These are

year round

residents of . Burntcoat Head waters. irroratus

Class: Order: Family: Cancidrae : Cancer

Distribution Rock range from Labrador and Newfoundland south They inhabit the Atlantic to Miami, Florida. They are now being reported in Icelandic Ocean and are extensively waters. In Canada they are quite common along the east coast. distributed along North They are abundant in the Gulf of St Lawrence, the Bay of Fundy America’s east coast. and coastal Nova Scotia as well as other areas of the Maritimes.

Habitat Off Nova Scotia and in the Bay of Fundy they are commonly Rock crabs live over a large found in water less than 20m deep, with inshore areas of depths depth range, from well ranging from 5 to 20 m. In its southern-most range this species above the low tide line to as is often found in deeper water. They live on a variety of deep as 790 m. substrate types including rocky and loose material. Some prefer muddy or sandy bottoms, especially smaller crabs.

Food They are opportunistic The diet of juvenile and adult rock also includes scallops, feeders consuming a wide snails, sea urchins, brittle stars, and . Larger adult rock assortment of items crabs are known to prey on small and visa versa, including algae, marine lobsters prey on rock crabs. Larvae are considered omnivorous worms, gastropods, planktivores, feeding on minute particles of various organisms, mussels, and various both and vegetable in content. including hermit crabs. When females moult the new shell takes 2 to 3 months to fully harden. It is during this time mating takes place. Males are both Reproduction attentive and protective towards the soft-shelled female. During This (first) occurs when copulation the male will hold on to the female as he transfers his they have reached a certain sperm to her. He does this throughout the entire mating size with their reproductive sequence. The presence of a seminal receptacle in the female organs well developed. indicates that fertilization may be internal. She releases eggs Females are at a body width from her ovaries which become fertile when coming in contact of 49 mm and males at 62 with his sperm. Egg-laying usually occurs within a few days of mm. Males court females mating. She attaches the eggs to her abdomen and carries them who have recently moulted. around for several months as they further develop. Development Depending upon the Larvae are planktonic in their lifestyle. They live close to female's size the number of the surface, free swimming, and feeding on plankton. eggs produced can range After the larval stage is complete they metamorphose into Zoea from about 45,000 to over tiny crabs which convert to a benthic lifestyle. They drop 500,000. These hatch out down to the seabed and gravitate towards the shoreline. into the water column as They are now in their first instar – a stage of growth in larvae (zoeae). They go young crabs. They will moult in several weeks to a larger through several stages of second instar. Within each succeeding moult the interval growth and development between increases. As juveniles they go through several (moults) until they become instars before reaching adulthood and sexual maturity. In megalopa, the final larval the first two years, both female and male juvenile rock stage and metamorphose crab will grow from 1.4 to 4 cm in carapace width. However, into tiny little crablets. after the second year, males typically grow faster than females.

Characteristics A key identifying characteristic of the rock crab is the set of nine The carapace is a yellow- teeth on each side of the front region of the carapace. These are brown in colour with smooth and look like ridges. Its eyes are purple and crimson round and located on thick short stalks. markings on top and a pale Like most crabs, the rock crab has five yellow underneath. It is pairs of walking legs, the first pair is a broad and oval in shape. set of pincers or claws which are used The surface is smooth in for feeding and defence. comparison to other crabs, Atlantic rock crabs are estimated to live as are the claws. Males grow for up to eight years, and at this age may to a carapace width of 15 weigh as much as 0.25 kg. cm and females to 11 cm. They are farmed at six years of age.

Adaptations These crabs can tolerate a wide range of salinity and Their lifecycle is strongly temperatures, however they do have preferences. temperature dependant. Those in northern habitats have a preference for shallow waters; They are distributed in this includes Canadian populations. They specific patterns with tend to remain inshore. Those in habitats respect to temperature, further south migrate in late spring to salinity, light, gravity, deeper waters. Young crabs up to a pressure, substrate, depth, certain carapace width also prefer to and carapace size. The remain in shallow, less turbulent waters relative effect of with muddy or sandy substrates. Others each factor varies with age prefer rocky bottoms with numerous and time of year. hiding places.

Status/Threats Rock crabs are a major component of the diet of lobsters. They The Department of are a by-catch of fisheries, they are also caught and used Fisheries and Oceans as bait, and are now fished for commercial purposes. Fishery monitor this species. regulations are in place to ensure that crab populations do not Larvae and young crabs are become depleted thus impacting the lobster industry. Guidelines heavily predated by a are in place. There is a legal size allowed variety of organisms for adult males. Females cannot be landed. including lobsters, fish and In lobster fishing areas dockside other crabs. monitoring programs are in effect.

Sightings in Nova Scotia These occur in all coastal areas.