The United States government is currently undergoing programs in which to slow the growth of green crab populations fearing a shift in biodiversity in many of the nations coastal regions. Several options are being discussed in which to achieve this. One of which includes introducing a barnacle that can sterilize female green crabs, and the egg predator, Carcinonemertes epialti, to limit the number of green crab offspring being produced.(Washington Dept. 1997)
No conservation of the green crab is currently under way.
US Federal List: no special status
Due to the number of shell fish the green crab eats, and the rate at which it is done, the green crab is seen as a large threat to the many of the nations commercial shellfisheries. It is estimated that millions of dollars could be spent and are spent each year to try and thwart the green crabs from destroying a very important industry, and helping to maintain biodiversity in areas poplutlated by the green crab. The green crab also carries a parasitic worm that can infect birds that prey on the crabs. This can have a potentially devastating effect by throwing off the food chain, and on the ecosystem as a whole in these areas. (Washington Sea 1998, Washington Dept.1997, Jaquette 1998, Holden 1997)
The green crab serves no basic benefit to humans.
The green crab enjoys a variety of different foods. These foods include clams, oysters, mussels, and other small crabs. The green crab is very dexterous and has many ways in which to open up the shellfish on which it feeds. The green crab is known as a very vicious carnivore that will consume anything it can get its claws on.(Holden 1997, Washington Dept. 1997)
The green crab is native to the Atlantic Ocean off of the coast of Europe. Around the early eighteen hundreds the green crab was first seen on the Atlantic coast of North America. The crab can now be found from ranging from as far north as Nova Scotia and to the southern state of Virginia. In the late eighties, the crab mysteriously showed up in the San Francisco Bay area, and has since been spotted as far north as Oregon. This crab has also been found in such areas as far reaching as the continent of Australia.(Deegan, et al 1999, Holden 1997)
Biogeographic Regions: atlantic ocean (Native ); pacific ocean (Native )
The green crab resides among tidal marshes, sandflats, and coasts with a rocky terrain. They tend to stay around these areas for protection from predators, and to be close to a readily available food supply.(Holden 1997, Deegan, et al 1999)
Aquatic Biomes: coastal
The name, green crab, can be deceiving. The color of this crab depends on the molting cycle the crab is undergoing. These colors can range from green to orange and even red in some cases. Green crabs are also visibly identifiable by the yellowish spots on the abdomen, which are also accompanied by five small spines also located on the front edge of the shell. The adult green crab only grows to about three inches in width and two inches in length. (Washington Dept 1997, Jaquette 1998)
Other Physical Features: ectothermic ; bilateral symmetry
The mating process of the green crab begins with the seeking out of a recently molted female crab by a male green crab. The female lays eggs which she carries in a pouch underneath her abdomen where the male crab fertilizes them. The female green crab can lay as many as a hundred thousand eggs at one time. Following fertilization, the females then travel to deeper water to more stable water conditions where the eggs begin to develop. Once the eggs have developed into a larvae,or the zoea stage, the larvae then return to the surface waters for about two weeks. Once the larvae have entered the final stage of development or the megalopae stage, the young crabs travel to the coastal waters where they begin a molting cycle and life as a juvenile crab. In approximately three years the juvenile crab will become a fully developed crab and be able to mate and reproduce.(Bamber and Naylor 1997, Washington Dept. 1997)
