Well known does not mean well studied: morphological and molecular support for existence of sibling species in the Javanese gliding frog Rhacophorus reinwardtii (Amphibia, Anura).

Morphological, morphometrical and molecular data support the existence of two sibling species in the taxon previously known as Rhacophorus reinwardtii. The two species can be distinguished by the coloration pattern of webbing, the size of adult specimens and the relative size of various morphometric characters. This long and commonly known taxon should be separated into two species. As a consequence, the conservation status of the new species Rhacophorus kio n. sp. as well as of the redefined species Rhacophorus reinwardtii must be re-evaluated and, considering the new distribution data and the particular ecological demands, both species should be considered as 'endangered'.