Sea Pens resemble old-fashioned ostrich plume pens when they are fully expanded. They range from pale pink to bright orange in color. Although they may look like plants, these are actually colonies of small cnidarians, a type of marine animal which includes jellies.
These animals feed by spreading their feather-like plumes and filtering out smaller organisms such as plankton. When disturbed, Sea Pens can release large amounts of water from internal canals and quickly contract back into the seafloor where they are almost unnoticeable.
Sea Pens also produce bioluminescence. When stroked or moved by currents, they give off a pale green light.
Sea Pens can be found anchored to the soft ocean bottom from British Columbia to central California. They are typically found in large beds off the Oregon Coast in waters as deep as 225 feet (69 meters).