves among leaf litter.

Distribution. The species has so far only been found in two sites within Ankarafantsika National Park: (1) Ampondrabe forest and (2) Andasiravina forest.

Figures

FIGURE 8. Female holotype of Lygodactylus herilalai sp. nov., ZSM 161/2022 (ZCMV 15707) from Ampondrabe, Ankarafantsika National Park, in life, photographed November 2022.

FIGURE 10. Preserved holotypes of the three new species of the Lygodactylus tolampyae complex described herein, photographed in May 2023.

FIGURE 11. Ventral views of the heads of the holotypes of the three new species of Lygodactylus described herein, and one representative specimen of L. tolampyae. The images on the right show the mental region magnified and strongly sharpened to improve visibility of sutures between scales. For the holotype of L. morii sp. nov., the typical arrangement of scales in the mental region in this species complex is labelled: M, mental scales (semi-divided by incomplete sutures), PM, post-mentals (typically three), IL1, first infralabial (which maintains a broad contact with the mental). Scale bars (referring to the images on the left) represent 1 mm.

FIGURE 12. Lateral views of the heads of the holotypes of the three new species of Lygodactylus described herein, and one representative specimen of L. tolampyae. The scale bar represents 1 mm.

FIGURE 13. Habitat of species of the Lygodactylus tolampyae complex. A. Dry deciduous forest at Ampijoroa (Ankarafantsika) where L. morii sp. nov. occurs in high densities. B. View of remains of dry deciduous Ampondrabe forest (habitat of L. morii sp. nov. and L. herilalai sp. nov.) with large areas of forest destroyed by fire in the foreground. C, D. Transitional forest on Sahamalaza Peninsula, habitat of L. schwitzeri sp. nov. E. Forest in the Tsingy de Bemaraha, habitat of L. tolampyae. All photos by the authors except A by P. Galán.