The Echiura, or spoon worms, are a small group of marine animals. Once treated as a separate phylum, they are now considered to belong to Annelida. Annelids typically have their bodies divided into segments, but echiurans have secondarily lost their segmentation. The majority of echiurans live in burrows in soft sediment in shallow water, but some live in rock crevices or under boulders, and there are also deep sea forms. More than 230 species have been described. Spoon worms are cylindrical, soft-bodied animals usually possessing a non-retractable proboscis which can be rolled into a scoop-shape to feed. In some species the proboscis is ribbon-like, longer than the trunk and may have a forked tip. Spoon worms vary in size from less than a centimetre in length to more than a metre.
Nemertea is a phylum of animals also known as ribbon worms or proboscis worms, consisting of about 1300 known species. Most ribbon worms are very slim, usually only a few millimeters wide, although a few have relatively short but wide bodies. Many have patterns of yellow, orange, red and green coloration. The foregut, stomach and intestine run a little below the midline of the body, the anus is at the tip of the tail, and the mouth is under the front. A little above the gut is the rhynchocoel, a cavity which mostly runs above the midline and ends a little short of the rear of the body. All species have a proboscis which lies in the rhynchocoel when inactive but everts to emerge just above the mouth to capture the animal's prey with venom. A highly extensible muscle in the back of the rhynchocoel pulls the proboscis in when an attack ends. A few species with stubby bodies filter feed and have suckers at the front and back ends, with which they attach to a host.
Edward Flanders Robb Ricketts was an American marine biologist, ecologist, and philosopher. Renowned as the inspiration for the character Doc in John Steinbeck's 1945 novel Cannery Row, Rickett's professional reputation is rooted in Between Pacific Tides (1939), a pioneering study of intertidal ecology. A friend and mentor of Steinbeck, they collaborated on and co-authored the book, Sea of Cortez (1941).
Joel Walker Hedgpeth was a marine biologist, environmentalist and author. He was an expert on the marine arthropods known as sea spiders (Pycnogonida), and on the seashore plant and animal life of southern and northern California; he co-authored Between Pacific Tides, the definitive guide to California intertidal organisms. He was a spokesperson for care for the floral and faunal diversity of the California coastline.
The Serpulidae are a family of sessile, tube-building annelid worms in the class Polychaeta. The members of this family differ from other sabellid tube worms in that they have a specialized operculum that blocks the entrance of their tubes when they withdraw into the tubes. In addition, serpulids secrete tubes of calcium carbonate. Serpulids are the most important biomineralizers among annelids. About 300 species in the family Serpulidae are known, all but one of which live in saline waters. The earliest serpulids are known from the Permian, and possibly the upper Permian south China
Parapinnixa affinis, the California Bay pea crab, is a species of pinnotherid crab endemic to Southern California. It is a small crab that lives commensally in the tube of a tube-dwelling worm. It was one of the first marine crustaceans to be included on the IUCN Red List in 1996.
Marine invertebrates are the invertebrates that live in marine habitats. Invertebrate is a blanket term that includes all animals apart from the vertebrate members of the chordate phylum. Invertebrates lack a vertebral column, and some have evolved a shell or a hard exoskeleton. As on land and in the air, marine invertebrates have a large variety of body plans, and have been categorised into over 30 phyla. They make up most of the macroscopic life in the oceans.
Lajonkairia lajonkairii is an edible species of saltwater clam in the family Veneridae, the Venus clams.
Urticina crassicornis, commonly known as the mottled anemone, the painted anemone or the Christmas anemone, is a large and common intertidal and subtidal species of sea anemone. Its habitat includes a large portion of the coastal areas of the northern hemisphere, mainly polar regions, and it lives a solitary life for up to 80 years. Mottled anemones are similar to Dahlia anemones and both are commonly referred to as northern red anemones.
Canalipalpata, also known as bristle-footed annelids or fan-head worms, is an order of polychaete worms, with 31 families in it including the suborder Sabellida (families Serpulidae and Sabellidae and the Alvinellidae, a family of deep-sea worms associated with hydrothermal vents.
Diodora aspera, also known as the rough keyhole limpet, is a species of sea snail, a marine gastropod mollusk in the family Fissurellidae, the keyhole limpets. Although similar in appearance to a common limpet, it has a hole near the apex of its shell, and is only distantly related. It often has a scaled polychaete worm Arctonoe vittata living inside its shell as a commensal. In the event that it is attacked by a starfish, it extends flaps of mantle to defend itself, and the worm also helps drive the predator away.
"Sea centipede" is a vernacular name that may refer to any of several real, mythological, or cryptozoological marine-dwelling animals, including:
Paraconcavus pacificus, the red-striped acorn barnacle, is a species of balanid barnacle known from subtidal sandy habitats of the outer northeastern Pacific coast, from Baja California north to Monterey Bay. It grows to 35 mm in diameter, with pink longitudinal stripes over white plates, and can be distinguished from other large, pink-striped barnacles in its range by the longitudinal striations across the growth rings of its plates. While it will attach to many different kinds of hard substrate, it shows a preference for attaching to the shells of other organisms, particularly sand dollars.
Phyllochaetopterus prolifica is a species of marine polychaete worms that live in a tube that it constructs. It is native to shallow waters in the eastern Pacific Ocean and forms colonies of tubes on rocks and submerged objects.
Neobernaya spadicea, common name the chestnut cowrie, is a species of sea snail in the cowrie family, Cypraeidae. Chestnut cowries can be found in the eastern Pacific Ocean, from central California to Baja California. The chestnut cowrie has a highly glossy shell due to an enamel that is secreted from its mantle.
Serpula columbiana, variously called the calcareous tubeworm, plume worm, fan worm, limy tube worm and red tube worm, is a species of segmented marine polychaete worm in the family Serpulidae. It is a cosmopolitan species that is found in most seas in the Northern Hemisphere including the Atlantic Ocean, the Pacific Ocean and the Indian Ocean.
Urechis caupo is a species of spoon worm in the family Urechidae, commonly known as the innkeeper echiuran, the fat innkeeper worm, the innkeeper worm, or the penis fish. It is found in shallow water on the west coast of North America, between southern Oregon and Baja California, where it forms a U-shaped burrow in the sediment and feeds on plankton using a mucus net.
Carcinonemertes errans is a ribbon worm in the family Carcinonemertidae. It lives in symbiosis with the Dungeness crab, consuming the crab's developing eggs. In 1980 it was implicated in the collapse of the Dungeness crab fishery in central California.
Themiste hennahi is a species of unsegmented benthic marine worm in the phylum Sipuncula, the peanut worms. It is native to shallow waters on the Pacific coast of North and South America. This worm was first described in 1828 by the British zoologist John Edward Gray as Themiste hennahi, the type specimen having been collected by the Rev. W. Hennah, with the type locality being Peru.
Loimia medusa, commonly known as the spaghetti worm, is an aquatic species of annelids belonging to the family Terebellidae.
