Small-headed Stonefly vs Hooked Stonefly

Side-by-side species comparison

Attribute Small-headed Stonefly Hooked Stonefly
Scientific Name Perlodes microcephala Agnetina capitata
Order Plecoptera Plecoptera
Family Perlodidae Perlidae
Size 15-22 mm body 20-30 mm
Habitat Rivers & Streams Rivers & Streams
Diet Predators Predators
Regions Europe Eastern North America
Conservation Least Concern Least Concern

Small-headed Stonefly

A large spring-emerging stonefly found in clean upland rivers. Nymphs are predatory, feeding on mayfly and midge larvae. An important bioindicator species.

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Did You Know?

Nymphs require the cleanest, most oxygen-rich water of any stonefly, making them sensitive pollution indicators.

Hooked Stonefly

A large, patterned stonefly of eastern North American rivers with distinctive hooked anal gills. Nymphs are active nocturnal predators under cobbles.

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Did You Know?

Its nymphs are nocturnal, hiding under rocks by day and actively hunting at night.