Species · GBIF taxon 2225819
Sally Lightfoot Crab
Grapsus grapsusAlso known as Red Rock Crab, Moorish Crab
Sally Lightfoot crabs are incredibly agile, brightly colored coastal crustaceans famous for their ability to run in all four directions and leap across gaps between wave-swept volcanic rocks. Adults sport brilliant red, orange, and yellow shells with contrasting blue underbellies, while juveniles are dark and camouflaged to blend in with black basalt. They play a vital ecological role by grazing on algae and acting as cleaners, famously picking ticks off marine iguanas in the Galápagos.
CoastalColorfulAgile
Licensed referenceNosferattus / CC0 · cc0
—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Diet & prey
- Algae
- Barnacles
- Dead fish
Predators
- Herons
- Moray eels
- Octopuses
ThreatsCoastal development, marine pollution, oil spills, and rising sea temperatures
HabitatsRocky intertidal zones, volcanic shores, tide pools, and coastal cliffs
Life spanUp to 10 years
Size / weightNot available
Classification
- FamilyGrapsidae
- SpeciesGrapsus grapsus
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Capable of delivering a painful pinch if handled; observe their antics from a safe distance.
- Why it is dangerous
- Equipped with strong, sharp claws used for scraping algae that can deliver a painful pinch if the crab is grabbed or cornered.
- How to recognize a risky encounter
- Look for brilliant red and orange coloration on a flat, circular shell, often seen skittering rapidly over wet coastal rocks.
- What to do
- Do not attempt to catch or corner them; enjoy watching their rapid jumps and climbing skills from a respectful distance.
Responsible observation
- Watch the tide: Look for them active at low tide when they emerge to graze on exposed, algae-covered rocks.
- Move slowly: They have excellent vision and will quickly leap or hide in crevices if they detect sudden movements.
- Look for symbiosis: In the Galápagos, watch for them climbing directly onto marine iguanas to feed on parasites.
Symbiont (c) patrickc, some rights reserved (CC BY), uploaded by patrickc · cc-by
Close Relative 
Close Relative (c) Abu Hamas, some rights reserved (CC BY-SA), uploaded by Abu Hamas · cc-by-sa
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