Ephemeroptera: Baetidae of Gunnison County, ColoradoIntroduction to Baetis
Small Minnow Mayflies, Blue-winged Olive, BWO, Dark Blue QuillLeach 1815
Updated 17 August 2024
Provisional Species List
Introduction
The Baetis nymphs on the right were living in the Gunnison River near McCabe Lane in March of 2007.
Baetis nymphs earn the name "small minnow mayflies" because they swim like a small fish. They are streamlined for agility swimming and drifting in a current. Most are dark brown or black colored as nymphs. Some have white or reddish colors that help identify them as larvae or adults. The adults have blue or clear wings. They are small and delicate relative to other mayflies such as the Flat-headed (Heptageniidae) or Spiny Crawler (Ephemerellidae) at all ages. The photo below is of a recently emerged Baetis subimago photographed in the Cement Creek drainage in July of 2008. You can see the nymphal exuvia or shuck to the right of the subimago.
Notes
The common species; Baetis bicaudatus, Baetis flavistriga, and Baetis tricaudatus were named in the early part of the 20th century. The less common species were named in last 20 years of the century. Baetis taxonomy changed a lot in the 1990s. Many animals are very difficult to identify even with a microscope. More work on various cryptic or high altitude species is continuing today, driven by interest from many top notch taxonomists and the use of genetic analyses. See references and the other species below. You need adults or mature larvae with brown or black colored wing pads to tell these species apart.
Good Links
On this website:
Key to Baetis larvae
Baetidae Introduction
These species used to be included in Baetis, but have been assigned to different genera recently: Acentrella insignificans,
Diphetor hageni,
Plauditus virilis
Other websites:
References
Allan,JD 1987 Macroinvertebrate drift in a Rocky Mountain stream. Hydrobiologia 144, 261-268.
Based at the Rocky Mountain Biological Lab in Gothic, the author studied Cement Creek in Gunnison County during the spring, summer and fall of 1975-1978. He found that drift densities (number of animals per 100 m³) were 10 times higher at night. 24 hour totals approached 2000 animals/m³ in mid-summer down to 500 animals/m³ in the fall. Quote from the abstract: "Ephemeroptera, especially Baetis, dominated the drift." He found that benthic density (number of animals/m² from streambed samples) was the best predictor of 24hr drift rate for Baetis bicaudatus. Adding discharge to the calculation (a stepwise regression) helped predict the number of B. bicaudatus in the drift.
Allan,JD and Feifarek,BP 1989 Distances travelled by drifting mayfly nymphs: factors influencing return to the substrate. Journal of the North American Benthological Society 8 (4) 322-330. PDF
Abstract: "We determined the distance travelled by drifting nymphs of the mayflies Baetis and Cinygmula to add to existing knowledge of factors influencing drift distance, and to investigate the influence of drift-exiting behavior upon drift magnitude and periodicity. Individuals were released into the water column of a trough at 0.5-m intervals above the exit point, and numbers remaining in suspension over each release distance were fit to a previously developed model which describes return to the substrate according to a negative exponential function. Drift distance increased with increasing current velocity (range studied: 5-55 cm/s) and with decreasing body size (range studied: ca. 0.1-1 mg dry wt) according to log-linear functions. At higher velocities (35 and 55 cm/s), nymphs of both species drifted much shorter distances alive than dead, indicating active exiting from the drift. Drift distances of live nymphs scarcely differed between day and night, which contradicts the suggestion that greater drift abundances at night are caused by disorientation in darkness and consequently greater drift distances. Furthermore, comparisons using nymphs collected from the drift vs. the benthos, and subsequently fed or starved, also revealed no effect of treatment on drift distance, counter to expectations if drifting individuals were intrinsically weaker or less healthy than their benthic counterparts. Thus, although behavioral ability to exit the drift clearly exists in a number of invertebrate taxa, neither the occurrence of drift nor its diel periodicity was explainable on the basis of drift exiting behavior."
Allan,JD; Flecker,AS and Kohler,SL 1991 Diel changes in epibenthic activity and gut fullness of some mayfly nymphs. Internationale Vereinigung für theoretische und angewandte Limnologie: Verhandlungen, 24(5), pp.2881-2885.
Abstract: "The position and activity of stream-dwelling invertebrates on the substrate surface have received moderate study under laboratory conditions and only very limited study under natural conditions. A major impetus for such investigations is the presumed relationship between foraging, the position and activity level of individuals, and drift. A common explanation for downstream transport of invertebrates in the water column, which exhibits marked nocturnal peaks in contrast to low levels by day (Waters 1972), is that drift is the result of a behavioral change in the activity of the benthos that leads to an increased propensity for dislodgement by the current (Bishop 1969). The behavioral change is presumed to be a diel cycle in foraging activity, which brings animals to the substrate surface at night. This passive model views drift, and its diel rhythm, as the consequence of a foraging cycle that exposes organisms to the substrate-water column interface primarily after nightfall (Elliott 1967). While the actual cause of drift entry is uncertain, this model emphasizes accidental dislodgement as a principal cause of drift, and requires a diel cycle in organisms' foraging activity and position (surface vs. within the substrate). The goals of the present study were to examine whether two mayfly nymphs (Baetis and Cinygmula), both of which drift by night and utilize stone tops for feeding (Allan et al. 1986), were more prevalent and active on the substrate surface by day or by night, and whether gut fullness exhibited a parallel pattern. In addition, we wished to compare two methods of assessing night activity: cinematography using a low intensity flash (Wiley and Kohler 1981), and visual observations using dim red light (Allan et al. 1986)."
Allan,JD; Flecker,AS and McClintock,NL 1986 Diel epibenthic activity of mayfly nymphs, and its nonconcordance with behavioral drift 1. Limnology and oceanography, 31(5), pp.1057-1065. PDF
Abstract: "Diel changes in the numbers and activity of mayfly (Ephemeroptera) nymphs on the substrate surface in a stony-bottom stream were determined by direct observations, to investigate the relationship between benthic activity and drift. Individuals were viewed through a glass box (0.1 m2 area) at 2-h intervals for 24 h; dim red light was used during darkness. Baetis was relatively unaffected by the presence of the observer, whereas Cinygmula was very easily disturbed. The number of individuals in view, activity per individual, and total activity all were greatest by day and least during the night for both species. Each of these measures was significantly correlated with temperature, which varied 6°-8°C over the diel cycle. Drift activity, in contrast, was strongly nocturnal and generally peaked immediately after nightfall. Because of the clear lack of correspondence between drift and the activity of mayfly nymphs on stone tops, behavioral drift in this system cannot be explained as the passive consequence of foraging."
Allard,M and Moreau,G 1987 Effects of experimental acidification on a lotic macroinvertebrate community. Hydrobiologia, 144, pp.37-49.
Abstract: "A three month experimental acidification was carried out on lotic bottom communities. Experiments were conducted under semi-natural conditions in plasticized wooden channels. Acidified communities (pH 4.0), with or without added aluminum, were compared with a reference community (pH 6.3-6.9). Added aluminum concentrations were respectively 0.2 and 0.4 mg 1-1 in experiments performed in 1982 and 1983. Water chemistry and taxonomic composition of the macroinvertebrate communities were monitored. Under acidified conditions, results were similar, with or without added aluminum. Mean abundances of all groups of organisms were lowered. Mayflies nearly completely disappeared from the acidified channels. The only organism not affected by the acidification was Microtendipes sp. Differences in the organism response were observed: Orthocladiinae (Rheocricotopus, Parametriocnemus, Corynoneura, Thienemanniella, Nanocladius, Cricotopus) and Ephemeroptera (Baetis, Habrophlebia, Habrophlebiodes, Paraleptophlebia, Ephemerella), especially early instars, were very sensitive to low pH, Chironomini and Tanypodinae were much less sensitive, while Tanytarsini were intermediate; Oligochaeta and Nematoda were difficult to classify, their response being different from one year to another. Organisms inhabiting the surface of artificial substrates disappeared very rapidly from the system, while those buried inside had a delayed reaction to acidification. Aluminum which was mainly in the monomeric form was not responsible for community modifications. Direct action of hydrogen ions through a physiological stress seems a more credible explanation. These results, induced by a continuous experimental acidification, suggest that if this small headwater stream undergoes acidification, the resulting invertebrate community will be very simplified, with only resistant species able to cope with the acid conditions."
Ball,SL; Hebert,PDN; Burian,SK; Webb,JM 2005 Biological identification of mayflies (Ephemeroptera) using DNA barcodes. Journal of the North American Benthological Society 24 3, 508-524.
Blackadar,RJ; Baxter,CV; Davis,JM and Harris,HE 2020 Effects of river ice break-up on organic-matter dynamics and feeding ecology of aquatic insects. River Research and Applications, 36(3) 480-491. PDF
Abstract: "Disturbance shapes the structure and function of aquatic communities and ecosystems, but the dynamics of ice are a less studied dimension of the disturbance-regime of rivers. We investigated effects of a river-ice regime on organic-matter dynamics and feeding ecology of aquatic insects. Samples of biofilm and aquatic insects for gut content analysis were collected monthly from Big Creek, a sixth - order tributary of the Middle Fork Salmon River in central Idaho, USA, during winter 2010-2011. Our results indicate that river ice affects both quantity and quality of organic matter available to, and used by, consumers. Specifically, scour from December and February ice break-up events reduced biofilm biomass by one-half and one-third, respectively, whereas quality (chlorophyll-a: ash-free dry mass) increased. Diets of scrapers, Rhithrogena (Heptageniidae) and Bibiocephala (Blephariceridae), collector-gatherers, Baetis (Baetidae), and collector-filterers, Simulium (Simulidae) appeared to follow patterns of organic matter. Following ice break-up events, diets of these taxa had increased proportions of diatom frustules, which are high-quality food resources due to their relatively high nutrient content. Other taxa, such as collector-gatherers, non-Tanypodinae (Chironomidae), and the collector-filterer, Arctopsyche grandis (Hydropsychidae), consistently consumed high proportions of diatom frustules and insect material, respectively, suggesting they were able to feed more selectively throughout winter. Our study indicates that ice regimes in temperate rivers can affect organic-matter dynamics and feeding ecology of aquatic insects, a possibility that deserves additional investigation, particularly in light of potential changes to the ice regimes of rivers with changing climate."
Cain,DJ; Luoma,SN; Wallace,WG 2004 Linking metal bioaccumulation of aquatic insects to their distribution patterns in a mining-impacted river. Environmental Toxicology and Chemistry 23, 1463-1473.
Canton,SP; Cline,LD; Short,R and Ward,JV 1984 The macroinvertebrates and fish of a Colorado stream during a period of fluctuating discharge. Freshwater Biology, 14(3), 311-316. PDF
SUMMARY. 1. During a 2-year study of the fish and macroinvertebrates of a third-order montane stream, a severe drought in the first year resulted in a temporary cessation of surface flow. Flow was continuous during the second year.
2. Some taxa (e.g. Ophiogomphus severus) exhibited higher density during the drought year, others declined in abundance during low flow (e.g. Baetis spp.), whereas a few (e.g. Tricorythodes minutus) appeared unaffected. Total macroinvertebrate density decreased by 50% during the low flow year compared to the normal flow year. Mayflies were most severely affected, but also exhibited the most dramatic recovery.
3. The collector-gatherer functional feeding group was abundant only during the normal flow year, whereas shredders and predators exhibited increased relative abundance during low flow.
4. Fish populations were severely reduced in the low flow year. However, fishes rapidly invaded the area following resumption of normal flow.
Clements,WH; Kiffney,PM 1994b Integrated laboratory and field approach for assessing impacts of heavy metals at the Arkansas River, Colorado. Environmental Toxicology and Chemistry 13, 397-404. Abstract
In contrast to Clements research on the Clinch River in Virginia, this study of the Arkansas River near Leadville, Colorado found no change in the total numbers of aquatic insects above and below the Superfund site California Gulch. They did however note a shift in community structure as metal tolerant taxa (Orthocladiinae midges) replaced intolerant taxa (mayflies). "Benthic communities [below California Gulch] were were dominated by Orthocladiinae chironomids."
They ran chronic toxicity tests with Ceriodaphnia dubia and found significantly lower reproduction in water from the site 6 kilometers below California Gulch in the spring. In the fall the sites above California Gulch and the recovery site 45 km below had significantly worse reproduction.
Studying the concentrations of a few heavy metals in water from the Arkansas River they found: "Considerable seasonal variation in metal concentrations was observed at stations downstream from California Gulch. Levels of Cd, Cu and Zn were 7 to 9 times higher at [the station below California Gulch] in spring than in fall and remained elevated at [the recovery station 45 km below] in spring."
They also looked at bioaccumulation of Cadmium (Cd) Copper (Cu) and Zinc (Zn) in algae and the aquatic macroinvertebrates Baetis spp, Arctopsyche grandis and Rhyacophila in fall and spring. They found lots of variation as always but Baetis metal concentrations were usually higher than the other taxa studied. "Levels of Cd, Cu and Zn in periphyton and benthic macroinvertebrates were significantly elevated at stations downstream from California Gulch in both seasons. "
Corkum LD and Clifford HF 1981 Function of caudal filaments and correlated structures in mayfly nymphs, with special reference to Baetis (Ephemeroptera). Quaestiones Entomologicae 17:129-146. PDF
Courtney,LA and Clements,WH 2000 Sensitivity to acidic pH in benthic invertebrate assemblages with different histories of exposure to metals. Journal of the North American Benthological Society 19 (1) 112-127.Abstract
Dodds,GS 1923 Mayflies from Colorado: descriptions of certain species and notes on others. Transactions of American Entomological Society 69, 93-116.
Dodds described Baetis bicaudatus and Baetis tricaudatus, among other mayfly species in this publication. Quote from page 109 regarding the genus Baetis: "This genus is a difficult one with which to deal. The insects are small and the species hard to distinguish. Characteristics based on coloration seem to be of no use whatever where alcoholic specimens must be used. Other characteristics must be relied upon, preferably structural differences large enough to be readily seen and not subject to great variation. Accordingly in the following notes there are described only a few points, for the imago, chief among them, size, peculiarities of hind wing and male forceps. The nymph is equally difficult, with the added uncertainty of change due to age and phase of molting cycle. Here, the characters that seem to give most useful distinctive characters are size of mature nymph, number and length of cerci, size and form of gill lamellae. The color pattern persists fairly well for a while in alcohol (i.e. arrangement of light and dark areas) and has given confirming evidence. In case of both nymphs and imagos, however, there is no high degree of certainty as to the accuracy of specific lines - the group one calls a species may include more than one species or he may have divided a species by the use of variable characters."
Durfee,R and Kondratieff,BC 1993 Description of adults of Baetis magnus (Ephemeroptera: Baetidae). Entomological News 104 (5) 227-232.
Ellsworth,SD 2000 Influence of substrate size, Cladophora, and caddisfly pupal cases on colonization of macroinvertebrates in Sagehen Creek, California. Western North American Naturalist, pp.311-319. PDF
Abstract: "Colonization of stream macroinvertebrates onto artificial substrates was examined in Sagehen Creek California, during 1993. Substrate size and presence or absence of pupal cases of the caddisfly Anagapetus (Glossosmatidae) were examined as possible influences on macroinvertebrate colonization. Macroinvertebrates were collected from substrates after 60 d of incubation and identified to the lowest feasible taxonomie unit. Dry weight of the filametous green alga Cladophora also was determined for each substrate.
A general linear model indicated a significant positive relationship between both substrate size and presence pupal cases on richness (P < 0.001). There was no significant effect of cases on the E5 evenness index, which supports the passive sampling model as a mechanism giving rise to the effect of cases on richness. A multivariate general linear model indicated a significant positive effect of Anagapetus cases on Micrasema bactro, Epeorus, and Rhyacophila sp and of substrate size on Hydropsyche occidentalis and Epeorus. Neither cases nor substrate size had a significant effect on Cladophora density (P > 0.05). There were significant negative correlations between Cladophora density and both Shannon H' and J' indices. There were significant positive relationships between Cladophora density with Baetis, Simulium, and Chironomidae density. Combined main effects of substrate size, Anagapetus pupal cases, and Cladophora have dynamic influences on this macroinvertebrate fauna. This study demonstrates the complex interplay of biotic abiotic factors that determine macroinvertebrate distribution and abundance in this system."
Flecker,AS and Allan,JD 1988 Flight direction in some Rocky Mountain mayflies (Ephemeroptera), with observations of parasitism. Aquatic Insects 10(1):33-42. PDF
Abstract: " Adult mayflies (Ephemeroptera) were sampled using sticky traps at several locations along a Rocky Mountain stream. Eight genera were collected, of which imagos of Baetis spp and Rhithrogena hageni were most common. Baetis was represented almost exclusively by females and flight direction was significantly in the upstream direction. In R. hageni both males and females were included. Females appeared to fly into clearings or downstream, whereas males showed no directionality, or a downstream bias. This difference in adult flight direction may be partly explainable by the greater amount of downstream drift in Baetis relative to R. hageni. Finally, mermithid nematodes were found to be frequent parasites of Baetis but not of R. hageni causing total absence of eggs in infected females."
Gill,BA; Harrington,RA; Kondratieff,BC; Zamudio,KR; Poff,NL and Funk,WC 2014 Morphological taxonomy, DNA barcoding, and species diversity in southern Rocky Mountain headwater streams. Freshwater Science 33(1) 288-301. PDF
Working in wadeable streams on the Front Range of Colorado, they found 6 species of Baetis; bicaudatus, flavistriga, magnus and three cryptic species identified by DNA barcoding.
Havird,JC; Shah,AA and Chicco,AJ 2020 Powerhouses in the cold: mitochondrial function during thermal acclimation in montane mayflies. Philosophical Transactions of the Royal Society B, 375(1790), p.20190181. PDF
Abstract: "Mitochondria provide the vast majority of cellular energy available to eukaryotes. Therefore, adjustments in mitochondrial function through genetic changes in mitochondrial or nuclear-encoded genes might underlie environmental adaptation. Environmentally induced plasticity in mitochondrial function is also common, especially in response to thermal acclimation in aquatic systems. Here, we examined mitochondrial function in mayfly larvae (Baetis and Drunella spp.) from high and low elevation mountain streams during thermal acclimation to ecologically relevant temperatures. A multi-substrate titration protocol was used to evaluate different respiratory states in isolated mitochondria, along with cytochrome oxidase and citrate synthase activities. In general, maximal mitochondrial respiratory capacity and oxidative phosphorylation coupling efficiency decreased during acclimation to higher temperatures, suggesting montane insects may be especially vulnerable to rapid climate change. Consistent with predictions of the climate variability hypothesis, mitochondria from Baetis collected at a low elevation site with highly variable daily and seasonal temperatures exhibited greater thermal tolerance than Baetis from a high elevation site with comparatively stable temperatures. However, mitochondrial phenotypes were more resilient than whole-organism phenotypes in the face of thermal stress. These results highlight the complex relationships between mitochondrial and organismal genotypes, phenotypes and environmental adaptation."
Hughes,JM; Mather,PB; Hillyer,M; Cleary,C; Peckarsky,B 2003 Genetic structure in a montane mayfly Baetis bicaudatus (Ephemeroptera: Baetidae), from the Rocky Mountains, Colorado. Freshwater Biology (48) 2149-2162.
Jacob,U 2003 Baetis Leach 1815, sensu stricto or sensu lato. A contribution to the genus concept based on species groups with identification keys. Lauterbornia 47: 59-129. [In German, English summary]
Kiffney,PM and Clements,WH 1993 Bioaccumulation of heavy metals by benthic invertebrates at the Arkansas River, Colorado. Environmental Toxicology and Chemistry 12, 1507-1517.
Kiffney,P; Little,E and Clements,W 1997 Influence of ultraviolet-B radiation on the drift response of stream invertebrates. Freshwater Biology, 37(2), 485-492.
Abstract: " 1. Recent studies have shown that ultraviolet (UV) radiation (280-400 nm) has increased by ≈ 8% in temperate regions over the past decade, but little effort has been devoted to understanding the ecological effects on temperate ecosystems. This research examined the effects of artificial ultraviolet-B (UVB; 280-320 nm) radiation on the drift response of immature stream insects in laboratory microcosms.
2. Two experiments involved natural populations of stream invertebrates, collected from the Cache la Poudre River (September 1994) and the Arkansas River (October 1995) in Colorado. UVB lamps were turned on from 10.00 to 14.00 h each day, and drifting animals were collected on days 1, 3, 5 and 7 during the exposure period. Levels of artificial UVB used in these experiments were similar to levels that stream organisms experience during clear, mid-day conditions at Fort Collins, Colorado (longitude 105º30"; latitude 40º35").
3. Drift was significantly higher in microcosms exposed to UVB than in controls and was dominated by Baetis sp. (Ephemeroptera: Baetidae), Trichoptera (caddisflies) and Simulium sp. (Diptera: Simuliidae). The increased drift of some stream invertebrates in UVB-exposed streams may be a behavioural response and/or a result of injury.
4. Stream organisms may be particularly sensitive to predicted increases in UV radiation, because streams are generally shallow with clear water. As a result of this potential sensitivity, we recommend that research be directed to understanding the ecological effects of UV radiation on these habitats. "
Koch,BJ; Hall Jr,RO and Peckarsky,BL 2020 Nonconsumptive effects of Brook Trout predators reduce secondary production of mayfly prey. Freshwater Science, 39(3), pp.549-558. PDF
Abstract: "The nonconsumptive effects of predators on prey include behavioral, physiological, and life-history changes that reduce the risk of predation but have associated energetic or fitness costs to prey individuals and populations. Biologists have documented such changes for a wide array of predator-prey interactions in a variety of ecosystems; however, the energetic cost of nonconsumptive effects to prey populations has rarely been measured directly. Using a reach-scale manipulation of a naturally-fishless stream, we added chemical cues produced by live Brook Trout (Salvelinus fontinalis Mitchill, 1814) to simulate the presence of trout predation risk, and we quantified the impact of nonconsumptive effects on the secondary production of mayfly prey in the stream. The addition of trout chemical cues reduced the secondary production of larval Baetis mayflies in the treatment reach by 17% compared to an upstream, unmanipulated reference reach. This reduction was driven by smaller body size and earlier emergence of mayflies from the reach with added predator cues. The nonconsumptive effects of a predator can consequently reduce the flux of energy through a dominant stream invertebrate by altering individual life-history and development patterns. Furthermore, quantifying the population-level impact of nonconsumptive effects enables understanding the extent to which these widespread predator effects shape food-web dynamics and ecosystem processes."
Leach,WE 1815 Entomology. Brewster's Edinburgh Encyclopaedia 9:57-172.
Describes the genus Baetis for the first time.
Lugo-Ortiz,CR and McCafferty,WP 1998 A new North American genus of Baetidae (Ephemeroptera) and key to Baetis complex genera. Entomological News 109 5, 345-353.
McCafferty,WP 1997 Name adjustments and a new synonym for North American Ephemeroptera species. Entomological News 108 4, 318, 320.
McCafferty,WP; Durfee,RS; Kondratieff,BC 1993 Colorado mayflies (Ephemeroptera): an annotated inventory. Southwestern Naturalist 38 3, 252-274. PDF
McCafferty,WP; Waltz,RD 1990 Revisionary synopsis of the Baetidae (Ephemeroptera) of North and Central America. Transactions of American Entomological Society 116, 769-799. PDF
Abstract: "Considerable nomenclatural revision of the North and Middle American Baetidae has resulted from comprehensive research aimed at formulating a phylogenetic classification. The 17 Nearctic species in Pseudocloeon not previously assigned to Acentrella or Apobaetis are newly placed in Baetis or Barbaetis. Cloeon in the area is restricted to C. cognatum, while two species previously in Cloeon are placed in Centroptilum and nine in Procloeon, a genus considered for the first time in the Nearctic. Definitions of Centroptilum and Procloeon are modified, both now incorporate species with hindwings and species without hindwings, and 19 species are transferred from Centroptilum to Procloeon. Pseudocentroptilum s. auctt. in North America is synonymized with Procloeon. Neocloeon is recognized as a synonym of Centroptilum s. str. and removed from synonymy with Cloeon. Dactylobaetis is placed in synonymy with Camelobaetidius, and all species, including those from South America, are newly combined. Two species of Baetis are transferred to Acerpenna, and two to Fallceon. A checklist includes 154 currently recognized species among 19 genera in the area, and incorporates 21 new species synonyms and 57 new combinations. The names Baetis armillatus and Baetis cinctutus are substituted for Pseudocloeon parvulum and Pseudocloeon cingulatum, respectively, which otherwise attain homonymic status. Regional distributions for each species and abbreviated synonymies since 1976 are annotated to the checklist. Brief discussions of each genus include information on species diagnosis, revisionary bases, status, and needs. A guide to all nomenclatural changes and added taxa since 1976 provides the bibliographic sources of all such information and serves as a ready index to name equivalencies resulting from extensive recent and present revisions."
McIntosh,AR; Peckarsky,BL and Taylor,BW 2004. Predator-induced resource heterogeneity in a stream food web. Ecology 85(8) 2279-2290. Abstract
Meyer,MD and McCafferty,WP 2001 Hagen's small minnow mayfly (Ephemeroptera: Baetidae) in North America. Entomological News 112 4, 255-263.
Monaghan,MT; Spaak,P; Robinson,CT & Ward,JV 2001 Genetic differentiation of Baetis alpinus Pictet (Ephemeroptera: Baetidae) in fragmented alpine streams. Heredity 86 (4),395-403. doi: 10.1046/ j.1365-2540.2001.00843.x http://www.blackwell-synergy.com/links/doi/10.1046/j.1365-2540.2001.00843.x/abs/
Morihara,DK and McCafferty,WP 1979a The Baetis larvae of North America (Ephemeroptera:Baetidae). Transactions of American Entomological Society 105, 139-221. PDF
Morihara,DK and McCafferty,WP 1979b Systematics of the propinquus group of Baetis species (Ephemeroptera: Baetidae). Annals of the Entomological Society of America 72, 130-135. PDF
Peckarsky,BL 1996 Alternative predator avoidance syndromes of stream-dwelling mayfly larvae. Ecology, 77(6), pp.1888-1905. PDF
Abstract: "Experiments were conducted to compare the patterns, mechanisms, and costs of predator avoidance behavior among larvae of five species of mayflies that co-occur with the predatory stoneflies, Megarcys signata and Kogotus modestus in western Colorado streams. Mayfly drift dispersal behavior, use of high vs. low food (periphyton or detritus) patches, microhabitat use, positioning, and activity periodicity were observed in the presence and absence of predators in circular flow-through chambers using natural stream water. Also, distances from predators at which prey initiated escape responses were compared among prey and predator species. Costs of predator avoidance behavior were assessed by measuring short-term (24 h) feeding rates of mayflies in the presence or absence of predatory stoneflies whose mouthparts were immobilized (glued) to prevent feeding. The intensity and associated costs of predator avoidance behavior of mayfly species were consistent with their relative rates of predation by stoneflies. Megarcys consumes overwintering generation Baetis bicaudatus > Epeorus longimanus > Cinygmula = Ephemerella; Kogotus consumes summer generation Baetis > Epeorus deceptivus = Cinygmula; Megarcys eats more mayflies than Kogotus. While Megarcys induced drift by Baetis, Epeorus, and Cinygmula, this disruptive predator avoidance behavior only reduced food intake by Baetis and Epeorus. The morphologically defended mayfly species, Ephemerella, neither showed escape behavior from Megarcys, nor any cost of its antipredatory posturing behavior. Only Baetis responded by drifting from Kogotus. No mayfly species shifted microhabitats or spent less time on high-food patches in the presence of foraging stoneflies. However, predators enhanced the nocturnal periodicity of Baetis drift, which was negligible in the absence of stoneflies as long as food was abundant. Lack of food also caused some microhabitat and periodicity shifts and increased the magnitude of both day and night drift of Baetis. Thus, Baetis took more risks of predation by visual, drift-feeding fish not only in the presence of predatory stoneflies, but also when food was low or they were hungry. All other mayflies were generally nocturnal in their use of rock surfaces, as long as food was abundant. Finally, the distances at which different mayfly species initiated acute escape responses were also consistent with relative rates of predation. This study demonstrates alternative predator avoidance syndromes by mayfly species ranging from an initial investment in constitutive morphological defenses (e.g., Ephemerella) to induced, energetically costly predator avoidance behaviors (e.g., Baetis). Although the costs of Ephemerella's constitutive defense are unknown, experiments show that prey dispersal is the mechanism underlying fecundity costs of induced responses by Baetis to predators, rather than microhabitat shifts to less favorable resources or temporal changes in foraging activity. A conceptual model suggests that contrasting resource acquisition modes may account for the evolution and maintenance of alternative predator avoidance syndromes along a continuum from Baetis (high mobility) to heptageniids (intermediate mobility) to Ephemerella (low mobility). Prey dispersal (swimming) to avoid capture results in reduction of otherwise high fecundity by Baetis, which trades off morphological defense for enhanced ability to acquire resources. Thus, improved foraging efficiency is the selection pressure maintaining the highly mobile life style in Baetis, which increases resource acquisition and fecundity, offsetting the high mortality costs associated with this behavior."
Peckarsky,BL; Encalada,AC and McIntosh, AR 2011 Why do vulnerable mayflies thrive in trout streams? American Entomologist 57(3)152-164.
Peckarsky,BL; Hughes,JM; Mather,PB; Hillyer,M; Encalada,AC 2005 Are populations of mayflies living in adjacent fish and fishless streams genetically differentiated? Freshwater Biology 50(1), 42-51. doi: 10.1111/j.1365-2427.2004.01292.x Abstract
Pennack,RW and Ward,JV 1986 Interstital faunal communities of the hyporheic and adjacent groundwater biotopes of a Colorado mountain stream. Archiv für Hydrobiologie Suppl. 74 3, 356-396.
They found Baetis sp. nymphs in the hyporheic zone of the South Platte river in the Front Range of Colorado at 1863 meters elevation.
Poff,NL; Olden,JD; Viera,NKM; Finn,DS; Simmons,MP; Kondratieff,BC 2006 Functional trait niches of American lotic insects: traits-based ecological applications in light of phylogenetic relationships. Journal of the North American Benthological Society 25 4, 730-755.
Here are the traits for this species from the Appendix:
| Life History |
Voltinism |
Bi or multivoltine - more than 1 generation/yr |
| Development |
Fast Seasonal |
| Synchronization of emergence |
Poorly synchronized |
| Adult life span |
Less than 1 week |
| Adult ability to exit |
Absent |
| Ability to survive dessication |
Absent |
| Mobility |
Female dispersal |
Less than 1km flight before laying eggs |
| Adult flying strength |
Weak - cannot fly into light breeze |
| Occurance in drift |
Abundant (dominant in drift samples) |
| Maximum crawling rate |
Very low - less than 10cm/hour |
| Swimming ability |
Strong |
| Morphology |
Attachment |
None (free ranging) |
| Armoring |
None (soft -bodied forms) |
| Shape |
Streamlined - fusiform |
| Respiration |
Gills |
| Size at maturity |
Small (less than 9mm) |
| Ecology |
Rheophily |
Depositional and erosional |
| Thermal preference |
Cool/Warm eurythermal |
| Habit |
Swim |
| Trophic habit |
Collector-gatherer |
Poff,NL and Ward,JV 1988 Use of occupied Glossosoma verdona (Trichoptera: Glossosomatidae) cases by early instars of Baetis spp.(Ephemeroptera: Baetidae) in a Rocky Mountain stream. Entomological news (USA).
Poff,NL and Ward,JV 1991 Drift responses of benthic invertebrates to experimental streamflow variation in a hydrologically stable stream. Canadian Journal of Fisheries and Aquatic Sciences, 48(10): 1926-1936.
Abstract: Field experiments were conducted in the regulated upper Colorado River to assess drift responses of lotic macroinvertebrates to streamflow manipulations. In each of three seasons, drift was collected in one control and two experimental riffles. On the first day, no flow manipulations occurred. Six hours before sunset on the second day, streamflow was simultaneously reduced and elevated in two experimental riffles with instream diversion structures. Following flow elevation, both mean daily drift density and drift rate generally increased for 13 taxa across all seasons. Flow reductions generally induced elevated drift densities for most taxa, but drift rates declined for some taxa. Patterns of diel drift periodicity were less frequently modified by flow manipulations. Taxa with typical nocturnal peaks in drift activity (Baetis spp., Epeorus longimanus, Triznaka signata) generally maintained this pattern despite some increases in diurnal drift. For a few taxa, modification of diel drift patterns occurred, either as nocturnal decreases following reduced flow (Paraleptophlebia heteronea, Ephemerella infrequens) or as diurnal drift increases in response to either elevated flow (Lepidostoma ormeam, Chironomidae larvae) or reduced flow (Simuliidae). With some exceptions, observed drift responses could be used to suggest active versus passive processes of drift entry.
Robinson,CT and Minshall,GW 1986 Effects of disturbance frequency on stream benthic community structure in relation to canopy cover and season. Journal of the North American Benthological Society, 237-248. PDF
Abstract: " Field experiments were conducted to examine the effects of disturbance frequency on invertebrates and periphyton colonizing bricks in a third order Rocky Mountain (USA) stream. After an initial colonization period (30 days), sets of bricks were turned over at intervals of 0, 3, 9, 27, or 54 days. Invertebrate species richness and density were reduced as disturbance frequency increased. These trends were evident for both seasons (summer and fall) and sites (open vs. closed canopy). Invertebrate species diversity (H') displayed no effect during the fall experiment; however, H' was reduced at high frequencies of disturbance during the summer experiment. Baetis tricaudatus was the most abundant invertebrate on the substrata at both sites and seasons. Alloperla, Baetis, Cinygmula, Chironomidae, Drunella grandis, Hydropsyche, and Seratella tibialis increased in absolute abundances as disturbance frequency decreased. Four other abundant taxa (Capnia, Cleptelmis, Glossosoma, and Isoperla) displayed no clear response to disturbance in either absolute or relative abundances. Species in low abundance tended to colonize only the less frequently disturbed bricks. During both seasons, periphyton biomass increased as disturbance frequency decreased at the open canopy site, while no trend was apparent at the closed canopy site. Periphyton accumulation monitored over time and among treatments revealed that frequent disturbances maintained low standing crops at an open canopy site. These data suggest that disturbance frequency can directly influence the benthic community at the scale of individual rock "islands" by reducing invertebrate richness, total animal density, and periphyton biomass. The effect of disturbance on species diversity (H') was seasonal, further emphasizing the importance of considering seasonality in stream field studies. "
Roline,R 1988 The effects of heavy metals pollution of the upper Arkansas River on the distribution of aquatic macroinvertebrates. Hydrobiologia 160: 3-8.
They sampled the Arkansas River upstream and downstream of mine drainage and clean water inputs in 1979 and 1980. After compositing 3 surber samplers in the field, they identified the macroinvertebrates to genus level and used a diversity index to evaluate the health of the macroinvertebrate community. Higher diversity is better. Diversity decreased downstream of heavy metal pollution from the Leadville Drain and California Gulch and increased downstream of clean water inputs.
Quote from pages 7-8: "The Ephemeropteran, Baetis, was found in general abundance throughout the study reach and was found to be quite tolerant of heavy metals pollution."
Short,RA; Canton,SP and Ward,JV 1980 Detrital processing and associated macroinvertebrates in a Colorado mountain stream. Ecology, 61(4), 727-732. PDF
Baetis nymphs were found in all 4 of the plant species used to make leaf packs; alder, willow, aspen and pine.
Stauffer-Olsen,NJ; O'Grady,PM and Resh,VH 2019 Cytochrome oxidase I sequences from northern and southern California suggest cryptic Baetis (Ephemeroptera: Baetidae) species. Western North American Naturalist, 79(2) 204-218. PDF
The United States Geological Survey (USGS) National Water Quality Assessment Data Warehouse (NAWQA) shows this genus present in Gunnison County. Data as of 1Sep2005
Waltz RD; McCafferty WP. 1987. New genera of Baetidae for some Nearctic species previously in Baetis Leach (Ephemeroptera). Annals of the Entomological Society of America 80:667-670.
Wang,TQ; McCafferty,WP 1996 New diagnostic characters for the mayfly family Baetidae (Ephemeroptera). Entomological News 107 2, 207-212.
Webb,JM; Jacobus,LM and Sullivan,SP 2018 The state of systematics of North American Baetis Leach, 1815 (Ephemeroptera: Baetidae), with recommendations for identification of larvae. Zootaxa, 4394(1), pp.105-127. html
Abstract: "The North American species of Baetis Leach (Ephemeroptera: Baetidae) are reviewed. Nearly one-third of species are either unknown or inadequately described in the larval stage, a fact not reflected in most keys or standard taxonomic efforts for bioassessment, which typically recommend species-level identifications of larvae. Furthermore, our new observations indicate that some previously published stage associations should be viewed as only tentative, and molecular evidence suggests that current species taxonomy does not reflect biological species. In order to acknowledge these deficiencies, but at the same time provide a degree of higher taxonomic resolution beyond the genus level, we recommend a scheme for identifications incorporating previously established species groups and the species complexes and species included within them. Species complexes are proposed for instances when there are either multiple species that cannot be differentiated in the larval stage or when multiple lines of evidence indicate more than one actual species is included in a single species concept. Complexes include B. flavistriga complex (B. flavistriga McDunnough + B. phoebus McDunnough + B. rusticans McDunnough), B. intercalaris complex (B. intercalaris McDunnough), B. vernus complex (B. brunneicolor McDunnough + B. vernus Curtis), B. bicaudatus complex (B. bicaudatus Dodds), B. tricaudatus complex (B. tricaudatus Dodds), and B. piscatoris complex (B. piscatoris Traver + B. palisadi Mayo + B. persecutus McDunnough [=B. persecutor McCafferty n. obj. syn]). A new larval identification key incorporating the B. piscatoris complex is provided."
Wiersema,NA; Nelson,CR; Kuehnl,KF 2004 A new small minnow mayfly (Ephemeroptera: Baetidae) from Utah, USA. Entomological News 115 3, 139-145.
They provide a key for Baetis larvae to species. Abstract: "Baetis moqui, new species, is described from larvae collected from the Escalante Canyon Region of Garfield County in south-central Utah. The new species is unique among North American Baetis in having gill number one highly reduced or absent. Labial morphology and overall setation characteristics indicate a close relationship between B. moqui and the northern California species Baetis alius and the eastern North American species Baetis pluto. An updated key to the North American Baetis larvae is provided. "
Wipfli,MS, Hudson,J and Caouette,J 1998 Influence of salmon carcasses on stream productivity: response of biofilm and benthic macroinvertebrates in southeastern Alaska, U.S.A. Can. J. Fish. Aquat. Sci. 55(6): 1503-1511 Abstract
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