Dungeness Crab

Dungeness crabs have four pairs of armored legs, two claws, and a wide, hard shell. A Dungeness's legs are shorter compared to other commercial crabs and their claws have a distinctive hook. The claws of the crab are used both as defense and to tear apart large food items. The crab uses its smaller appendages to pass the food particles into its mouth. Once inside the crab's stomach, food is further digested by the "gastric mill", a collection of tooth-like structures.

Dungeness are most often found in areas with sandy bottoms but can be found on a wide variety of bottom types. The crabs are found in high density from the intertidal zone to a depth of between 170 and 300 ft (52 and 91 m). Individual Dungeness have been found as deep as 2,624 ft (800 m). Adult Dungeness require water with surface temperatures ranging from 38–65 °F (3–18 °C) and salinity ranging from 11 to 35 practical salinity units (PSU). Larvae are much more sensitive to such environmental conditions as salinity and require temperatures of between 50 and 57 °F (10 and 14 °C).

The typical range of the Dungeness extends from Alaska's Aleutian Islands to Point Conception, near Santa Barbara, California. Occasionally, the crab can be found as far south as Magdalena Bay, Baja California Sur, Mexico.

Mature female crabs generally molt in late spring, although exact timing varies with location. Mating occurs immediately after the female has molted and before the new exoskeleton hardens. Males are able to detect when females are molting, presumably through pheromones although this is not confirmed yet. Each mating season, male crabs may mate with many partners. Upon locating an available female, the male initiates a protective premating embrace that lasts for several days. In this embrace, the female is tucked underneath the male, oriented such that their abdomens touch and their heads face each other. The sperm deposited by the male is stored in the spermatheca and all sperm can be stored for up to two and a half years. This means a female may choose to use older sperm or not to mate at all during a given year.

The Dungeness fishery was started by San Francisco fishermen in 1848. By the early 1900s the fishery had expanded to match the entire range of the crabs. Around this time regulations were put in place to allow only hard-shelled male crabs that were at least 6 in (150 mm) inches at their widest point. Similar regulations are still followed today.