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.
Subject(s)
Ephemeroptera , Animals , China , Forelimb , NymphABSTRACT
Previously, only three of seven species in the Asian genus Notacanthurus were reported both nymphs and imagoes, and no Chinese species was found. Here two new species collected from China, which are named as Notacanthurus maculatus sp. n. and N. lamellosus sp. n. respectively, are described and pictured in detail. The nymph of N. maculatus sp. n. has following combined characters: posterior margin of sternum IX straight, claws with two subapical denticles, and gills V-VI with arrow-like accessory lobes. The male imago has unspecialized anterior margin of head and Electrogena-like penis lobes. The second species N. lamellosus sp. n. is more distinguishable. Its nymph has pale dots on head, median dorsal ridges on abdominal terga I-IX, claws with five subapical denticles, and dorsal lamellae of gills II-IV divided into two portions. Anterior margin of male imago is not protruding either, forewings have less pigmented crossveins between Sc and R1, and penis lobes have apical and ventral sclerites. A key to all known nymphs of the genus is provided.
Subject(s)
Ephemeroptera , Animals , China , Gills , Head , Male , NymphABSTRACT
Among the 17 known species of the genus Cincticostella, only five of them have been reported as both nymphs and imagoes, which does not include the Chinese species C. fusca Kang et Yang (1995). Here the nymphs are redescribed and reared imagoes are reported for the first time, based on material collected from southeastern China. Morphologically, the nymph is unique because of its large body size, expanded genae, pale median stripe on the anterior of the head, and dark tarsi. The male imago can be differentiated from congeners by its large body size, pigmented forewings, and the mesothoracic scutellum having a pair of membranous lamellae. More importantly, its penes are distinct, being fused for most of their length and having complex ventral projections. Adults emerge in early spring (March to April).
Subject(s)
Ephemeroptera , Animals , Body Size , Male , NymphABSTRACT
The detailed morphology and phylogenetic positon of Parafronurus youi Zhou Braasch, 2003 have not been discussed especially so far. In this study, we re-describe and illustrate all stages in more detail. Compared to other genera in the subfamily Ecdyonurinae, the nymph of P. youi is characterized by rounded supracoxal spurs, rounded rectangular head capsule, dense setae on dorsal side of labrum, simple proximal and distal dentisetae, primarily swimming setae of caudal filaments. Upon the latter two characters, this genus seems closer to Asian Rhithrogeniella Ulmer, 1939.
