This

is easily seen in maenas local waters. Class: Order: Family: :Carcinus

Distribution This crab is native to The Green Crab is now dispersed globally. It has colonized European and North both the Atlantic and Pacific coasts of as well as African coasts as far as the the Atlantic coast of South America. It occurs in , in the east, and Hawaii, Sri Lanka and . Iceland and Central It was introduced to the Atlantic coast of North America by the Norway in the north, and is year 1817 and its range now extends from Nova Scotia to one of the most common Virginia. The first occurrence of the on the Pacific coast throughout much of of the U.S. was in 1989 in California and it has expanded its its range. However it is now range to the south, so also to the north into Canada. This an in many expansion is likely to continue in all coastal directions, it is a very other parts of the world. invasive species. They are quite abundant in Nova Scotia.

Habitat It is predominantly a shore C. maenas can live in all types of marine and estuarine habitats, and shallow water species. including those with mud, sand, or rock substrates, submerged It is found on all types of aquatic vegetation, and emergent marsh, although soft bottoms shorelines, from high water are preferred. level to depths of 60 m.

Food Prey items include clams, oysters, mussels, snails, worms, They are predatory feeders barnacles, crabs and other small . Young crabs feed on a wide variety of on small molluscs and barnacles. At the larval stage they feed organisms. on plankton. Female with eggs

Reproduction Mating begins with the After the female moults, copulation occurs. male finding a female who When ready to lay her fertilized eggs she creates has recently or is about to a cavity in the sand and deposits them. She then moult. He may carry her attaches them to her walking legs and carries s around for a few days them around as they develop further. underneath his body.

Development Once at the megalopa stage, they settle out Eggs hatch into free- of the water column to search for a suitable swimming larvae. These area where they can moult into juvenile crabs. develop offshore in several Young crabs travel to the coastal waters stages, from the first (zoeal) where they begin a moulting cycle and life as stage through to the final juvenile crabs. They moult many times growing larval (megalopa) stage. larger as they do. In approximately three years This is their final moult the juvenile crab will become a fully developed before becoming juvenile crab and be able to mate and reproduce. crabs in the intertidal zone. Zoea Freshly moulted tend to be bright or dark green on top, as their common name implies, Characteristics and yellowish on their underside; but over the moult Despite their common cycle their colour changes. The top surface of the shell name these crabs are a is often irregularly blotched with dark areas. variety of colours including Being wider than it is long it is roughly fan-shaped. yellow, orange, and green. The front of the carapace looks serrated with five They grow to a carapace small spines, or teeth located on the front edge of (shell) width of about 8cm the shell behind each and three rounded lobes and length of 6 cm. Size between the . Meegalopa varies geographically. The wide salinity range allows these crabs to survive in the lower salinities found in Adaptations estuaries. The first pair of legs (pereopods) C. maenas is euryhaline, have well developed pincers (chelae). They meaning it can tolerate a can extend these claws behind their backs to wide range of salinities defend against predators. Females can produce up to (from 4 to 52 ‰), and 185,000 eggs at a time. They are very prolific. survive in temperatures of 0 This allows a very wide dispersal of larvae. to 30 °C. The full impact of the green crab in Canada has yet to be determined. They can affect Status/Threats shellfish aquaculture and fishing industries - eel fisheries in They are under no threat particular. In some areas, Fisheries and Oceans Canada (DFO) whatsoever. In many areas distributes nuisance permits to fisherman. Fishermen who have of the world they are these permits can destroy any green crabs they catch in an effort considered a nuisance to reduce the population size. Natural predators include birds, species to fisheries. fish, and other large marine invertebrates.

These are easily seen on shorelines throughout Nova Scotia in Sightings in Nova Scotia the intertidal zones in shallow water.