The explanation of the Dungeness crab habitat will be broken into two sections.  First, explaining the geographic location of the crab.  Next, more specifically explaining its habitat within the marine environment.Geographic Location of crab Image from Wikipedia Commons

 Geographic Location    

The Cancer magister occurs along the west coast of North America.  It ranges from the Aleutian Islands to central California.  The crab plays a key role in these areas being vital to the commercial fishing industry and the local economies associated with them. 

In the image above the areas in red show the geographic location of the crab.

 Marine Habitat               Image from Alaska Fisheries Science Center http://www.afsc.noaa.gov/kodiak/photo/crabdung.htm

The Cancer magister tends to reside in three main habitat types in intertidal zones: shells, eelgrass, and muddy areas. 


Many Dungeness crabs find the shells of bi-valves and reside in them.  They act as a shelter for many younger crabs because the Dungeness crab is cannibalistic.  Younger crabs must find refuge in shells to prevent from becoming prey to older, bigger, and stronger crabs.  This is the preferred habitat over the others because it provides the most protection from predation.   


The eelgrass provides a safe habitat along with a wide variety of prey organisms for the Cancer magister to consume, making it a quite popular habitat.

Sandy/Muddy Substrates

While some smaller crabs will hide in the mud, this habitat it mostly utilized by larger crabs which do not need as much cover to find preferred food items or other smaller crabs.  The image below shows a juvenile crab trying to burrow in a sandy bottom.Dungeness crab burrowing in a sandy bottom Image from http://www.dfw.state.or.us/mrp/shellfish/commercial/crab_lifehistory.asp

In Conclusion...

The crabs slowly progresses through all different habitats as it grows older.  It first starts as a free swimming larva, then as a juvenile it will reside in a shelled habitat moving into  ell beds as it grows larger, finally inhabiting the muddy substrates not having to fear as much predation.

Next, lets explore the Nutrition of the Dungeness crab.