An additional level of cryptic diversity: a new green-coloured Malagasy treefrog of the Boophis luteus species group

New genetic, bioacoustic and morphological data on green-coloured Boophis treefrogs from eastern Madagascar reveal an additional level of cryptic diversity in these frogs. Two candidate species, Boophis sp. Ca36 and Ca37, are closely related to each other and to B. sandrae, with uncorrected pairwise distances in the mitochondrial 16S rRNA gene as low as 2.2% between some individuals. However, the three lineages show full concordance between differentiation in the 16S and the nuclear-encoded SACS gene, despite confirmed syntopy of B. sandrae and B. sp. Ca37 in the Ranomafana region, and probable syntopy of B. sp. Ca36 and B. sp. Ca37 in the Andasibe region. Most likely, these lineages are also divergent in advertisement calls, but the available recordings cannot be reliably assigned to either of them. Based on new material collected from various new sites, we here formally name B. sp. Ca36 as new species B. asquithi sp. n., and suggest targeted fieldwork on calls and larval stages to allow for a complete and fully conclusive taxonomic revision of this species complex. The example of these frogs illustrates how continued underestimation of cryptic diversity in anurans can lead to incorrect assignment of specimens, and leads us to emphasize the importance of designating as name-bearing types (holotypes) of anurans only individuals whose identity is unambiguous by genetic data or, at least, call recordings reliably assignable to the type specimen