Fauna
Invertebrate

Spiny Hill Crayfish

Cambarus robustus

Also known as Robust Crayfish, Big Water Crayfish

Spiny Hill Crayfish inhabit fast-flowing, rocky streams and river margins where they shelter beneath flat slabs and large cobble. These stocky crustaceans are aggressive burrowers when water levels drop, though they spend most of their time foraging along open stream beds. Their dark olive-brown body and heavily spined claws make them a dominant invertebrate in cold mountain headwaters.

CrustaceanFreshwaterBenthic
Spiny Hill Crayfish reference1 / 7
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Least ConcernConservation statusIUCN Red List categoriesLCNTVUENCREWEXLeast ConcernRed List categories, explained →
Key facts
Diet & preyAquatic Insect Larvae, Detritus, Aquatic Vegetation
Predators
  • Smallmouth Bass
  • Raccoons
  • Great Blue Herons
ThreatsInvasive crayfish species, stream siltation, water pollution
HabitatsFast-flowing rocky streams, stony river beds, cold headwaters
Life span3–5 years
Classification
  1. FamilyCambaridae
  2. SpeciesCambarus robustus
Range & activity
Range data is not available yet.
Safe observation
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Capable of delivering a painful pinch with large claws; observe without handling directly.
Why it is dangerous
Equipped with powerful pincers capable of delivering a painful pinch if pinched or mishandled.
How to recognize a risky encounter
Recognized by a dark olive-green carapace and broad, heavy pincers covered in rough bumps and spines.
What to do
Observe quietly in stream bed; if moving for inspection, grip gently behind the pincers on the carapace.
Responsible observation
  • Finding them: Turn over flat submerged stones in clear, swift currents during daytime.
  • Handling caution: Keep hands clear of the large front pincers to prevent a hard pinch.
  • Habitat care: Always return overturned rocks to their original placement to preserve microhabitats.
Related species
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