A distinctive new frog species (Anura, Mantellidae) supports the biogeographic linkage of two montane rainforest massifs in northern Madagascar

Molly C Bletz,Jary H Razafindraibe,Miguel Vences,Mark D Scherz,Fanomezana Mihaja Ratsoavina,Steven Megson,Frank Glaw,Oliver Hawlitschek,Andolalao Rakotoarison

doi:10.3897/zse.94.21037

Abstract

We describe a new species of the genusGephyromantis, subgenusVatomantis (Mantellidae, Mantellinae), from moderately high elevation (1164–1394 m a.s.l.) on the Marojejy, Sorata, and Andravory Massifs in northern Madagascar. The new species, Gephyromantis (Vatomantis) lomorinasp. n.is highly distinct from all other species, and was immediately recognisable as an undescribed taxon upon its discovery. It is characterised by a granular, mottled black and green skin, reddish eyes, paired subgular vocal sacs of partly white colour, bulbous femoral glands present only in males and consisting of three large granules, white ventral spotting, and a unique, amplitude-modulated advertisement call consisting of a series of 24–29 rapid, quiet notes at a dominant frequency of 5124–5512 Hz. Genetically the species is also strongly distinct from its congeners, with uncorrected pairwise distances ≥10 % in a fragment of the mitochondrial 16S rRNA gene to all other nominalGephyromantisspecies. A molecular phylogeny based on 16S sequences places it in a clade with species of the subgeneraLaurentomantisandVatomantis, and we assign it to the latter subgenus based on its morphological resemblance to members ofVatomantis. We discuss the biogeography of reptiles and amphibians across the massifs of northern Madagascar, the evidence for a strong link between Marojejy and Sorata, and the role of elevation in determining community sharing across this landscape.

Highlights

In recent decades, the number of frog species that have been discovered in Madagascar, while steadily increasing (Köhler et al 2005), often included species that were not immediately recognizable as new to science, though with occasional exceptions, e.g. Boophis lichenoides (Vallan et al 1998), Scaphiophryne boribory (Vences et al 2003), and Tsingymantis antitra (Glaw et al 2006)
Because the obtained tree confirmed the new species to be related to the Laurentomantis/Vatomantis clade as strongly suggested by morphology, we focused our analysis on this subgroup, i.e., all nominal species of the subgenera Laurentomantis and Vatomantis, and G. klemmeri which is known to be related to these subgenera (Kaffenberger et al 2012), as well as G. granulatus as outgroup
Exploratory phylogenetic analyses including all species of Gephyromantis clearly suggested their relationships with the subgenera Laurentomantis and Vatomantis, which is strongly supported by morphological affinities, in particular by the greenish dorsal colour, granular skin, riparian habits, and paired subgular vocal sacs of partly white colour in males

Summary

Introduction

The number of frog species that have been discovered in Madagascar, while steadily increasing (Köhler et al 2005), often included species that were not immediately recognizable as new to science, though with occasional exceptions, e.g. Boophis lichenoides (Vallan et al 1998), Scaphiophryne boribory (Vences et al 2003), and Tsingymantis antitra (Glaw et al 2006). Vieites et al 2012) Differing from this general pattern, on a 2012 expedition to the Sorata massif in northern Madagascar, we discovered a small green frog of the genus Gephyromantis that was immediately recognisable as a new species. It was not given a candidate species number at the time, and no sequences of this species were included in the barcoding assessment of Perl et al (2014).

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Conclusion