A new species of Microhyla (Anura: Microhylidae) from Nilphamari, Bangladesh

Abstract

A new species of Microhyla frog from the Nilphamari district of Bangladesh is described and compared with its morphologically similar and geographically proximate congeners. Molecular phylogeny derived from mitochondrial DNA sequences revealed that although the new species - designated here as Microhyla nilphamariensis sp. nov. - forms a clade with M. ornate, it is highly divergent from M. ornata and all of its congeners, with 5.7-13.2% sequence divergence at the 16S rRNA gene. The new species can be identified phenotypically on the basis of a set of diagnostic (both qualitative and quantitative) characters as follows: head length is 77%of head width, distance from front of eyes to the nostril is roughly six times greater than nostril-snout length, internarial distance is roughly five times greater than nostril- snout length, interorbital distance is two times greater than internarial distance, and distance from back of mandible to back of the eye is 15%of head length. Furthermore, inner metacarpal tubercle is small and ovoid-shaped, whereas outer metacarpal tubercle is very small and rounded. Toes have rudimentary webbing, digital discs are absent, inner metatarsal tubercle is small and round, outer metatarsal tubercle is ovoid-shaped, minute, and indistinct.