Morphological groupings within Euphlyctis (Anura: Dicroglossidae) and description of a new species from the surroundings of Thattekad Bird Sanctuary, Kerala, India

The skittering frog genus Euphlyctis is known to have a distribution range from Arabian Peninsula to Bangladesh through India and Sri Lanka. Although species descriptions were initiated about two centuries ago in the genus with a small number of species described, taxonomic identities and genetic information for many species are still incomplete / inaccurate. Here, we report the systematic status of this group, discuss a series of taxonomic issues, and describe a new species. Based on morphological characters and colour patterns, and their reciprocal monophyly in the molecular tree, two morphological groups, 'cyanophlyctis group' and 'hexadactylus group' are established within the genus Euphlyctis. We discuss the genetic identity for E. cyanophlyctis, described 220 years ago from the Indian subcontinent, from the surroundings of its type locality. E. mudigere is proposed as a junior synonym of E. cyanophlyctis as it was described from populations here considered to originate from the general distribution area of the latter taxon, and without substantial genetic divergence from other populations here attributed to E. cyanophlyctis. The potential of resurrection of Euphlyctis seistanica due to distinct genetic population in Iran is discussed; this lineage appears to be genetically rather similar to E. kalasgramensis, and the species distinctness of these two lineages requires further study. The validity of E. kalasgramensis is also discussed in the context of the historically earlier nomina, Rana bengalensis and Rana leschenaultii due to distribution range overlaps. The prospects of establishing either Rana cyanophlictis variety fulvus or Rana cyanophlictis variety flavens from Sri Lanka are also mentioned. Based on a comparative account, we report the discovery of a new species of skittering frog Euphlyctis kerala sp. nov. which has a restricted distribution in the western coastal plains of India, south of the Palghat gap.