Vertebrate Zoology 63(2): 193-205, doi:
Assessing the diversity of phytotelmic frogs along Madagascar’s east coast: Redefinition of Guibemantis bicalcaratus (Boettger, 1913) and revalidation of Guibemantis methueni (Angel, 1929)
expand article infoMiguel Vences, Andolalao Rakotoarison, Andry Malalan’Ny Aina Rakotondrazafy, Fanomezana Mihaja Ratsoavina, Roger Daniel Randrianiaina, Frank Glaw, Richard M. Lehtinen, Christopher J. Raxworthy
‡ Technische Universität Braunschweig, Braunschweig, Germany
Open Access
Guibemantis bicalcaratus (Boettger, 1913) has been considered as a widespread member of the subgenus Pandanusicola of largely phytotelmic-breeding Malagasy frogs. Based on new collections from its type locality, the Malagasy island Nosy Boraha, and several other localities on Madagascar’s east coast, we revise the status of G. bicalcaratus using molecular and morphological data. Mitochondrial DNA sequences of the 16S rRNA gene demonstrate the presence of two deep genealogical lineages of Pandanusicola on Nosy Boraha. Of these, one so far has only been found on Nosy Boraha whereas the second is also present at several other localities along the central east coast of Madagascar. Specimens assigned to the two mtDNA lineages did not share alleles in sequences of the nuclear RAG1 gene except for one specimen, suggesting reduction or absence of gene flow despite sympatry, with occasional hybridization. No differences between the two lineages were found in external morphology but faint differences in color allowed us to discriminate the majority of specimens, and we therefore conclude that they should be considered as belonging to two distinct species. Based on these chromatic differences and comparison with type specimens, we assign the species present only on Nosy Boraha to Guibemantis bicalcaratus whereas the second species also occurs at Ambila, the type locality of Gephyromantis methueni Angel, 1929. We consequently resurrect this nomen as Guibemantis methueni for this species. It is likely that the two species are restricted to relatively small ranges on Madagascar’s central east coast, but due to the rudimentary knowledge on their distribution and habitat requirements we suggest a threat status of Data Deficient for both of them.
Mantellidae; Guibemantis; Pandanusicola; Guibemantis bicalcaratus; Guibemantis methueni; Nosy Boraha; Madagascar; Taxonomy