Green Crab
Carcinus maenas
This record describes Carcinus maenas (species). Recorded family: Portunidae. Recorded order: Decapoda.
Identification and Appearance
Five short notches along the rim of the carapace. Often found with another invasive species, Hemigrapsus sanguineus .
Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Malacostraca
- Order
- Decapoda (Crabs, Crayfishes, Lobsters, Prawns, and Shrimp)
- Family
- Portunidae (Swimming Crabs)
- Genus
- Carcinus
Imported taxonomy record. Source availability varies; see the source references and editorial policy below.
Habitat and Range
Geographic Range
Native to the northeast Atlantic Ocean and Baltic Sea; now found on both North American coasts, as well as in South America, Australia, and Africa.
About Crabs, Crayfishes, Lobsters, Prawns, and Shrimp: the wider group
Order-level background for Decapoda, the group containing Carcinus maenas. Species-specific details appear above.
Group overview
Decapoda includes ~15,000 described species of crabs, lobsters, shrimp, and crayfish. Although primarily marine and freshwater, some species like hermit crabs and coconut crabs are fully terrestrial.
Ecological role of the group
Crayfish are keystone species in freshwater ecosystems, influencing water clarity, sediment dynamics, and plant communities. Hermit crabs play vital roles in nutrient cycling on tropical islands.
Economic and practical significance of the group
The global shrimp industry alone is worth over $45 billion annually. Crayfish are important aquaculture species and invasive crayfish cause ecological damage estimated in the hundreds of millions annually in Europe and North America.
Recorded sources for this group: FAO fisheries statistics, freshwater ecology. Imported estimates may describe particular regions or reporting periods.
Photos of Green Crab (5)
Photo credits: Contributed by Charley Eiseman; Additional contributions by metrioptera
Frequently Asked Questions About Green Crab
What is Green Crab?
Green Crab (Carcinus maenas) is a species in the family Portunidae, within the order Decapoda.
How do you identify Green Crab?
Five short notches along the rim of the carapace.
Where is Green Crab found?
Range: Native to the northeast Atlantic Ocean and Baltic Sea; now found on both North American coasts, as well as in South America, Australia, and Africa.