Dungeness Crab
The Dungeness crab Metacarcinus magister is common along the West Coast of North America from California up through Alaska. Dungies are "true" crabs (brachyurans) because they have all 10 legs. They are a popular seafood item, and fisheries occur wherever the crab exists. Dungeness crabs hatch larvae in mid-winter, and the postlarvae (megalopa stage) come into estuaries in May in Washington. They settle in shallow eelgrass beds and grow to about 45 mm by November. After two years in the estuaries they move offshore and begin to breed at age 3.
An adult Dungeness crab Metacarcinus magister
A juvenile Dungeness crab
First stage zoea larva of Metacarcinus magister
Dungeness crabs caught in Grays Harbor, Washington, in June, show three years of annual growth. The smallest is age 0+ (1 month post-settlement); larger crabs are age 1+, 2+ and 3+.
Crabs can regenerate lost appendages. At the next molt a limb-bud appears with all of the segments in miniature. It may take three molts to regrow the leg to its normal size.
Dungeness crabs for sale at Pike Place Market, Seattle, WA
Dungeness crabs bury in the sediment in the daytime, showing only slight depressions where near their gill excurrent apertures
Surprise! A Dungeness crab ops out of its hidey-hole
The inside of a crab's stomach contains calcified structures called the gastric mill, with medial and lateral teeth, that are used to grind up food items.
Typical food items in a crab stomach include parts of Crangon shrimp (top), clam shell (bottom), and fish (left).
A juvenile lingcod Ophiodon elongatus from a crab stomach
A crab gauge is used to determine if this Dungeness crab is legal size. The measurement is taken from just in front of the last lateral spines.