Fauna
Invertebrate

Red Rock Crab

Cancer productus

Also known as Pacific Red Rock Crab, Brick-Red Crab

Red rock crabs patrol rocky Pacific intertidal reefs and subtidal kelp forests, using exceptionally strong, black-tipped pincers to crush thick-shelled barnacles and clams. Juveniles display remarkably varied color patterns ranging from striped to stark white before adopting the solid brick-red coloration of mature adults. Highly territorial and aggressive when cornered, these heavy-bodied scavengers play a crucial role in regulating invertebrate populations along the North American coastline.

MarineCrustaceanIntertidal
Red Rock Crab reference1 / 7
Taollan82; Kirt L. Onthank / CC BY-SA 3.0 · cc-by-sa
—observations
—countries
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Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Key facts
Diet & preyAcorn Barnacles, Blue Mussels, Littleneck Clams
Predators
  • Giant Pacific Octopus
  • Sea Otters
  • Sea Gulls
ThreatsHabitat disturbance, ocean acidification, coastal pollution
HabitatsRocky intertidal, subtidal reefs, kelp beds
Life span5–8 years
Classification
  1. OrderDecapoda
  2. FamilyCancridae
  3. GenusCancer
  4. SpeciesCancer productus
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
Powerful claws can crush shells and cause severe pinches; handle only from the rear carapace.
Why it is dangerous
Powerful, thick pincers generate immense crushing force capable of breaking skin or bruising fingers severely.
How to recognize a risky encounter
Features a wide, heavy brick-red shell with dark black tips on both pincers.
What to do
Approach from behind and firmly grip the back edge of the carapace to stay clear of pincers.
Responsible observation
  • Tidepooling Etiquette: Observe crabs in tidepools without lifting or disturbing rocks that shelter marine life.
  • Safe Handling: Hold the rear carapace between thumb and index finger if handling is necessary.
  • Shell Identification: Look for distinctive black-tipped claws to distinguish from similar crabs.
Related species
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