Ephemeroptera: Baetidae of Gunnison County, Colorado
Centroptilum Introduction Eaton, 1869
Long-clawed Baetids, Small Minnow Mayflies, Tiny Sulphur Duns
Updated 18 Dec 2018
We may have Centroptilum sp. in the Gunnison basin, possibly Centroptilum album or Centroptilum bifurcatum.
Photos, Map, Museum specimens, DNA - Barcodinglife.org
Photos - from Troutnut.com
Argyle,DW; Edmunds,GF 1962 Mayflies (Ephemeroptera) of the Curecanti Reservoir Basins Gunnison River, Colorado. University of Utah Anthropological Papers 59 8, 178-189.
Quote from page 183: "The members of this genus were restriced to cold waters at high elevations. The single record is from the highest station collected during the study and appears to support the known distribution pattern."
Conley,JM; Funk,DH and Buchwalter,DB 2009 Selenium bioaccumulation and maternal transfer in the mayfly Centroptilum triangulifer in a life-cycle, periphyton-biofilm trophic assay. Environmental Science and Technology, 43(20)7952-7957. PDF
Abstract: "Selenium contamination in aquatic ecosystems provides management challenges because bioaccumulation in animals is largely a function of dietary exposure, whereas regulatory entities have traditionally focused on direct water to organism interactions. Selenium is known to be readily absorbed by primary producers and can potentially biomagnify in food webs and elicit adverse effects in higher trophic levels. However, selenium bioaccumulation in the invertebrate prey of many predatory animals is poorly understood. Here, we used 75Se (as selenite) as a radiotracer to characterize Se bioaccumulation into natural periphyton biofilms and subsequent dietary and maternal transfer in the mayfly, Centroptilum triangulifer, in a life-cycle assay. On average periphyton biofilms bioconcentrated selenium 1113 (±430)-fold following 7-9 days of exposure to a range of environmentally relevant dissolved concentrations (2.4-13.9 µg L-1). Mayflies grown to adulthood on these diets further biomagnified Se with trophic transfer factors averaging 2.2 (±0.4)-fold in postpartum maternal tissues. Adults then transferred 46.5 (±8.8) % of their body burdens to eggs with an observed reduction in fecundity for mayflies fed on diets greater than ~11 µg g-1. These results suggest that at environmentally feasible dietary Se concentrations insects are potentially affected by Se exposure, and that the current presumption that insects are simply conduits of Se to higher trophic levels is inaccurate."
Eaton,AE 1869 On Centroptilum, a new genus of the Ephemeridae. Entomologist's Monthly Magazine 6:131-132.
Wiersema, na and McCafferty,WP 2004 New specific synonyms and records of North American Centroptilum and Procloeon (Ephemeroptera: Baetidae). Entomological News 115(3):121-128. PDF
Xie,L and Buchwalter,DB 2011 Cadmium exposure route affects antioxidant responses in the mayfly Centroptilum triangulifer. Aquatic Toxicology, 105(3-4) 199-205. PDF
Abstract: "Aquatic organisms accumulate metals directly from water and from their diets. Exposure to metals is known to generate oxidative stress in living organisms and this stress may be ameliorated via activation of antioxidant enzymes and non-enzymatic antioxidants. To determine if antioxidant physiology is dependent on Cd exposure route in the mayfly Centroptilum triangulifer, we exposed larvae to environmentally relevant concentrations of Cd from isolated dissolved or dietary exposure routes to achieve comparable tissue concentrations. Dissolved Cd had no effect on the antioxidant enzymes examined. However, dietary Cd significantly suppressed catalase and superoxide dismutase activities, and decreased concentrations of the reduced (active) form of glutathione in C. triangulifer larvae. These findings suggest that dietary Cd is potentially more toxic than aqueously derived Cd in this mayfly. We further examined the effect of dietary Cd tissue loading rates on antioxidant enzyme suppression and found that absolute tissue load appeared more important than loading rate. These results may help explain why insects are routinely unresponsive to dissolved metal exposures in the laboratory, yet highly responsive to metal pollution in nature.
-In the mayfly Centroptilum triangulifer, antioxidant enzymes catalase and superoxide dismutase were suppressed by dietary cadmium (Cd) exposures, but not dissolved exposures.
-Dietary Cd reduced concentrations of active glutathione in whole insect homogenates.
-These findings suggest that diet derived Cd is potentially more toxic than aqueous derived Cd in this mayfly, and may help explain the disconnection between laboratory and field data for aquatic insect responses to trace metal pollution."