Brushleg Mayfly vs Spiny Crawler Mayfly

Side-by-side species comparison

Attribute Brushleg Mayfly Spiny Crawler Mayfly
Scientific Name Isonychia bicolor Ephemerella subvaria
Order Ephemeroptera Ephemeroptera
Family Isonychiidae Ephemerellidae
Size 12-18 mm 8-12 mm
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Detritivores
Regions North America North America
Conservation Least Concern Least Concern

Brushleg Mayfly

A large, fast-swimming mayfly with forelegs fringed with bristles for filter feeding. Nymphs inhabit swift riffles of large streams and rivers.

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Did You Know?

Unlike most mayflies, nymphs crawl out of water onto rocks to emerge as adults rather than hatching at the surface.

Spiny Crawler Mayfly

A mayfly important to fly anglers and known as the Hendrickson in fishing culture.

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Did You Know?

Its springtime hatch is one of the most anticipated events in fly fishing.