Marine Worms, Pacific Northwest
These worms live all along the Pacific Northwest coast, you can find them free swimming in bays harbors, just above the bottom or living in burrows they have dug in the muck. They wiggle around with the help of leg like flaps, as they search for shrimp and other small animals to eat. Clam worms can deliver a nasty bite when handled so caution should be taken.
These clam worm is an important source of food for bottom feeding fish and crustaceans. Birds will feed on them after spawning and die. They can sometimes be found in large numbers, dead, on the beach.
Other common names for the clam worm are rag worm, mussel worm, pile worm, and sand worm. clam worms vary in length from 2.5 cm to over 15 cm in length, they are commonly brown, bright red, grey or bright green. The head comes armed with sharp retractable jaws. They use these jaws to feed on shrimp and other marine worms.
When they are getting ready to mate, the rear part of the body becomes swollen with either sperm or eggs. The clam worm leaves the sea bottom at night and comes to the shoreline to release the sperm or eggs near the water surface. After fertilization a spherical larva emerges from the egg. They die soon after. One female clam worm can keep more than one million eggs in her body.
For some reason, halibut go nuts over clam worms and will go into a feeding frenzy when the clam worms are spawning. Tells you that if you want big halibut, you should head out to find some clam worms to use as bait. Ling cod are another lover of the clam worm and will devour them on sight.