Species Spotlight: Green Crab
The green crab belongs to the phylum, Arthropoda, and to the subphylum, Crustacea. It is a member of the swimming crab family, Portunidae. Green crabs are littoral crabs, meaning they live in the intertidal zone.
The green crab, also known as the green shore crab or the European green crab, is a common invasive species found in our waters. Green crabs were first introduced to North America in the 1800s, likely introduced through the ballast water of ships from Europe. They are rapid reproducers, aggressive hunters, and they outcompete local species for food and habitat.
Green Crab
Carcinus maena
An easy way to identify a green crab is by the 5 spines on either side of the eye.
A green crab crawling along a rock covered in green algae.
Green crabs often hide among shoreline vegetation.
A green crab sitting among the rocks.
Green Crab
Scientific Name: Carcinus maena
Identification: The green crab is green to dark brown in color with small yellow patches, and has green walking legs speckled with black spots. However, green crabs are not always green! The bottom may be orange or red during molting. An easy way to identify a green crab is by the pentagon shaped carapace and 5 spines on either side of the eye. Adult shells can be up to 4 inches across.
Diet: The green crab is a dominant predator in regions it has invaded, feeding on clams, oysters, scallops, mollusks, crustaceans and marine invertebrates. The green crab moves quickly and is capable of adapting. Its skills improve while foraging as it learns where the prime hunting areas are and how to best catch prey.
Habitat: The green crabs native range lies along the Atlantic coast of Europe and northern Africa. In the United States, green crabs are found along the eastern coast from the Gulf of Saint Lawrence to Delaware. They have also been recorded in Australia, Sri Lanka, South Africa, and Hawaii. The green crab is most commonly found in sheltered intertidal and shallow subtidal habitats, usually near the low-tide line and on mud, sand or pebbles.
Find this Species: Here on Long Island, green crabs are very common! Green crabs are most commonly found on rocky shores, cobble beaches, sandflats and tidal marshes. They can often be found near eelgrass beds or other shoreline vegetation.
Interesting Facts: Green crabs tolerate a wide range of salinities and temperatures. They can also survive in some estuarine environments!
Green crabs can live for up to five years!
Green crabs usually mate at the end of summer. A few months after mating, the egg sac appears, which the females carry through winter and spring. Female green crabs can produce up to 185,000 eggs at a time!
Green crab larvae spend most of their first summer going through a series of stages until they reach megalopa. This is when they are mini versions of adult green crabs that still have a tail used for swimming.
The green crab has been listed as one of the "100 worst invasive species." Since the green crab feeds on a variety of commercially important species, it is often blamed for the reduction of soft-shell clams and other bivalves.