Marine-crab
Guides
Carcinus maenas
European green crab, green crab, shore crab, green shore crab, European shore crab
Carcinus maenas is a highly invasive littoral crab native to the northeast Atlantic Ocean and Baltic Sea. Listed among the world's 100 worst invasive alien species, it has established populations across temperate coastlines worldwide including North America, Australia, South America, and South Africa. The species exhibits remarkable phenotypic plasticity, with color morphs ranging from green to red that differ in aggression and stress tolerance. Its successful global dispersal occurs through multiple mechanisms including ballast water, ship hull fouling, and aquaculture transfers.