Small Square-Gilled Mayfly vs Dark Blue Quill

Side-by-side species comparison

Attribute Small Square-Gilled Mayfly Dark Blue Quill
Scientific Name Caenis luctuosa Paraleptophlebia mollis
Order Ephemeroptera Ephemeroptera
Family Caenidae Leptophlebiidae
Size 3-6 mm 6-9 mm
Habitat Ponds & Lakes Rivers & Streams
Diet Omnivores Detritivores
Regions Europe North America
Conservation Least Concern Least Concern

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.

Dark Blue Quill

A small dusky-winged mayfly of Appalachian headwater streams. Nymphs are slow crawlers among leaf debris in gentle currents.

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Did You Know?

It is one of the earliest mayflies to emerge each spring, sometimes hatching when snow still lines the streambanks.