Contributor Galleries The Atlantic blue crab (also known as the Chesapeake Blue Crab) is a common species along the east coast of the United States and in the Gulf of Mexico and lives as far south as Argentina. Rock crabs are extremely mobile and as a scavenger, do not remain in one spot for very long. 165 feet to 1000 feet (50–300 m) and up to 2,600 feet (800 m) Rock crabs are smaller and prefer shallower, inshore waters ranging from 20 to 1500 feet (6-456 m) and are … Atlantic blue crabs are omnivorous and will eat just about anything that they find, plant or animal, dead or alive. Color: yellowish, closely dotted with dark purplish brown, becoming reddish brown after death. The Atlantic blue crab (also known as the Chesapeake Blue Crab) is a common species along the east coast of the United States and in the Gulf of Mexico and lives as far south as Argentina.
"Cancer irroratus" (On-line), Animal Diversity Web. Tropical to temperate latitudes of the western Atlantic Ocean, Subphylum Crustacea (crabs, shrimps, and relatives), Family Portunidae (swimming crabs). Because oysters feed by filtering algae from the water, they function as a natural filter and improve water that is overloaded with nutrients. Mainly outer continental shelf and beyond, often caught along with lobsters. Ontogeny of Osmoregulation and Salinity Tolerance in Cancer irroratus; Elements of Comparison with C. borealis (Crustacea, Decapoda). Found in all parts of the estuary. However, habitat loss and nutrient loading are some of the larger issues faced by this species. Each season it moves between varying depths. After being continuously fed one of two species they had the capability of noticing the difference in odors exhibited by both species, and expressed a preference for the most familiar one. It is named for its blue color (in life) and is a favorite seafood species throughout its range. Sci., 52: 315-318. Recent surveys imply that populations may be rebounding in some places. Click here or below to download hands-on marine science activities for kids. Larger adult rock crabs were more effective regulators than smaller adult rock crabs. First, soft substrates are more common than rocky habitats in this area, as well as farther south in the crab’s range. This showed that rock crabs are able to detect and respond to prey odors (Ristvey & Rebach, 1999). This species reproduces via internal fertilization, and the females only have to mate once in their lifetime. Its length could reach up to 5.1 inches with 202 g of weight. Can. In their early stages of development rock crabs are hyper-osmoconformers in order to adjust to their surroundings. April 24, 2001 Classification, To cite this page: CANCER IRRORATUS CRAB Atlantic rock crab or peekytoe crab. Before mating commences, both male and female rock crabs moult their shell. Another interesting characteristic of the rock crab is its denitition, or teeth. To increase their chance for survival they remain in shallow water and at the bottom of the ocean floor for protection (Gendron,2001). Minimum depth from Ref. "Northeast Marine Life Slide Show: Atlantic Rock Crab" (On-line). In fact, this was actually a long-held misconception of mine due to the crab’s name, and I was always perplexed at the number of their shells I would find in areas with no rocky habitat nearby. After fertilization females lay their eggs and store them under their stomach for almost a year. [2] These crabs are similar in color to, and overlap in size with, the Jonah crab, Cancer borealis. Cancer irroratus salinity tolerance changes throughout its life cycle. As they become adults they adjust between being osmoconformers in higher saline solutions to being hyper-regulators in less concentrated media. Biol. The depths that they exist at range from deep waters at 2,600ft. Required fields are marked *. Size: Up to 5 inches wide and 3.5 inches long at maturity. In recent decades, populations have declined as a combined result of fishing and several disease outbreaks that have inflicted this species. Lobsters usually consume megalops (tiny rock crabs that have just metamorphsed) or crabs that are still in their larva stage. Smaller crabs with the cephalorthorax width of about 50 mm tend to inhabit muddy or sandy bottoms, while other crabs seem to prefer the rocky bottoms (Gendron, 2001). Your email address will not be published. Rock crabs are among the most common subtidal crabs in Rhode Island. As it gets too big to be contained, it splits open the outer shell, and the new exoskeleton hardens. Materials and methods The first reported specimen of the Atlantic rock crab was found 6 August 2006 in the fjord Hvalfjo¨rður, They are able to adapt to extreme variations in depth. This event for males happens during the winter months to ensure that their shells are completely firm before the fall. Second, where rocky areas do exist, Atlantic rock crabs tend to be outcompeted by more aggressive Jonah crabs.
Cancer borealis - Jonah Crab. Taxon Information During this process, the new exoskeleton can be soft for some time, and the crab is vulnerable to predation. Regulations were created by the Department of Fisheries and Oceans (DFO) to ensure the safety and survival of the species. In comparison, when lobsters were placed around the traps there was also a reduction in catch rates of both the small and large rock crabs.