Invertebrate · GBIF taxon 2225816
Mottled Shore Crab
Pachygrapsus transversusAlso known as Transverse Shore Crab, Mottled Sally Lightfoot
Mottled shore crabs scuttle along intertidal rocks and mangrove roots, gripping slick surfaces firmly with hooked dactyli even under crashing waves. They spend low tides grazing algae from stone with quick, alternating scoops of their spoon-tipped pincers while scavenging organic scraps. Highly vigilant, they immediately vanish into tight crevices or dive into tide pools at the slightest overhead shadow.
IntertidalCrustaceanOmnivorous
—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Diet & prey
- Green algae
- Red algae
- Small invertebrates
Predators
- Herons
- Gulls
- Octopuses
ThreatsCoastal development, shoreline armoring, oil spills, and water pollution
HabitatsRocky intertidal zones, jetties, tide pools, and mangrove roots
Life span2–3 years
Size / weightNot available
Classification
- FamilyGrapsidae
- SpeciesPachygrapsus transversus
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Safe to observe at a normal distance.
Responsible observation
- Tide Pool Etiquette: Step carefully across algae-covered rocks and leave sheltering stones unturned to preserve their microhabitats.
- Observation Timing: Watch rocky jetties during falling tides when individuals emerge from water to scrape algae from stone.
Food Source W.carter / CC0 · cc0
Predator (c) Basar, some rights reserved (CC BY-SA) · cc-by-sa
Close Relative (c) Jerry Kirkhart, some rights reserved (CC BY) · cc-by
Close Relative Nosferattus / CC0 · cc0
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