Systematics and evolution of the Potamanthidae (Ephemeroptera)

Yeon Jae Bae, Purdue University

Abstract

A comprehensive comparative morphological and distributional study of mayflies of the family Potamanthidae resulted in the recognition of 23 included species. An analysis of cladistic relationships among them was based on 36 larval and adult characters. A phylogenetic classification, incorporating sequencing, was devised from a highly parsimonious cladogram. It entailed the following revision: Genus Rhoenanthus (=Potamanthindus, Neopotamanthodes, and Neopotamanthus, n. syn.) (subgenus Rhoenanthus s.s.) includes R. distafurcus, n. sp. and R. speciosus. Rhoenanthus (subgenus Potamanthindus, n. stat.) includes R. magnificus (=R. vitalisi, R. ferrugineus, and Neopotamanthodes lanchi, n. syn.); R. obscurus (=Potamanthindus auratus, n. syn.); R. coreanus, n. comb. (=R. rohdendorfi, n. syn.); and R. youi, n. comb. Anthopotamus includes A. distinctus; A. myops (=A. inequalis and A. rufous, n. syn.); A. verticis (=A. diaphanus and A. walkeri, n. syn.); A. neglectus neglectus, n. stat.; and A. neglectus disjunctus, n. subsp. Potamanthus (=Potamanthodes and Stygifloris, n. syn.) (subgenus Potamanthus s.s.) includes P. huoshanensis; P. luteus luteus, n. stat. (=P. ferreri, n. syn.); and P. luteus oriens, n. subsp. Potamanthus (subgenus Stygifloris, n. stat.) includes P. sabahensis, n. comb. Potamanthus (subgenus Potamanthodes, n. stat.) includes P. macrophthalmus, n. comb; P. yooni, n. sp.; P. formosus, (=P. iyonis, n. syn.); P. idiocerus, n. sp.; P. kwangsiensis, n. comb. (=Potamanthodes fujianensis, n. syn.); P. longitibius, n. sp.; P. sangangensis, n. comb.; and P. yunnanensis, n. comb. Potamanthus nanchangi, n. comb., and Potamanthus subcostalis are considered incertae sedis. Rhoenanthus shima is a nomen dubium excluded from Potamanthidae. The family is redefined; genera, subgenera, species, and subspecies are described, illustrated, and keyed morphologically. Nomenclatural histories of all taxa are given; taxon distributions are plotted; and all materials examined are cited. Character polarities and distributions as well as the linear classification are tabulated; cladograms and phylograms are figured. Three major lineages involve Rhoenanthus, representing one of the initial branches (defined by 6 synapomorphies), and the opposite initial branch (defined by 6 synapomorphies) leading to the most recent hypothetical ancestor of Anthopotamus (defined by 3 synapomorphies) and Potamanthus (defined by 4 synapomorphies). The phylogeny and thus generic classification is highly reflective of considerable previously unstudied larval characterization. All genera have filter-feeding larvae, however, based on correlations of ultrastructure and function, Anthopotamus is the most specialized. Potamanthus has reduced tusks and other apomorphies possibly related to differences in feeding or burrowing. The family demonstrates a Laurasian (Nearctic, Palearctic, and Oriental) distributional pattern. Area cladograms were generated to hypothesize historical biogeography of genera and subgenera, which is highlighted by a major East-West Hemispheric vicariance between North American Anthopotamus and Eurasian Potamanthus.

Degree

Ph.D.

Advisors

McCafferty, Purdue University.

Subject Area

Entomology

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