Invertebrate · GBIF taxon 5175654
Wharf Louse
Ligia exoticaAlso known as Sea Roach, Wharf Roach, Sea Slater
Wharf lice are extremely agile, semi-terrestrial crustaceans that scurry across coastal rocks, docks, and harbour walls just above the waterline. Though they breathe with modified gill-like structures requiring high humidity, they actively avoid prolonged submersion in ocean waves. By feeding on microalgae and decaying organic debris, these swift scavengers play a vital role in cleaning intertidal surfaces.
CrustaceanFast-movingScavenger
1 / 7—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Diet & prey
- Microalgae
- Plant detritus
- Dead organic matter
Predators
- Shorebirds
- Crabs
- Predatory intertidal fish
ThreatsShoreline pollution, coastal urbanization, habitat destruction
HabitatsDocks, wharves, jetties, rocky intertidal shores
Life span1 to 2 years
Size / weightNot available
Classification
- OrderIsopoda
- FamilyLigiidae
- GenusLigia
- SpeciesLigia exotica
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
- Observe quiet approach: Move slowly toward dock pilings or rock crevices, as shadows prompt them to scatter quickly.
- Spot at dusk: Search damp surfaces near the high tide line at evening when they emerge in larger numbers to feed.
Competitor 
Close Relative (c) Gilles San Martin, some rights reserved (CC BY-SA), uploaded by Gilles San Martin · cc-by-sa
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