» Genus Ephemerella (Hendricksons, Sulphurs, PMDs)
11 species (Ephemerella alleni, Ephemerella apopsis, Ephemerella berneri, Ephemerella catawba, Ephemerella consimilis, Ephemerella hispida, Ephemerella maculata, Ephemerella mucronata, Ephemerella nuda, Ephemerella unicornis, Ephemerella verruca)
aren't included.
Common Name
This is page 8 of specimens of Ephemerella. Visit the main Ephemerella page for:
- The behavior and habitat of Ephemerella.
- 37 underwater pictures of Ephemerella.
Pictures of 158 Mayfly Specimens in the Genus Ephemerella:
Specimen Page:1...
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17 Ephemerella dorothea infrequens (Pale Morning Dun) Mayfly Nymph
View 2 PicturesHabitat: Shallow riffle over cobble; approx. 1 ft. deep
Size: 8.5 mm. Mature specimens have been captured as large as 10.5 mm.
Emergence schedule: Variable - starting as early as mid March and lasting as late as early June, depending on the year. Usual duration is at least several weeks or more.
Dun Association: Body is elusive pale creamy yellow w/ orange highlights, cream legs and tails, and dun wings
Specimen status in photo: Preserved
Collection method: Kick net
Comments: Extremely common in samples taken from this location. It's color in life was very close to as depicted in the photo; except for the gradual darkening of the abdominal segments as they progress posteriorly, which has been accentuated somewhat by the effects of preservation. Adult association is based upon capture of this taxon at various stages of emergence including: darkened wingcases, split thoraxic notums, and partially ecloded or ''stillborn (Stillborn: In fly fishing, a stillborn insect is one which got stuck in its nymphal or pupal shuck during emergence and floats helplessly on the surface instead of flying away. It is a specific class of cripple, although it is sometimes used interchangeably with that term.)'' specimens.
Entoman Ephemerella invaria (Sulphur Dun) Mayfly Nymph
View 4 PicturesI looked at this small Ephemerella nymph very carefully under a microscope. It as no abdominal tubercles (
A few (not all) of the abdominal tubercles on this
Ephemerella needhami nymph are circled. They are especially large in this species.
Tubercle: Various peculiar little bumps or projections on an insect. Their character is important for the identification of many kinds of insects, such as the nymphs of Ephemerellidae mayflies.) and 1-banded tibiae (Tibia: A middle segments in the leg of an insect, located between the femur and the tarsus.). I think just a very early instar (Instar: Many invertebrates molt through dozens of progressively larger and better-developed stages as they grow. Each of these stages is known as an instar. Hard-bodied nymphs typically molt through more instars than soft-bodied larvae.) invaria nymph. Ephemerella subvaria (Hendrickson) Mayfly Nymph
View 3 PicturesThis is one of the nymphs I collected doing something very, very strange on March 17th 2004. In the middle of the day, around 2 pm, in the water right around my feet I watched lots of Ephemerella nymphs clumsily swimming up all the way to the surface and then just kind of drifting and wiggling around in the water column. None hatched. They seemed to do it more intensely when the sun was out. It wasn't the time of day for the normal invertebrate drift phenomenon, and as far as I know invertebrate drift doesn't involve this kind of clear effort to swim all the way to the surface. I didn't need a net to catch them, I just reached down into the water and grabbed them with my fingers just below the surface.
The prominent abdominal tubercles (
A few (not all) of the abdominal tubercles on this
Ephemerella needhami nymph are circled. They are especially large in this species.
Tubercle: Various peculiar little bumps or projections on an insect. Their character is important for the identification of many kinds of insects, such as the nymphs of Ephemerellidae mayflies.) aren't quite black, though, and the general color is a dark brown, though I saw nymphs with all Hendrickson color stages behaving strangely. Specimen Page:1...
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