Flat-headed Mayfly vs Iron Blue Dun

Side-by-side species comparison

Attribute Flat-headed Mayfly Iron Blue Dun
Scientific Name Epeorus assimilis Baetis muticus
Order Ephemeroptera Ephemeroptera
Family Heptageniidae Baetidae
Size 10-14 mm 5-7 mm
Habitat Rivers & Streams Rivers & Streams
Diet Herbivores Omnivores
Regions Europe Europe
Conservation Least Concern Least Concern

Flat-headed Mayfly

A stream-dwelling mayfly nymph with a flattened body for clinging to rocks in rapids.

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Did You Know?

Its flattened nymph shape allows it to live in the boundary layer of fast currents.

Iron Blue Dun

A small dark mayfly that hatches prolifically on cool overcast days. Nymphs are found clinging to stones in moderate to fast current.

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Did You Know?

Hatches are most prolific during rain and cold snaps, making it a favorite species for wet-weather anglers.