Invertebrate · GBIF taxon 2227375
Big Water Crayfish
Cambarus robustusAlso known as Robust Crayfish
Thriving in swift-flowing, rocky streams and rivers, the Big Water crayfish spends its days tucked beneath cobble and boulder slabs. Its broad, heavy claws serve as both formidable tools for moving river substrate and powerful defense against stream predators. During nocturnal foraging trips, this benthic crustacean cleans riverbeds by consuming algae, decaying organic matter, and small aquatic invertebrates.
FreshwaterCrustaceanBenthic
—observations
—countries
—peak records
Least ConcernConservation statusIUCN Red List categoriesLCNTVUENCREWEXLeast ConcernRed List categories, explained →
Diet & prey
- Aquatic Insects
- Detritus
- Algae
Predators
- Smallmouth Bass
- Great Blue Heron
- Raccoon
ThreatsSiltation, damming, competition from invasive crayfish
HabitatsFast-flowing rocky streams, gravelly rivers, clear cold creeks
Life span3 to 4 years
Size / weightNot available
Classification
- FamilyCambaridae
- SpeciesCambarus robustus
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Pincer claws can pinch sharply if handled; observe without disturbing stream rocks.
Responsible observation
- Habitat Care: Always return lifted river rocks to their exact position to preserve delicate benthic homes.
- Night Observation: Use a red-filtered flashlight along shallow stream edges at night to spot active foragers.
Invasive Competitor (c) Kristof Zyskowski, some rights reserved (CC BY), uploaded by Kristof Zyskowski · cc-by
Predator USFWS Mountain Prairie / Public domain · cc0
Close Relative Smithsonian Environmental Research Center / CC BY 2.0 · cc-by
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