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Ephemeroptera: Ameletidae of Gunnison County, Colorado

Ameletus sparsatus
Brown Dun

McDunnough, 1931
Updated 22 March 2023
TSN 101013


Ameletus aequivocus was synonymized with A. sparsatus.

Good Links

On this website:
Ameletus Introduction

Other websites:
North American distribution map - flyfishingentomology.com


Canton,SP and Chadwick,JW 1983 Seasonal and longitudinal changes in invertebrate functional groups in the Dolores River, Colorado. Freshwater Invertebrate Biology, 41-47. PDF

Hamilton,H and Clifford, F 1983 The seasonal food habits of mayfly (Ephemeroptera) nymphs from three Alberta, Canada, streams, with special reference to absolute volume and size of particles ingested. Arch. Hydrobiol., Suppl, 65(2/3), 197-234. PDF

Heinold,B 2010 The mayflies (Ephemeroptera), stoneflies (Plecoptera), and caddisflies (Trichoptera) of the South Platte River Basin of Colorado, Nebraska, and Wyoming. M.S. Thesis, Colorado State University, Fort Collins, CO 375 pages. 148 distribution maps. PDF
     Remarks about A. sparsatus from page 26: " Some previous records from the SPRB for this species were recognized as A. aequivocus (McCafferty et al. 1993). Ameletus sparsatus was collected at elevations between 1633 m and 2223 m. Adults were present between May and July."

McCafferty,WP; Durfee,RS; Kondratieff,BC 1993 Colorado mayflies (Ephemeroptera): an annotated inventory. Southwestern Naturalist 38 3, 252-274. PDF
     The Purdue University Entomological Collection (PERC) has specimens from the Gunnison River. Quote from page 253: Discussed as Ameletus aequivocus. "Until now, this species had been known only from the type material (male adults) from Colorado. Larvae remain unknown, but larvae that have been taken in Colorado and do not fit any other species precisely may prove to be this species. For example, there are distinctive larval specimens in PERC [Purdue Entomology Research Collection] from the Piedra River, Rio Blanco, and Conejos River that are the same but do not fit any presently published description of western Ameletus. Their gill 4 has a subdorsal sclerotized band but no ventral band, and the ventral border possesses 16-19 spines. Their tails are banded, but there is only slight nondescript dorsal and ventral abdominal patterning, and the gills show no distinct tracheation. They are similar to, but still distinct from, Ameletus sp. B of Allen and Chao (1981) from New Mexico, and therefore could be either a) a new species, b) A. falsus (described from Arizona but unknown as larvae), or even c)A. aequivocus or A. subnotatus (see below), although the distribution would suggest a suthwestern affinity."
Quote from page 254, discussed as Ameletus sparsatus. "This species was originally described from Alberta, and the first author has seen specimens from Idaho. Ameletus cooki McDunnough and A. sparsatus can be difficult to distinguish, and the latter may prove to be a junior synonym of the former.

McDunnough,J 1931 New species of North American Ephemeroptera. Canadian Entomologist 63, 82-93.

Miller,SA 1974 The effects of sodium chloride on Hyalella azteca, Ameletus sparsatus, and Tubifex tubifex. MA Thesis, Western Michigan University. PDF

Short,RA and Ward,JV 1980 Macroinvertebrates of a Colorado high mountain stream. The Southwestern Naturalist, 23-32. PDF

Zloty,J 1996 A revision of nearctic Ameletus mayflies based on adult males, with descriptions of seven new species (Ephemeroptera: Ameletidae). Canadian Entomologist 128, 293-346. PDF

Zloty,JS 1998 Systematics of nearctic Ameletus mayflies (Ephemeroptera: Ameletidae). PhD Thesis University of Calgary.
     Abstract: "A systematic revision of North American species of the genus Ameletus, excluding parthenogenetic species, is presented. Seven new species are described (A. andersoni, A. bellulus, A. doddsianus, A. edmundsi, A. majusculus, A. pritchardi, and A. tolae), separate keys are given to western and eastern species, annotated accounts of all 30 presently recognized bisexual species are provided, taxonomic characters are illustrated, and distribution data are presented for all species. The following nomenclatural changes are proposed: Ameletus aequivocus is considered a junior synonym of A. sparsatus; A. alticolus and A. celeroides junior synonyms of A. celer; A. connectina and A. connectus junior synonyms of A. velox; A. facilis a junior synonym of A. vancouverensis; A. monta a junior synonym of A. similior; A. querulus a junior synonym of A. shepherdi; A. tuberculatus is provisionally considered to be a junior synonym of A. celer

Zloty,J and Pritchard,G 1997 Larvae and adults of Ameletus mayflies (Ephemeroptera: Ameletidae) from Alberta. Canadian entomologist, 129(2), 251-290. PDF
     Description of larvae and adults.

Zuellig,RE; Heinold,BD; Kondratieff,BC and Ruiter,DE 2012 Diversity and distribution of mayflies (Ephemeroptera), stoneflies (Plecoptera), and caddisflies (Trichoptera) of the South Platte River Basin, Colorado, Nebraska, and Wyoming, 1873-2010 (No. 606). US Geological Survey. PDF - caution 46MB
      Elevation collected 4,950-8,850 ft. Adults were found February-July. Remarks from page 16: " Some previous records from the SPRB for this species were reported as A. aequivocus (McCafferty and others, 1993)."

Brown, Wendy S. 2004 Mayflies (Ephemeroptera) of Gunnison County, Colorado, USA