European Green Crab - Carcinus maenas

From our partners at SERC:

Carcinus maenas, commonly referred to as the European green crab, is a portunid crab native to northern European coastal waters. In the early 1800's, it appeared on the East Coast of the United States where it successfully extended its range as far north as Nova Scotia and as far south as Maryland. Later C. maenas successfully invaded the southern coast of mainland Australia, first reported in the early 1900's, and in 1993 colonized the island state of Tasmania. In 1989, the green crab appeared in San Francisco Bay and proceeded to invade coastal embayments to the north and south.  Japan and South Africa have also been recently invaded by Carcinus, although genetic analyses indicate that these may include some hybrids among two species: C. maenas and C. aestuarii. The possible mechanisms (or vectors) responsible for these green crab invasions include dry ballast, ballast water, transfer with aquaculture species or release of teaching material.

Green crabs are known to be voracious predators, preferring bivalves and other infaunal organisms, but are also known to prey on other species of crabs. Carcinus maenas inhabit a wide variety of habitats and environmental conditions, and appear to be responsible for broadscale changes in invertebrate communities, including commercially important species.  In addition, green crabs may have a myriad of effects in vertebrate and invertebrate populations. Our research focuses on the direct and indirect effects of green crabs on invaded ecosystems.