CANCER MAGISTER, DUNGENESS CRAB (AKA: DUNGIES)
Ranging the whole west coast of North America, Dungies can be found throughout the sandy and muddy areas in the shallowest parts of lower estuaries to depths of almost 1,500 feet.
This iconic west coast seafood species are hard-shelled with an oval-shaped carapace, a pair of large claws and four pairs of legs. They grow by molting (shedding) their shell and growing a new, larger one.
Dungies are bottom dwellers who eat bivalves, other crustaceans, marine worms and fish. Live Dungeness crabs usually have a light green or purplish brown shell with a serrated edge that turns red when cooked.
LIFE CYCLE
- Mating – May through August, after mature females have moulted and before exoskeleton hardens.
- Eggs – October or November, fully developed eggs are extruded and fertilized, remaining attached to the female’s abdomen until hatching in late winter. Females are often buried in the sand during this phase of life. Females are relatively inactive during the winter; they do not feed and remain buried in the bottom sediment for much of the time. The eggs hatch late winter/early spring depending on the area and water temperature.
- Larval Phase – a 6 stage process from May to September, five zoeal stages and one megalopa stage takes place. Megalopae settle and metamorphize into post-larval instar. Megalopae larvae often settle out in favourable inshore intertidal and subtidal habitats, which are often estuaries with freshwater input. Zoea larvae can be found in offshore areas in the water column.
- Juveniles – young crabs remain in shallow subtidal or lower intertidal waters and overwinter. They are less than 70 mm in size. They may grow to 120 mm after their first year of life. As the crabs age, they’ll move into progressively deeper waters.
- Life Span – Dungeness crabs may live over 10 years and reach a maximum carapace width of 230 mm and weigh up to 2 kg or 4.5 lbs.
How do you tell the difference between a male and female Dungeness crab?
If you look at a crab’s underside, there’s a flap with a distinct shape called the apron. Female Dungeness crab have a rounded apron while males have a long, pointed apron.
MORE ABOUT DUNGIES
- The collective name for a group of crabs is a cast.
- An adult female can carry upwards of 2.5 million eggs!
- It takes about four years for a male crab to reach the legal size for harvesting.
- Dungeness crab grow by moulting, a process whereby the old shell is shed. The new shell underneath absorbs water and swells to a new size 15-30% larger, and then hardens over a period of several months.
Information sourced from the Canadian Department of Fisheries and Oceans (DFO).