Lagis koreni
Encyclopedia
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 tube made of grains of sand and shell fragments.
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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.
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
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. 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.
, 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
.
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.
It has been found that foraminifera
, ciliate
s and small copepod
s are the main diet of the worm. However it disproportionally favours larger particles including nematode
s, crustacean
s 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.
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 larva
e formed part of the zooplankton
for a few weeks before undergoing metamorphosis
and settling out in June. The larvae began producing mucus
tubes while still pelagic
and on settling, started cementing sand grains on to the opening of the tubes. The young worms grew quickly until the onset of winter, when growth ceased.
include the white furrow shell (Abra alba
), the razor shell (Phaxas pellucidus
), the bivalve (Mysella bidentata), the brittle 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. Also in these studies, the community was shown to be associated with different habitats
.
The trumpet worm is often eaten by bottom-feeding fish including juvenile common dab
s and plaice
.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of marine polychaete
Polychaete
The Polychaeta or polychaetes are a class of annelid worms, generally marine. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. Indeed, polychaetes are sometimes referred to as bristle worms. More than 10,000...
worm found in European waters. It lives within a narrow conical tube tube made of grains of sand and shell fragments.
Taxonomy
Pectinariidae
Pectinariidae, or the trumpet worms or ice cream cone worms, are a family of marine polychaete worms that build sand tubes roughly resembling ice cream cones up to two inches long.-Genera:...
and recognised four subgenera within the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Pectinaria
Pectinaria (worm)
Pectinaria is a genus of sand tube-building annelid fanworms in the family Pectinariidae.-Species:* Pectinaria articulata* Pectinaria australis Ehlers, 1904* Pectinaria belgica * Pectinaria californiensis...
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 2.5 cm (0.984251968503937 in) long and relatively broad. The head has two pairs of tentacleTentacle
A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...
s and two bunches of gleaming golden spines which are used for digging. It also bears an operculum
Operculum
Operculum may refer to:*Operculum , a stiff structure resembling a lid or a small door that opens and closes**Operculum , a lid on the shell of some gastropods**Operculum , a lid on the orifice of some bryozoans...
for sealing the tube in which it lives. The anterior fifteen body segments each bear chaeta
Chaeta
A chaeta or cheta is a chitinous bristle or seta found on an insect, arthropod or annelid worms such as the earthworm, although the term is also frequently used to describe similar structures in other invertebrates. The plural form is chaetae or chetae.In the Polychaeta, they are located on the...
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. 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 OceanArctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...
, the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
, the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...
, the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
and the Adriatic Sea
Adriatic Sea
The Adriatic Sea is a body of water separating the Italian Peninsula from the Balkan peninsula, and the system of the Apennine Mountains from that of the Dinaric Alps and adjacent ranges...
. It is usually found buried in sand or silty sand in the neritic zone
Neritic zone
The neritic zone, also called coastal waters, the coastal ocean or the sublittoral zone, is the part of the ocean extending from the low tide mark to the edge of the continental shelf, with a relatively shallow depth extending to about 200 meters...
.
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 foragesForaging
- Definitions and significance of foraging behavior :Foraging is the act of searching for and exploiting food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce...
with the tentacles in the surrounding substrate
Substrate (biology)
In biology a substrate is the surface a plant or animal lives upon and grows on. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock can be substrate for another animal that lives on top of the algae. See also substrate .-External...
. 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
Cilium
A cilium is an organelle found in eukaryotic cells. Cilia are slender protuberances that project from the much larger cell body....
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.
It has been found that foraminifera
Foraminifera
The Foraminifera , or forams for short, are a large group of amoeboid protists which are among the commonest plankton species. They have reticulating pseudopods, fine strands of cytoplasm that branch and merge to form a dynamic net...
, ciliate
Ciliate
The ciliates are a group of protozoans characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagella but typically shorter and present in much larger numbers with a different undulating pattern than flagella...
s and small copepod
Copepod
Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat. Some species are planktonic , some are benthic , and some continental species may live in limno-terrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests,...
s are the main diet of the worm. However it disproportionally favours larger particles including nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
s, crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
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
Abra alba or the white furrow shell is a species of bivalve mollusc in the Semelidae family. It occurs in the north eastern Atlantic Ocean and the Mediterranean Sea, where it lives on the floor in shallow areas buried in soft sediments....
, a bivalve
Bivalvia
Bivalvia is a taxonomic class of marine and freshwater molluscs. This class includes clams, oysters, mussels, scallops, and many other families of molluscs that have two hinged shells...
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
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
, the worm released sperm
Sperm
The term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...
in bundles into the water column in May and the ova
Ovum
An ovum is a haploid female reproductive cell or gamete. Both animals and embryophytes have ova. The term ovule is used for the young ovum of an animal, as well as the plant structure that carries the female gametophyte and egg cell and develops into a seed after fertilization...
matured at the same time. The larva
Larva
A larva 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...
e formed part of the zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
for a few weeks before undergoing metamorphosis
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation...
and settling out in June. The larvae began producing mucus
Mucus
In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...
tubes while still pelagic
Pelagic zone
Any water in a sea or lake that is not close to the bottom or near to the shore can be said to be in the pelagic zone. The word pelagic comes from the Greek πέλαγος or pélagos, which means "open sea". The pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes...
and on settling, started cementing sand grains on to the opening of the tubes. 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 communityCommunity (ecology)
In ecology, a community is an assemblage of two or more populations of different species occupying the same geographical area. The term community has a variety of uses...
include the white furrow shell (Abra alba
Abra alba
Abra alba or the white furrow shell is a species of bivalve mollusc in the Semelidae family. It occurs in the north eastern Atlantic Ocean and the Mediterranean Sea, where it lives on the floor in shallow areas buried in soft sediments....
), the razor shell (Phaxas pellucidus
Phaxas pellucidus
Phaxas pellucidus or 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:...
), the bivalve (Mysella bidentata), the brittle star (Ophiura ophiura
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:...
) and various polychaete worms. It has been found in studies of Liverpool Bay
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...
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
Biotope
Biotope is an area of uniform environmental conditions providing a living place for a specific assemblage of plants and animals. Biotope is almost synonymous with the term habitat, but while the subject of a habitat is a species or a population, the subject of a biotope is a biological community.It...
.
The trumpet worm is often eaten by bottom-feeding fish including juvenile common dab
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
Plaice is the common name of four species of flatfishes.Plaice or PLAICE may also refer to:* USS Plaice , a Balao-class submarine* PLAICE, an open source hardware FLASH programmer, memory emulator, and logic analyzer...
.