A Sand-dwelling Mayfly - Analetris eximia
State Rank Reason (see State Rank above)
This sand-dwelling mayfly is currently ranked S3 as a "potential species of concern" in Montana because is potentially at risk of extirpation in the state due to limited and/or declining numbers, range and/or habitat, even though it may be abundant in some areas. The specialized habitat this species requires in prairie rivers has been lost with the damming and diverting of our large prairie rivers such as the Bighorn, Tongue, Milk and Marias.
This swimmer (body-type) mayfly is an inhabitant of large warmwater rivers with shifting sand and gravel substrates. This species is one of the few known predaceous mayflies; they act like tiger beetles on underwater sand bars chasing down prey items, especially chironomids.
This species is confined to a highly specific habitat, is difficult to sample, and is limited to the Saskatchewan, Upper Colorado, and Upper Missouri River Drainage systems; and recently in Montana (MT NHP, March 2006) and North Dakota (Guenther and McCafferty, 2005).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
This species is associated with larger, perennially flowing prairie rivers with shifting sand-gravel dominated bottoms with cobble riffles
This is one of the few known predacous mayflies, they act like tiger beetles on underwater sand bars chasing down prey items. Chironomid midges and blackflies probably make up a large part fo their diet.
Threats or Limiting Factors
All forms of stream quality degradation pose potential threats to these large river dwellers. These include siltation; pollution from agricultural and industrial waste; and hydrological alteration from drainage, dams, or withdrawal of excess water for human use.
- Additional ReferencesLegend: View Online Publication
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- Guenther, J.L. and W.P. McCafferty. 2005. Mayflies (Ephemeroptera) of the Great Plains. III: North Dakota. Transactions of the American Entomological Society, 131(3-4): 491-508.
- Additional Sources of Information Related to "Insects"