''Lagis koreni'', commonly known as the trumpet worm, is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of marine
polychaete
Polychaeta () is a paraphyletic class (biology), class of generally marine invertebrate, marine annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that ...
worm found in European waters. It lives within a narrow conical tube made of grains of sand and shell fragments.
[
]
Taxonomy
In 1986, Holthe studied the family Pectinariidae
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 long. The earliest pectina ...
and recognised four subgenera within the genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
'' 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''.
Description
The trumpet worm is about long and relatively broad. The head has two pairs of tentacle
In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...
s 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 chaeta
A chaeta or cheta (from Greek χαίτη “crest, mane, flowing hair"; plural: chaetae) is a chitinous bristle or seta found in annelid worms, (although the term is also frequently used to describe similar structures in other invertebrates suc ...
e 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.[A bristleworm - ''Lagis koreni'' - General information]
''Marine Life Information Network The Marine Life Information Network (MarLIN) is an information system for marine biodiversity for Great Britain and Ireland
Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic O ...
''. Retrieved August 8, 2011. 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 with a biomineralized adhesive substance secreted by specialized glands.
Distribution and habitat
''L. koreni'' is found in the seas bordering northwestern Europe including the Arctic Ocean
The Arctic Ocean is the smallest and shallowest of the world's five major oceans. It spans an area of approximately and is known as the coldest of all the oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, a ...
, the Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...
, the North Sea
The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...
, the Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...
and the Adriatic Sea
The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) to t ...
. It is usually found buried in sand or silty sand in the neritic zone
The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth.
From the point of view of marine biology it forms a relatively stable and well-illuminated ...
.[
]
Biology
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
Foraging is searching for wild food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce. Foraging theory is a branch of behavioral ecology that studies the foraging behavi ...
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
The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projecti ...
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
The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'.
The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...
. 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
A water column is a conceptual column of water from the surface of a sea, river or lake to the bottom sediment.Munson, B.H., Axler, R., Hagley C., Host G., Merrick G., Richards C. (2004).Glossary. ''Water on the Web''. University of Minnesota-D ...
are sometimes drawn into the feeding cavern and ingested.[Sediment processing and selective feeding by ''Pectinaria koreni'' (Polychaeta: Pectinariidae)]
Retrieved August 8, 2011.
It has been found that foraminifera
Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular Ectoplasm (cell biology), ectoplasm for catching food and ot ...
, ciliate
The ciliates are a group of alveolates characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagellum, eukaryotic flagella, but are in general shorter and present in much larger numbers, with a ...
s and small copepod
Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor) ...
s are the main diet of the worm. However it disproportionally favours larger particles including nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...
s, crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...
s and larger foraminifera even though these are too big to be digested. These large particles also include faecal pellets of ''Abra alba
''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.
Des ...
'', a bivalve
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...
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.[
Sexual reproduction takes place in the summer. In a study off the coast of ]Wales
Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the ...
, the worm released sperm
Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, whi ...
in bundles into the water column in May and the ova
, abbreviated as OVA and sometimes as OAV (original animation video), are Japanese animated films and series made specially for release in home video formats without prior showings on television or in theaters, though the first part of an OVA s ...
matured at the same time. The larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
e formed part of the zooplankton
Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...
for a few weeks before undergoing metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...
and settling out in June. The larvae began producing mucus
Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It is ...
tubes while still pelagic
The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...
and on settling, started cementing sand grains on to the opening of the tubes.Coastal marine zooplankton: a practical manual for students
Retrieved August 8, 2011. The young worms grew quickly until the onset of winter, when growth ceased.[
]
Ecology
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
A community is a social unit (a group of living things) with commonality such as place, norms, religion, values, customs, or identity. Communities may share a sense of place situated in a given geographical area (e.g. a country, village, tow ...
include the white furrow shell (''Abra alba
''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.
Des ...
''), the transparent razor shell (''Phaxas pellucidus
''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.
Description
''P. pellucidus' ...
''), the bivalve '' Mysella bidentata'', the serpent star (''Ophiura ophiura
''Ophiura ophiura'' or the serpent star is a species of brittle star in the order Ophiurida. It is typically found on coastal seabeds around northwestern Europe.
Description
''Ophiura ophiura'' has a circular central disc up to 35 mm (1.5 ...
'') and various polychaete worms. It has been found in studies of Liverpool Bay
Liverpool Bay is a bay of the Irish Sea between northeast Wales, Cheshire, Lancashire and Merseyside to the east of the Irish Sea. The bay is a classic example of a region of freshwater influence. Liverpool Bay has historically suffered from red ...
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. Also in these studies, the community was shown to be associated with different habitats
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
.[
The trumpet worm is often eaten by bottom-feeding fish including juvenile ]common dab
The common dab (''Limanda limanda'') is an edible flatfish of the family Pleuronectidae. It is a demersal fish native to shallow seas around Northern Europe, in particular the North Sea, where it lives on sandy bottoms down to depths of about ...
s and plaice
Plaice is a common name for a group of flatfish that comprises four species: the European, American, Alaskan and scale-eye plaice.
Commercially, the most important plaice is the European. The principal commercial flatfish in Europe, it is also ...
.[
]
References
{{Taxonbar, from1=Q58584752, from2=Q2888260
Terebellida
Animals described in 1866