Ephemeroptera: Heptageniidae of Gunnison County, Colorado
Introduction to Cinygmula McDunnough 1933
Flat headed mayfly, White spotted flathead mayfly, Red Quill
Updated 2 Mar 2022
The immature Cinygmula on the right was captured and photographed from a small tributary of the East River in early June 2007. The white spots on the head and back of abdomen are camouflage against the multi-colored rocks and gravel in the streams and rivers where they live. Notice just below the antenna you can see the corners of the maxillary palps sticking out of the side of their head. No other Heptageniidae in our area has this feature. Adult Cinygmula often have amber colored wings, however the color is lost in ethanol, so it is only useful in live or recently preserved specimens.
Provisional Species List
On this website:
Key for adult male Cinygmula
North American Cinygmula list from Mayfly Central http://www.entm.purdue.edu/entomology/research/mayfly/species.html#GenusCinygmula
Allan,JD 1984 The size composition of invertebrate drift in a Rocky Mountain stream. Oikos, pp.68-76.
Allan,JD 1987 Macroinvertebrate drift in a Rocky Mountain stream. Hydrobiologia 144, 261-268.
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) was 10 times higher at night. 24 hour totals approached 2000 animals/100m³ 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 Cinygmula spp. Adding discharge to the calculation (a stepwise regression) helped predict the number of Cinygmula in the drift.
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.
Balistrieri,LS; Mebane,CA and Schmidt,TS 2020 Time-dependent accumulation of Cd, Co, Cu, Ni, and Zn in mayfly and caddisfly larvae in experimental streams: Metal sensitivity, uptake pathways, and mixture toxicity. Science of the Total Environment, 732. html
Abstract: "Conceptual and quantitative models were developed to assess time-dependent processes in four sequential experimental stream studies that determined abundances of natural communities of mayfly and caddisfly larvae dosed with single metals (Cd, Co, Cu, Ni, Zn) or multiple metals (Cd + Zn, Co + Cu, Cu + Ni, Cu + Zn, Ni + Zn, Cd + Cu + Zn, Co + Cu + Ni, Cu + Ni + Zn). Metal mixtures contained environmentally relevant metal ratios found in mine drainage. Free metal ion concentrations, accumulation of metals by periphyton, and metal uptake by four families of aquatic insect larvae were either measured (Brachycentridae) or predicted (Ephemerellidae, Heptageniidae, Hydropsychidae) using equilibrium and biodynamic models. Toxicity functions, which included metal accumulations by larvae and metal potencies, were linked to abundances of the insect families. Model results indicated that mayflies accumulated more metal than caddisflies and the relative importance of metal uptake by larvae via dissolved or dietary pathways highly depended on metal uptake rate constants for each insect family and concentrations of metals in food and water. For solution compositions in the experimental streams, accumulations of Cd, Cu, and Zn in larvae occurred primarily through dietary uptake, whereas uptake of dissolved metal was more important for Co and Ni accumulations. Cd, Cu, and Ni were major contributors to toxicity in metal mixtures and for metal ratios examined. Our conceptual approach and quantitative results should aid in designing laboratory experiments and field studies that evaluate metal uptake pathways and metal mixture toxicity to aquatic biota."
Brinkman,SF and Johnston,WD 2012 Acute toxicity of zinc to several aquatic species native to the Rocky Mountains. Archives of environmental contamination and toxicology, 62(2), 272-281.
Carlisle,Daren M; Clements,William H 2003 Growth and secondary production of aquatic insects along a gradient of Zn contamination in Rocky Mountain streams. Journal North American Benthological Society 22(4), 582-597. Abstract and entire paper
Clements,WH; Carlisle,DN; Lazorchak,JM; Johnson,PC 2000 Heavy metals structure benthic communities in Colorado mountain streams. Ecological Applications 10(2)626-638. Abstract
Quote from page 632: "In particular, abundance of the mayflies Rhithrogena robusta (Fig. 5b), Cinygmula sp.(Fig. 5c), and Drunella doddsi(Fig. 5d), and the stonefly Sweltsa sp. (Fig. 5e) was significantly lower at medium- and high-metal stations."
Colburn,T 1982a Aquatic insects as measures of trace element presence in water: Cadmium and Molybdenum. Aquatic Toxicology and Hazard Assessment: Fith Conference, ASTM STP 766, J.G. Pearson, R.B. Foster, and W.E. Bishop, Eds., American Society for Testing and Materials, pgs 316-325.
Colburn,T 1982b Measurement of low levels of molybdenum in the environment by using aquatic insects. 29, 422-428.
Finn,DS and Poff,NL 2008 Emergence and flight activity of alpine stream insects in two years with contrasting winter snowpack. Arctic, Antarctic, and Alpine Research 40(4)638-646. PDF
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.
Working in wadeable streams on the Front Range of Colorado, they found C. mimus and 3 other cryptic species of Cinygmula.
Gilpin,BR and Brusven,MA 1970 Food habits and ecology of mayflies of the St. Maries River in Idaho. Melanderia 4:19-40. PDF
Jensen,SL 1966 The Mayflies of Idaho (Ephemeroptera). M.S. Thesis, University of Utah, Utah. 364 p.
This is the key I use to identify adults in our area, we also double check the adult males using Slater and Kondratieff 2004.
Quote from page 151: "The following combinations of charaters serve to distinguish this genus from all other genera of Heptageniidae occurring in Idaho: Adults. (1) Basal segment of the foretarsi of male at least two-thirds as long as the second segment but never equal; (2) forewings usually brown or amber tinted, at least in the basal half, and with basal costal crossveins well developed (Figs. 63-64); (3) penes of male separated to base (Figs 88-93); and (4) subanal plate of female with a well developed V- or U-shaped postero-nedian emargination (Fig 73). Mature nymphs. (1) Three well developed cauudal filaments present; (2) gills on abdominal segments one and seven not enlarged or extending beneath the abdomen, and similar to those on the intermediate segments only smaller; (3) fibrilliform portion of gills absent or reduced to to a few tiny filaments (Fig 82); and (4) front of head distinctly emarginate medially (Fig 76)."
McCafferty,WP; Durfee,RS; Kondratieff,BC 1993 Colorado mayflies (Ephemeroptera): an annotated inventory. Southwestern Naturalist 38 3, 252-274. PDF
Quote from page 259-260, the discussion about Cinygmula par. "There is considerable confusion about the identification of Cinygmula species mainly due to the fact that larvae have not been adequately described and compared. Cinymula par and Cinygmula mimus seem often to be confused(see previous records above). It remains unclear as to what species the many references to Cinygmula sp. that appear in published ecological studies actually refer. However, C. par is apparently a high altitude species (it was taken by Dodds in headwater areas between 10,500 and 11,650 feet) that has been referred to under various epithets (See also Traver, 1935; Ward and Berner, 1980)."
McDunnough J. 1933 The nymph of Cinygma integrum and description of a new heptagenine genus. Canadian Entomologist 65:73-76.
McDunnough describes the genus Cinygmula in this paper.
Peckarsky,BL 1980 Influence of detritus on colonization of stream invertebrates. Canadian Journal of Fisheries and Aquatic Sciences 37, 957-963.
Peckarsky,BL 1983 Biotic interactions or abiotic limitations? A model of lotic community structure. In: Dynamics of Lotic Ecosystems. Eds: Fontaine III,Thomas D; Bartell,Steven M Ann Arbor Science, Ann Arbor, Michigan, 303-323.
Peckarsky,BL 1985 Do predaceous stoneflies and siltation affect the structure of stream insect communities colonizing enclosures? Canadian Journal of Zoology 63, 1519-1530. PDF
Peckarsky,BL 1991a A field test of resource depression by predatory stonefly larvae. Oikos 61 1, 3-10.
Peckarsky,BL 1991b Is there a coevolutionary arms race between predators and prey? A case study with stoneflies and mayflies. Advances in Ecology 1, 167-180.
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."
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. "
Short,RA; Canton,SP and Ward,JV 1980 Detrital processing and associated macroinvertebrates in a Colorado mountain stream. Ecology, 61(4), 727-732. PDF
Cinygmula sp nymphs were found in all 4 of the species used to make leaf packs; alder, willow, aspen and pine.
Slater,J and Kondratieff,BC 2004 A review of the mayfly genus Cinygmula McDunnough (Ephemeroptera: Heptageniidae) in Colorado. Journal of the Kansas Entomological Society 77(2): 121-126.PDF
This is very helpful and required to identify local Cinygmula adult males.
Abstract: "Ten species of the heptagenine mayfly genus Cinygmula are recognized in North America. Two of these species were originally described from Colorado, C. mimus (Eaton) and C. ramaleyi (Dodds). Additionally, C. par (Eaton) and C. tarda (McDunnough) have been reported from the state. The purpose of this paper is to provide comparable descriptions of the adult males of the four species known from Colorado, providing illustrations of the male penes."
Stewart,KW and Szczytko,SW 1983 Drift of Ephemeroptera and Plecoptera in two Colorado rivers. Freshwater Invertebrate Biology. 2(3)117-131. PDF
Stitt,RP Rockwell,RW Legg,DE and Lockwood,JA 2006 Evaluation of Cinygmula (Ephemeroptera: Heptageniidae) drift behavior as an indicator of aqueous copper contamination. Journal of the Kentucky Academy of Science 67(2) 102-108. PDF
Abstract: " We designed an in situ assay for investigating macroinvertebrate drift behavior in response to a point source of environmental pollution. As a model, we used Cinygmula nymphs to assess both the presence and level of copper contamination in a stream that was polluted with effluent from an abandoned copper mine. The study showed that Cinygmula exhibited increased tendency to drift with increased exposure to aqueous copper. Cinygmula drift behavior exhibited graded responses to increasing concentrations of aqueous copper up to and including 78 ppb. The results indicated that a simple yet sensitive in situ bioassay could be used to detect environmentally important levels of copper contamination in Haggarty Creek. " This research was conducted near the Ferris-Haggarty Mine in Carbon County, Wyoming.
Wellnitz,T 2014 Can current velocity mediate trophic cascades in a mountain stream?. Freshwater Biology, 59(11) 2245-2255. PDF
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
Perlodid stonefly enjoying a Spotted Cinygmula for lunch.
Caught and released from the Upper East river 2 Aug 2011.