Crustaceans, Pacific Northwest
The pacific northwest has many areas for sport fishing of Crustaceans, and you will not be disappointed. I love going out to get your own crabs and prawns. I used to go out at low night tides towing a small skiff behind me, clam rake in hand with a flashlight.
When you see a crab scurrying away, you lightly step on it, slid the clam rake under your foot to hold the crab to your foot. You swing your foot over your skiff, holding the crab to it with the rake, then you let the crab fall into the boat. Hand didn’t get wet and the crab did not pinch you.
People often mistake empty Dungeness shells strewn along beaches for dead crabs. Crabs shed and grow new shells regularly as part of their growth process. The old shell splits at the back and along the sides so the crab can back out. The shell the crab leaves behind is an almost intact replica of the crab.
The hermit crab is a land or water-dwelling crustacean. Unlike true crabs, hermit crabs have soft, vulnerable abdomens. For protection from predators, many hermit crabs seek out abandoned shells, usually snail shells to live in.
A hermit crab’s soft body is naturally flexible and can twist easily to fit into the spiral interior of a snail’s shell. When a hermit crab finds one of the proper size, it pulls itself inside, leaving several legs and its head outside the shell. A hermit crab carries the shell wherever it goes. When it outgrows its shell, it finds a larger one to move into. Sometimes, hermit crabs carry other sea creatures on its shell, such as sea anemones. These creatures help camouflage the crabs.
Most adult hermit crabs are from 13 mm to 121 mm long. They live on the seashore in tide pools or on the ocean bottom in deeper water, hermit crabs scavenge their food.
The hermit crab has two pairs of antennae and round eyes on the ends of eye stalks. Hermit crabs have 10 legs, but only 6 legs show. These front 6 legs are known as walking legs. Hermit crabs keep their 4 back legs inside their shell. The back legs are much smaller than the walking legs.
If you look into just about any tidal pool at low tide, you will see these little ones crawling about. They are quite beautiful when they are peeking out from their shells.
At low tide, the Mud Flat Crabs can be found wandering about the island’s mud flats searching for bits of plants or animals to eat. When threatened it will often run to the nearest rock and hide underneath, but if caught it will put up quite a fight with its strong pincers.
Breeding happens in the late spring to early summer, the female crab carries its eggs attached to the underside of its tail using specially designed legs. The babies hatch into the water at high tide and drift off as a member of the plankton. After spending weeks floating about they settle to the bottom where they begin their life.
Great blue herons and crows capture many an unwary crab and even the occasional raccoon will hunt for these delicious creatures as the tide recedes. In rocky areas of Vancouver Island, you will find a close cousin of the mudflat crab called the purple shore crab.
Because mudflat crabs are enclosed in a shell that does not grow, it must molt. This molting takes place about seven times during the first year of life and at a decelerating rate thereafter. An average size of 4 cm across the back is reached at one year of age.
Its body color is usually reddish-brown or tan, with white horizontal bars on the carapace, and distinctive white spots on the first and fifth abdominal segments. At times, juveniles have been observed on muddy bottoms, but adults normally live in rocky crevices and under boulders.
The prawn ranges throughout the northern Pacific from Alaska to San Diego, California, and from the Sea of Japan to Korea Strait.
Breeding occurs in inshore waters from May to August. The males will carry the females under them while mating to stop other crabs from mating with them, sometimes they will do this for hours at a time. Eggs can be laid from October to June, but usually between December and January. Red rocks are born as plankton. They need 3 to 4 months to reach the juvenile stage.
The Northern Kelp Spider Crabs eat algae and kelp, but when these are scarce they may eat barnacles, mussels, and plankton. It, in turn, is eaten by stag horns, sculpins, gulls, cabezon and the sea otter.
The species is sometimes parasitized by barnacles which causes the crabs to be sluggish and to have a brownish mass (the reproductive parts of the barnacle) can sometimes be seen protruding from under the abdomen.
Females can be seen carrying eggs throughout most of the year. The females are absent for several summer months each year, and it is thought that they move to deeper water to lay her eggs. The long legs and claws of these crabs are strong and they can pinch hard quite hard, so be careful when handling them.
A female may lay as many as 84,000 bright orange eggs, which then begin to change color to a deep red as embryonic development ensues. The eggs take about a month to hatch into tiny larvae.
Sometimes you can see them, when they are small, hanging onto kelp as it sways in the current. This is almost hypnotic to observe. When there are a number of them together, it is almost like watching ballet dancers.
These little creatures have been fascinating to me since the first time I saw one, I must have been only 6 or 7 years old and was completely spellbound by them, They such wonders to observe.
Old crab shells may wash in on beaches in large numbers and become the basis for false reports of dead crabs. If a young crab loses a limb, it can regrow it quite quickly as they molt quite often, but older crabs could take years to regrow limbs as they molt less often.
Crustaceans are a wide-ranging group of arthropods that include crayfish, crabs, prawns, shrimp, barnacles, amphipods and isopods. There are several easy ways to identify crustaceans, they have a segmented body and an exoskeleton, their limbs are branched, and they have two pairs of antennae. There are about 42,000 species of crustaceans, they are mostly aquatic and most live in an ocean marine environment. There are only a few species of crustaceans found on land or in freshwater. They are a wonderful and diverse group of animals.