Integrative revision of the Lygodactylus madagascariensis group reveals an unexpected diversity of little brown geckos in Madagascars rainforest.

The Lygodactylus madagascariensis species group, constituting the subgenus Domerguella, currently contains five valid species of inconspicuous dwarf geckos from Madagascars humid forests, but at least 18 deep genetic lineages have been revealed by recent molecular studies. Given the high morphological similarity of these lineages, taxonomic resolution of this astonishing diversity requires efforts to correctly delimit species, as well as assigning the available nomina to the species-level lineages identified. We here combine DNA sequences of one mitochondrial and two nuclear-encoded gene fragments with morphometric measurements and scale counts, and report evidence for a species status of most of the previously identified lineages. In particular, we rely on sympatric and often even syntopic occurrence of several of these lineages without evidence for genetic admixture, and consistent with subtle morphological differences. Furthermore, the very high divergences of 7.423.8% pairwise distances in the relatively conserved mitochondrial 16S rRNA gene, combined with a lack of haplotype sharing in the nuclear-encoded genes and differences in scale counts convinced us that most of the other, allopatrically distributed lineages also represent distinct species. We elevate L. madagascariensis petteri to species level and formally name eight new species: L. salvi sp. nov., a species from the Sambirano region in northern Madagascar, previously called L. sp. 8; L. tantsaha sp. nov. (L. sp. 10), a species occurring sympatrically with L. madagascariensis and L. petteri on Montagne dAmbre in far northern Madagascar; L. roellae sp. nov. (L. sp. 17), a species characterized by a striped coloration in all known specimens, from northern Madagascar; L. winki sp. nov. (L. sp. 18), an unstriped species from northern Madagascar but belonging to a subclade mostly distributed in the eastern rainforests of the island; L. ulli sp. nov. (L. sp. 21), a species from the same subclade as L. winki but known only from the Marojejy Massif in the North East; L. fritzi sp. nov. (L. sp. 11), a further species of this subclade from coastal lowlands in the Northern Central East; L. hodikazo sp. nov. (L. sp. 23) known from a single specimen collected at the Tsingy de Bemaraha and therefore the only Domerguella species known from the West region of Madagascar; and L. hapei sp. nov. (L. sp. 26), an enigmatic species from the Sambirano region characterized by a striped pattern on the throat that is otherwise unknown in the subgenus. Three additional deep mitochondrial lineages of Domerguella were identified in our analysis, but could not be further analyzed due to the lack or scarcity of voucher specimens. More field work and collection of voucher specimens is needed to understand their status. Furthermore, the taxonomy of the Domerguella subclade occurring in eastern Madagascar, with three described species (L. guibei, L. miops, L. fritzi), two synonyms (L. septemtuberculatus, Microscalabotes spinulifer) and at least two further deep genetic lineages co-occurring in a relatively small area, requires further revisionary work, possibly aided by target-enrichment sequencing of the respective name-bearing types.