Two new species of the Spinomantis bertini species complex (Mantellidae) from south-eastern Madagascar

We scientifically name and describe two new species of spiny frog (Mantellidae: Spinomantis) from moderately high elevations in Ranomafana National Park, in south-east Madagascar. This region has been surveyed extensively and has a remarkably high anuran diversity with many undocumented species still being regularly discovered. We describe a previously identified candidate species, S. sp.

Ca 07, as Spinomantis lavabato sp. nov. and a previously undiscovered species from this region as Spinomantis lakolosy sp. nov. . The new species are morphologically cryptic within the S. bertini complex but can be recognized by a combination of subtle differences in coloration such as a lack or weak expression of sharp dorsolateral color border in both species. Bioacoustically, the new species are quite different from other species in the complex: Spinomantis lakolosy sp. nov. has the longest note duration with a powerful-sounding call that rings like a bell, which can be heard over the sound of rushing water in nearby streams; while S. lavabato sp. nov. differs by having the shortest note duration that is quiet and sounds like a trill.

Furthermore, both species are substantially diverged in mitochondrial DNA, with pairwise distances in a fragment of the 16 S rRNA marker of 7–9 % to all other related species. Furthermore, we identify a lineage for future study in the complex from the nearby high-elevation site Andemaka within Ranomafana National Park that has an intermediate sounding advertisement call between the newly described species; although we cannot formally describe this lineage herein due to unavailability of voucher specimens, this lineage emphasizes the unexpectedly high diversity of sympatric species of the S. bertini complex in the Ranomafana area.

Additionally, we identify another lineage from Ambahavala in the Anosy Chain with strong mitochondrial divergence for future study. Our findings also highlight the need for continued inventory work in high elevation rainforests of Madagascar, even in relatively well-studied regions such as Ranomafana National Park.