Dungeness Crab
Metacarcinus magister
Summary 4
The Dungeness crab, Metacarcinus magister (formerly Cancer magister), is a species of crab that inhabits eelgrass beds and water bottoms on the west coast of North America. It typically grows to 20 cm (7.9 in) across the carapace and is a popular seafood prized for its sweet and tender flesh. Its common name comes from the port of Dungeness, Washington.
Biology 5
Biology/Natural History: This crab is the largest edible crab from Alaska to California, making this species important for fisheries commercially and economically. There appears to be five subspecies in California alone. The female Dungeness crab can lay up to 2.5 million eggs and can live up to at least 6 years. Females can store sperm received during one mating season and use it during the next season. This species is a carnivore that feeds on more than 40 different species including small clams, oysters, fish, shrimp, worms and according to recent studies even feeds on Velella nematocysts. The larvae of this species is often attached to the bells of jelly fishes and to their tentacles; these larvae feed on the gonozooids, and by doing so gain protection from pelagic fish predators and are transported to juvenile crab habitats nearshore as long as associated with the cnidarian. Dungeness crab larvae feed primarily on zooplankton, however phytoplankton are also eaten. The larvae are crepuscular migrators, being found near the surface at dawn and dusk but deeper in midday and midnight. In springtime, adults of this crab can be found buried in sand or in tidepools, where it can hide and wait for its new shell to harden.
Description 6
A Red-brown to purple carapace with a spine-tipped edge on the front half; contains ten small teeth on the anterolateral margins; tenth tooth is the most prominent. There are no teeth on the posterolateral margins. Width of carapace up to 23 cm. Chelipeds are purple to brownish at the base and the hands are white with purple. The carpus, propodus, and dactyl of the chelae have spiny ridges. This species alone accounts for more than 99 percent of all crab species taken for commercial reasons.
Food habits 7
Cancer magister eat a variety of marine invertebrates and fish. As juveniles, the Dungeness crabs feed on fish, shrimp, molluscs and crustaceans. Adults feed on bivalves, crustaceans and fishes. The crabs are able to open shells by chipping away at them with their heavy pinching claws.
Animal Foods: carrion ; mollusks; aquatic crustaceans; zooplankton
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods)
Habitat 8
Dungeness crabs are found on the Pacific coast in sandy bottoms below the tidal mark. They can also be found at lowtide in sandy or muddy bays where there is a good growth of eel grass. Dungeness crabs are intolerant of low dissolved oxygen conditions. Also, even low amounts of ammonia are toxic to the crabs. Dungeness crabs also tend to grow better in water that is above six degrees Celsius (Kozloff 1973).
Habitat Regions: temperate ; saltwater or marine
Aquatic Biomes: benthic ; coastal ; brackish water
Other Habitat Features: estuarine
Sources and Credits
- (c) hj_west, some rights reserved (CC BY-SA), http://www.flickr.com/photos/hjwest/4852374890/
- (c) Kathryn Arnold, some rights reserved (CC BY-NC), uploaded by Kathryn Arnold
- (c) This picture was taken by Dave Parker ( daveparker01), some rights reserved (CC BY-SA), http://commons.wikimedia.org/wiki/File:Cancer_magister.jpg
- Adapted by Marisa Rafter from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Metacarcinus_magister
- Adapted by Marisa Rafter from a work by (c) Rosario Beach Marine Laboratory, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/10456045
- (c) Rosario Beach Marine Laboratory, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/10456043
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/18637785
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/18637782
