| Lagis koreni | |
|---|---|
 | |
| The trumpet worm and its tube. | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Clade: | Pleistoannelida |
| Subclass: | Sedentaria |
| Order: | Terebellida |
| Family: | Pectinariidae |
| Genus: | Lagis |
| Species: | L. koreni |
| Binomial name | |
| Lagis koreni Malmgren, 1866 | |
| Synonyms [1] | |
| |
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. [1]
In 1986, Holthe studied the family Pectinariidae and recognised four subgenera within the genus Pectinaria although he did not justify how he had come to this decision. In further reviews in 1973 and again in 1984, neither Long nor Wolf recognised these subgenera. In 2002, Pat Hutchings and Rachael Peart undertook a further review of the family. Among other findings, they determined that the Pectinaris subgenera should be given full species status. So the species that had been classified as Pectinaria koreni and later as Pectinaria (Lagis) koreni became Lagis koreni. [2]
The trumpet worm is about 5 cm (2 in) long and relatively broad. The head has two pairs of tentacles and two bunches of gleaming golden spines which are used for digging. It also bears an operculum for sealing the tube in which it lives. The anterior fifteen body segments each bear chaetae or bristles, projecting laterally. These grow from a massive base and have six to eight rows of modified hooks and four rows of tiny teeth. The posterior segment is flattened and bears no chaetae. The animal is pale pink and iridescent, with two pairs of red gills and several red blood vessels visible beneath the surface. [3] It lives inside a long, narrow, conical tube composed of a single layer of grains of sand and shell fragments, skilfully cemented together like a mosaic [4] with a biomineralized adhesive substance secreted by specialized glands. [5]
L. koreni is found in the seas bordering northwestern Europe including the Arctic Ocean, the Atlantic Ocean, the North Sea, the Mediterranean Sea and the Adriatic Sea. It is usually found buried in sand or silty sand in the neritic zone. [3]
The cone-shaped tube of L. koreni is open at both ends, with the narrow end level with or slightly above the surface of the sediment. The worm lives head down in this tube and collects sub-surface particles with its tentacles. In the process it excavates a "feeding cavern" and also forages with the tentacles in the surrounding substrate. It is even able to extend its tentacles as far as the interface between the sediment and the water. It passes the particles it collects via a ciliated groove in the tentacles to its mouth. It is a messy feeder and some particles fall off but these are trapped in the feeding cavern and can be consumed later. After processing the mineral grains and organic matter, unconsolidated faeces are ejected at the posterior, narrow end of the tube and are deposited on the sea floor. Some pseudo-faeces are similarly ejected, having been passed up between the worm and the tube. In some fine-grained sediment, the worm also forms a burrow up to the surface from its feeding cavern, actively keeping it open. Because the worm is constantly irrigating its tube by pumping water through it, suspended particles on the sea bed and in the water column are sometimes drawn into the feeding cavern and ingested. [6]
It has been found that foraminifera, ciliates and small copepods are the main diet of the worm. However it disproportionally favours larger particles including nematodes, crustaceans and larger foraminifera even though these are too big to be digested. These large particles also include faecal pellets of Abra alba , a bivalve mollusc, large numbers of which share the same habitat. Any nutritive benefit to the worm of this practice probably depends on the assimilation of organic molecules and microbes adhering to the surface of the pellet or soluble components from inside. The pellets themselves are ejected relatively unchanged. [6]
Sexual reproduction takes place in the summer. In a study off the coast of Wales, the worm released sperm in bundles into the water column in May and the ova matured at the same time. The larvae formed part of the zooplankton for a few weeks before undergoing metamorphosis and settling out in June. [7] The larvae began producing mucus tubes while still pelagic and on settling, started cementing sand grains on to the opening of the tubes. [8] The young worms grew quickly until the onset of winter, when growth ceased. [7]
The trumpet worm is sometimes found at a density of a thousand individuals per square metre, but numbers fluctuate greatly. Species associated with the trumpet worm in a community include the white furrow shell ( Abra alba ), the transparent razor shell ( Phaxas pellucidus ), the bivalve Mysella bidentata , the serpent star ( Ophiura ophiura ) and various polychaete worms. It has been found in studies of Liverpool Bay that in areas where the sediment has been disturbed by dredging and more deposition has occurred, Lagis koreni and Phaxas pellucidus often come to dominate the community. [9] Also in these studies, the community was shown to be associated with different habitats. [9]
The trumpet worm is often eaten by bottom-feeding fish including juvenile common dabs and plaice. [3]
Polychaeta is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. More than 10,000 species are described in this class. Common representatives include the lugworm and the sandworm or clam worm Alitta.
Pectinariidae, or the trumpet worms or ice cream cone worms, are a family of marine polychaete worms that build tubes using grains of sand roughly resembling ice cream cones or trumpets. These structures can be up to 5 centimetres (2 in) long. The earliest pectinariid fossils are known from the Cretaceous.
Sabellidae, or feather duster worms, are a family of marine polychaete tube worms characterized by protruding feathery branchiae. Sabellids build tubes out of a tough, parchment-like exudate, strengthened with sand and bits of shell. Unlike the other sabellids, the genus Glomerula secretes a tube of calcium carbonate instead. Sabellidae can be found in subtidal habitats around the world. Their oldest fossils are known from the Early Jurassic.
Ampharetidae are a family of terebellid "bristle worm". As such, they belong to the order Canalipalpata, one of the three main clades of polychaetes. They appear to be most closely related to the peculiar alvinellids (Alvinellidae) which inhabit the deep sea, and somewhat less closely to the well-known trumpet worms (Pectinariidae). These three appear to form one of the main clades of terebellids.
Cirratulidae is a family of marine polychaete worms. Members of the family are found worldwide, mostly living in mud or rock crevices. Most are deposit feeders, but some graze on algae or are suspension feeders.
Lanice conchilega, commonly known as the sand mason worm, is a species of burrowing marine polychaete worm. It builds a characteristic tube which projects from the seabed, consisting of cemented sand grains and shell fragments with a fringe at the top.
Abra alba, or the white furrow shell, is a species of bivalve mollusc in the family Semelidae. It occurs in the northeastern Atlantic Ocean and the Mediterranean Sea, where it lives on the floor in shallow areas buried in soft sediments.
Phaxas pellucidus, the transparent razor shell, is a species of marine bivalve mollusc in the family Pharidae. It is found buried in the seabed in coastal waters of northwest Europe, often in great numbers.
Oweniidae is a family of marine polychaete worms in the suborder Sabellida. The worms live in tubes made of sand and are selective filter feeders, detritivores and grazers.
Eudistylia polymorpha, the giant feather duster worm, is a species of marine polychaete worm belonging to the family Sabellidae. Its common name is from the crown of tentacles extended when the animal is under water.
Sabellaria spinulosa is a species of marine polychaete worm in the family Sabellariidae, commonly known as the Ross worm. It lives in a tube built of sand, gravel and pieces of shell.
Cerianthus lloydii is a species of tube-dwelling sea anemone in the family Cerianthidae. It is sometimes called the lesser cylinder anemone and is found in shallow seas around the coasts of north west Europe.
Thelepus cincinnatus is a species of polychaete annelids in the family Terebellidae, which can be found inhabiting a tube of secrete on rocks and shells. The worm is widely distributed, and can be found in almost any region of the oceans at depths ranging from 10 to 4000 meters.
Eunice norvegica is an aquatic polychaete worm found in deep water on the seabed of the northern Atlantic Ocean as well as in the Pacific and Indian Oceans. It is a tubeworm and is often associated with deep water corals.
Diopatra cuprea, commonly known as the plumed worm, decorator worm or sometimes ornate worm, is a species of polychaete worm in the family Onuphidae, first described by the French entomologist Louis Augustin Guillaume Bosc in 1802. It is native to the northwestern Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico.
Polydora ciliata is a species of annelid worm in the family Spionidae, commonly known as a bristleworm. It is a burrowing worm and is found in the northeastern Atlantic Ocean and some other parts of the world.
Leucia nivea is a species of polychaete worm, commonly known as a "scale worm", in the family Polynoidae. This species occurs in the northeastern Atlantic Ocean, the North Sea and the Mediterranean Sea.
Poecilochaetus serpens is a species of marine polychaete worm in the family Poecilochaetidae. It is a benthic worm that burrows into soft sediment.
Sternaspis scutata is a species of marine polychaete worm in the family Sternaspidae. It occurs in the Mediterranean Sea and the temperate northeastern Atlantic Ocean. It lives submerged in mud or other soft sediment.
Maldanidae is a family of more than 200 species of marine polychaetes commonly known as bamboo worms or maldanid worms. They belong to the order Capitellida, in the phylum Annelida. They are most closely related to family Arenicolidae, and together form the clade Maldanomorpha.