| Ochetostoma erythrogrammon | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Class: | Polychaeta |
| Order: | Echiuroidea |
| Family: | Thalassematidae |
| Genus: | Ochetostoma |
| Species: | O. erythrogrammon |
| Binomial name | |
| Ochetostoma erythrogrammon | |
Ochetostoma erythrogrammon is a species of spoon worm in the family Thalassematidae. It is found in shallow water in the Atlantic Ocean, the Mediterranean Sea, and the Indian and Pacific Oceans, burrowing in soft sediment.
Like other echiurians, O. erythrogrammon is very mobile and flexible. It consists of a sausage-shaped trunk up to 160 mm (6 in) in length, with reddish longitudinal grooves and a violet-coloured posterior. This is attached to a gutter-like proboscis, a third to three quarters the length of the body, green on its dorsal surface and yellowish on its ventral surface. [2]
Ochetostoma erythrogrammon occurs in the Atlantic Ocean, the Mediterranean Sea, and the Indian and Pacific Oceans. Its typical habitat is beaches of muddy sand where it lives in a burrow it digs in the intertidal zone. [3] Countries from which this spoon worm has been reported in the Indo-Pacific region include Somalia, Mauritius, Malaysia, Indonesia, Vietnam, Hong Kong and Japan. It is also known from the Red Sea, the Mediterranean Sea, South Africa, Bermuda, Bahamas, Venezuela and Brazil. [2]
This spoon worm tunnels into the soft sediment and creates a burrow in which it lives. Digging is performed mostly by the basal region of the proboscis, with the trunk playing little part in the process. [4] The burrow is U-shaped, having a horizontal section 1 cm (0.4 in) wide and some 25 to 45 cm (10 to 18 in) long, with a vertical or oblique section about 20 cm (8 in) long at either end. The proboscis can be extended through an entrance just 3 mm (0.12 in) wide while the other end of the tube is plugged with mud or sand. [3]
Feeding takes place shortly after the tide retreats while the sediment is still wet. The proboscis is extended like a scoop, first scraping up the sediment and detritus close to the burrow entrance and ingesting it, and then extending with the tip moving progressively farther away. The proboscis becomes thinner and narrower as it lengthens and may reach 25 cm (10 in) in length. The dorsal surface of the proboscis is pressed against the wet sediment, and sand and debris particles are coated with mucus and moved by cilia along the grooved, ventral surface to the mouth. Large particles are discarded. The worm can turn round in its burrow and search for food through what was the rear entrance of the burrow. If disturbed the proboscis rapidly retreats into the burrow. [3]
A number of other organisms live inside the burrow as commensals. These include various species of polyclad flatworms, scale worms, bivalve molluscs, gastropod molluscs, pea crabs, snapping shrimps and copepods; several associates can share the burrow with the spoon worm simultaneously. [2]
The Sipuncula or Sipunculida is a class containing about 162 species of unsegmented marine annelid worms. The name Sipuncula is from the genus name Sipunculus, and comes from the Latin siphunculus meaning a "small tube".
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.
The acorn worms or Enteropneusta are a hemichordate class of invertebrates consisting of one order of the same name. The closest non-hemichordate relatives of the Enteropneusta are the echinoderms. There are 111 known species of acorn worm in the world, the main species for research being Saccoglossus kowalevskii. Two families—Harrimaniidae and Ptychoderidae—separated at least 370 million years ago.
Lagis koreni, commonly known as the trumpet worm, is a species of marine polychaete worm found in European waters. It lives within a narrow conical tube made of grains of sand and shell fragments.
Harrimania planktophilus is a marine acorn worm in the family Harrimaniidae. It lives in a burrow in sediment on the sea floor. It is only known from western Canada and was first described by Cameron in 2002. The species name is from the Greek and translates as "lover of plankton".
Listriolobus pelodes is a species of marine spoon worm. It is found in shallow seas in the North East Pacific off the coast of California. It lives in a burrow in soft sediments.
Phyllodoce mucosa is a species of polychaete worm in the family Phyllodocidae. It is found intertidally in both the Pacific and Atlantic Oceans, typically on sandy or muddy seabeds.
Solecurtus strigilatus, also known as the rosy razor clam, is a species of saltwater clam, a marine bivalve mollusc in the family Solecurtidae. This mollusc is a suspension feeder and can burrow with great rapidity to escape predators. It is an unusual bivalve in that its shell valves are too small to contain all the soft tissue, and the animal is unable to retreat into its shell.
Scolelepis squamata is a species of polychaete worm in the family Spionidae. It occurs on the lower shore of coasts on either side of the Atlantic Ocean.
Saccoglossus bromophenolosus is a species of acorn worm occurring in the northwestern Atlantic Ocean and the northeastern Pacific Ocean. It grows to a length of about 20 cm (8 in) and lives in a burrow in soft sediment in the intertidal and subtidal zones. The scientific name refers to 2,4-dibromophenol, a secondary metabolite present in this worm.
Tubulanus superbus, commonly known as the football jersey worm, is a species of ribbon worm in the phylum Nemertea. Found in the northern Atlantic Ocean, the North Sea and the Mediterranean Sea, it occurs from the lower shore down to about 80 m (260 ft), on sand or gravel.
Tubulanus annulatus, commonly known as the football jersey worm, is a species of ribbon worm in the phylum Nemertea. It ranges across the northern Atlantic Ocean, the North Sea and the Mediterranean Sea, being present from the lower shore down to about 40 m (130 ft), on sand, gravel and other habitats.
Cerebratulus marginatus is a proboscis worm in the family Lineidae. This ribbon worm has an Arctic distribution, and in the North Atlantic Ocean ranges as far south as Cape Cod and the Mediterranean Sea while in the Pacific Ocean it extends southwards to California.
Phascolosoma granulatum is a species of peanut worm in the family Phascolosomatidae. It is found in shallow water in the northeastern Atlantic Ocean and the Mediterranean Sea.
Metabonellia is a genus of marine spoon worms in the family Bonelliidae. It is a monotypic genus and Metabonellia haswelli is the only species. It is commonly known as the green spoon worm and is found in shallow waters around Australia.
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.
Echiurus echiurus is a species of spoon worm in the family Echiuridae. It is found in the North Atlantic Ocean and a subspecies is found in Alaska. It burrows into soft sediment and under boulders and stones in muddy places.
Ikeda taenioides is a species of spoon worm in the family Ikedidae. It is native to the northern Pacific Ocean where it is found in the subtidal waters around Japan.
Maxmuelleria lankesteri is a species of spoon worm in the family Bonelliidae. It is found in the North Atlantic Ocean. It burrows into soft sediment on the seabed, mostly in deep water.
Paraleptopentacta elongata is a species of sea cucumber in the family Cucumariidae. It is found in the northeastern Atlantic Ocean and parts of the Mediterranean Sea. It is an infaunal species, occupying a burrow in the seabed, from which its anterior and posterior ends project.