Dungeness
Crab
The
Dungeness Crab or Cancer magister
got its common name from the town of Dungeness, Washington, now called
Old Town Dungeness, where the first commercial harvesting of the crab
was
done. The Dungeness Crab was the first shellfish harvested commercially
on the North Pacific Coast.
The
Dungeness Crab inhabits eel-grass
beds and muddy to sandy bottoms, from the low inter-tidal zone to
depths
in excess of 600 ft. They range from the Aleutian Islands in Alaska to
south of San Francisco.
Dungeness
crabs are crustaceans, a group of animals that also include
shrimps, lobsters, and prawns. Dungeness have a brownish
green carapace with
an off-white to yellow colored under side. The crab possesses a pair of
white-tipped claws
with narrow tips and 4 pairs of walking legs. The carapace of a
Dungeness crab is roughly fan-shaped and relatively smooth compared to
other crabs such as the
spiny Alaskan King Crabs.
Male Dungeness crabs reach legal size at 3 or
4 years of age and weight about 2 to 3 pounds.
Dungeness crabs are estimated to have a life span of 8 to 13 years.
While
crabs measuring 10 inches across the back have been taken off the
Oregon
and Washington coast, they seldom exceed 8 inches and average just
under
7 inches across the width of the shell. The shell is a
brownish
color, (turning it's trademark red when cooked) and the claws are
white-tipped
. The crab you see photographed below on this page is an anomaly - it's
an albino. There is some coloring due to the preservation process but
it
was without color when landed.
The
Dungeness Crab eats a wide variety
of marine forms.
Stomachs
of ocean crabs have been found to contain clams, fish, and crabs, as
well
as other items, including starfish, worms, squid, snails, and eggs from
fish or crabs. The Dungeness Crab is also cannibalistic, a fact which
has
been observed in laboratories and borne out by examination of stomach
contents.
The
Dungeness Crab is also eaten
by quite a few creatures, including fish such as dogfish, hake,
halibut,
ling cod, and wolf eel. The crab is also a favorite food of the octopus
and, of course, the human.
Life Cycle
Dungeness crabs mate from spring to
fall. The mating takes place between hard-bodied males and soft-bodied
females that have just molted (shed their old shell to grow). A male
may mate with many females. Females store the sperm until all the eggs
are fully developed. A large female can carry 2.5 million eggs.
After hatching,
baby crabs are planktonic
(planktons) and swim freely.
It takes from 4 months to 1 year and through 6 stages of
transformations for a crab to reach
the juvenile stage.
Crabs grow by molting, which means
shedding their old shell. Dungeness crabs molt several times during
their first 2 years of life, with males and females growing at the same
pace. After 2 years, moltings are reduced to once a year and females
grow slower than males, resulting in the size difference between the
sexes. During an annual molt, a Dungeness crab grow about 1 inch
in width. Dungeness are soft after molting and can be easily
pierced, so they dig into the sand and hide for several days until
their shells start to harden. An adult crab requires 2 to 3 months for
its shell to completely harden and fill with meat.
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