Rock Caddisfly vs Small Square-Gilled Mayfly

Side-by-side species comparison

Attribute Rock Caddisfly Small Square-Gilled Mayfly
Scientific Name Goera calcarata Caenis luctuosa
Order Trichoptera Ephemeroptera
Family Goeridae Caenidae
Size 8-12 mm 3-6 mm
Habitat Rivers & Streams Ponds & Lakes
Diet Omnivores Omnivores
Regions Europe Europe
Conservation Least Concern Least Concern

Rock Caddisfly

A caddisfly of limestone streams whose cases incorporate calcareous sand grains and pebble ballast. Larvae scrape algae from rock surfaces.

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Did You Know?

The calcareous case material provides partial camouflage against the pale limestone streambed.

Small Square-Gilled Mayfly

A minute mayfly with distinctive square-shaped gills on its nymphs. Adults swarm in enormous numbers near water at twilight.

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Did You Know?

The enlarged second gill plate acts as a protective cover over the remaining delicate gills.