Crabs of Dominica

The Crabs from Dominica span freshwater, coastal, mangrove, beach and fully terrestrial habitats. Common groups include freshwater river crabs, land crabs, ghost crabs, fiddler crabs and swimming crabs. Notable species recorded on the island are the freshwater Cyrique (Guinotia dentata), the Blue Land Crab (Cardisoma guanhumi), the two Caribbean land crabs (Gecarcinus ruricola and Gecarcinus lateralis), beach-dwelling Atlantic Ghost Crab (Ocypode quadrata), mangrove tree crabs (Aratus pisonii), and several fiddler crabs. Field guides and island studies document at least twenty crab species in Dominica.

Dominica’s Representative Crab Species

Below is a concise, fact-checked list of crabs recorded for Dominica, spanning land, freshwater, and coastal species; each entry provides a twenty-five-word note on habitat and use.

• Coenobita clypeatus (Caribbean hermit crab): Terrestrial hermit crab of coastal forests and beaches; shelters in shells, climbs trees, scavenges at night, and occurs islandwide along windward shores and littoral habitats.
• Lithodes manningi (deep-water king crab): Rare, deep-slope anomuran documented off Dominica at several hundred metres; not a fishery species locally, but important as a valuable biodiversity record from bathyal habitats.
• Petrolisthes quadratus (porcelain crab): Small, flat-bodied porcelain crab found on rocky shores and reefs; filter-feeds in surge zones and hides beneath stones, adding to intertidal diversity during low tide.
• Cardisoma guanhumi (blue land crab): Large burrowing land crab of low coastal plains and swamps; digs to the water table, emerges after rain, and supports traditional foodways under licensed seasons.
• Gecarcinus lateralis: Terrestrial land crab of dry coastal slopes and scrub; orange to black carapace, returns to the sea to release larvae, active at dusk and night.
• Gecarcinus ruricola: Highly terrestrial land crab across the Antilles; occupies rocky slopes and dry forest edges, migrates to the coast to spawn, widely valued in local cuisine.
• Geograpsus lividus: Agile grapsid on rocky coasts; scavenges wrack lines, climbs rocks above splash zone, and serves as shoreline nutrient recycler along exposed headlands around Dominica islandwide.
• Goniopsis cruentata: Mangrove and estuary squareback crab; climbs prop roots, grazes algae and detritus, and supports small-scale subsistence harvest in certain coastal communities during open periods legally.
• Grapsus grapsus (Sally Lightfoot crab): Vivid rock crab on wave-battered shores; quick, diurnal forager on algae and carrion, photographed near headlands and sea cliffs including Roseau and Scotts Head promontory.
• Ocypode quadrata (Atlantic ghost crab): Common beach-dwelling crab tunneling in beach sands; nocturnal runner, bioindicator of beach condition, sometimes preys on hatchlings at nesting sites along Atlantic-facing shores in Dominica.
• Uca burgersi (fiddler crab): Small mudflat fiddler; males wave enlarged claw in displays, burrow in intertidal sediments, and oxygenate flats that host microbes and juvenile fishes around mangrove creeks.
• Uca vocator (fiddler crab): Widespread fiddler of sheltered bays and mangrove margins; builds chimneys, feeds on organic films, and responds to tides with synchronized surface activity across northern estuaries.
• Ucides cordatus (mangrove crab): Burrowing mangrove crab; excavates galleries in soft mud, feeds on leaves, stabilizes sediments, and occurs in Dominica’s mangrove patches such as Indian River and creeks.
• Plagusia depressa (sargassum crab): Flattened swimmer clinging to floating Sargassum and rocky ledges; camouflaged, agile, occasionally arriving on rafts along Atlantic coasts, observed during Sargassum influx events islandwide periodically.
• Callinectes bocourti: Swimming crab recorded in coastal waters; similar to other Callinectes, inhabits sandy bottoms and estuaries, targeted with small nets elsewhere in the Caribbean by fishers.
• Callinectes marginatus: Tropical swimming crab of bays and estuaries; fast, laterally swimming predator and scavenger occupying soft-bottom habitats near river mouths in Dominica and adjacent coastal region.
• Callinectes sapidus (Atlantic blue crab): Edible swimming crab with spined carapace and bright blue legs; occurs in Dominican waters and supports small-scale pot and net fisheries regionally in suitable estuaries.
• Guinotia dentata (cyrique): Native freshwater crab of shaded streams and pools; yellow-brown carapace, strong chelae, scavenger and predator, widely known locally as cyrique and consumed traditionally by households.
• Sesarma miersii: Small sesarmid of freshwater creeks and brackish margins; feeds on detritus and algae, contributing to leaf-litter breakdown along riparian corridors in valleys across the island.
• Sesarma robertii: Riparian sesarmid occupying leaf packs and roots; tolerates variable salinity, grazes biofilms, and shelters juvenile shrimp and gobies within lowland streams and mangrove edges locally.
• Cyclograpsus integer: Varunid crab of rocky intertidal crevices; quick-moving scavenger that forages at low tide and retreats as waves surge across exposed platforms around high cliff-backed coasts.

Together these records capture Dominica’s crab diversity from rivers to reefs, informing conservation, harvest rules, and tourism education while highlighting habitats that sustain fisheries, beaches, and mangroves.

Ecology, behavior, and food webs

Dominica’s terrestrial and semi-terrestrial crabs are mostly nocturnal, increasing activity after heavy rains. Studies on the island describe deep Cardisoma burrows near brackish water, widespread Guinotia along river corridors, and Gecarcinus occupying rocky coastal slopes and dry-forest edges. These crabs shape soils, recycle organic matter, and transfer nutrients between land and shore. Local accounts highlight the cyrique’s scavenging role in stream health. On sandy shores, ghost crabs prey on invertebrates and occasionally on turtle hatchlings, a pressure noted widely for this group and managed through guided viewing and beach-protection practices.

Use, cuisine, and culture

Crabs are part of local foodways. A Texas A&M field guide and island study note the popularity of “crab-back” and callaloo-style soups made with terrestrial species, and describe night collecting after rains when crabs leave their burrows. Community knowledge also distinguishes habitats by taste and texture (e.g., river cyrique versus coastal land crabs).

Seasons and regulation

Wild harvest is regulated. Under the Forestry and Wildlife Act, crabs from several families (Portunidae, Pseudothelphusidae, Gecarcinidae, Ocypodidae) may be taken only during a declared open season by licensed hunters. Recent government notices show temporary openings with limits to species, typically crabs, agouti and manicou, over specific fall periods for licence holders.

Conservation links and current issues

Crab habitats intersect with beach management, mangrove protection and river health. No-anchoring rules and mooring use near reefs help protect benthic communities that include swimming crabs; mangrove buffers safeguard Aratus pisonii and juvenile fishes; and beach management reduces lighting, vehicle access and other disturbances that can disrupt ghost crabs and turtle nesting. These measures are part of wider policy under Marine Conservation in Dominica, National Parks and Protected Areas Act, Fisheries Act No. 11 of 1987 and Forestry and Wildlife Act.