Light Cahill Mayfly vs Small Minnow Mayfly

Side-by-side species comparison

Attribute Light Cahill Mayfly Small Minnow Mayfly
Scientific Name Heptagenia solitaria Callibaetis ferrugineus
Order Ephemeroptera Ephemeroptera
Family Heptageniidae Baetidae
Size 9-13 mm 7-11 mm
Habitat Rivers & Streams Ponds & Lakes
Diet Omnivores Detritivores
Regions North America North America
Conservation Least Concern Least Concern

Light Cahill Mayfly

A pale-colored mayfly highly prized by fly fishers for imitating hatches. Nymphs prefer moderate current over gravel substrates.

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Did You Know?

The Light Cahill dry fly pattern, designed to mimic this species, has been used since the 1880s.

Small Minnow Mayfly

A mottled brown mayfly common in still waters across North America. Nymphs are excellent swimmers that mimic small minnows.

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Did You Know?

It can produce up to three generations per year in warm climates.