Abstract

The potamanthid mayfly genus Rhoenanthus Eaton, which was not investigated systematically before in China, is revised herein. Six species in the subgenus Potamanthindus are recognized. Among them, R. sapa, R. obscurus and R. coreanus are new records for this country, and the presence in China of the species R. magnificus and R. hunanensis is confirmed, the nymphal stage of the latter species being described for the first time. Phylogenetically and evolutionarily, R. sapa, which has shorter maxillary and labial palpi, foretibiae and less setaceous mouthparts and forelegs, is close to the plesiomorphic genus Potamanthus. At the same time, R. youi, R. obscurus and R. coreanus, which have larger tusks and spines, longer and more setaceous foretibiae, maxillary and labial palpi, are somewhat similar to the other subgenus Rhoenanthus (Rhoenanthus). The Chinese Rhoenanthus (Potamanthindus) species indicate that the genus Rhoenanthus is closer to Anthopotamus rather than Potamanthus, both of them bearing elongated mandibular tusks.