Leptometra celtica | |
---|---|
![]() | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Echinodermata |
Class: | Crinoidea |
Order: | Comatulida |
Family: | Antedonidae |
Genus: | Leptometra |
Species: | L. celtica |
Binomial name | |
Leptometra celtica McAndrew & Barrett, 1857 [1] | |
Synonyms [1] | |
|
Leptometra celtica is a marine invertebrate and species of crinoid or feather star of the Leptometra genus in the family Antedonidae. It is found in the Atlantic Ocean around the coasts of north west Europe. The presence of L. celtica and L. phalangium (its counterpart in the Mediterranean) is considered to be a good indication of nearby shelf breaks, general bottom currents, and areas of high gross productivity as they are suspension-feeders, hence their proliferation in productive environments. [2]
Leptometra celtica has ten pinnate arms that are typically 7–10 cm in length with neatly held side branches. The arms may be banded in red and white or plain coloured in brown, white or red. In areas of moderate current, specimens have been observed to spread their arms out into a vertical fan across the current. [3]
The cirri of L. celtica are about 34–40 mm in length and vary in color from green to white. They are arranged in irregular columns dimorphically about the organism's stalk allowing for locomotion and attachment to deep sea structures. [4] Examination of cirri can help distinguish L. celtica from the related L. phalangium as the cirri of L. celtica are shorter in proportion and are not evenly tapered distally. The distal segments of the cirri have their distal edge slightly swollen so that the organism's dorsal profile retains a slightly scalloped appearance in comparison to L. phalangium. [5]
L. celtica has short proximal oral pinnule segments protruding from its stalk to allow for feeding. Its oral pinnules are arranged in irregular columns are somewhat shorter in length in comparison to L. phalangium. The four lowest pinnules average between 12–17 mm. [5]
The opening of the centrodorsal cavity in L. celtica is only 0.35 of the centrodorsal diameter, making it similar to that of other species of antedonids. [4]
L. celtica can be found in the Atlantic Ocean ranging from the coasts of the United Kingdom and Faroe Islands to the Moroccan coast. The species has been found at depths between 20 and 1247 m in the western Mediterranean and has been studied in the Algarve region on the southwest coast of Portugal. [2] L. celtica has also been studied along shelf breaks ranging from northwest Spain to the southwest coasts of Ireland. [6] The species can be typically found in sandy to muddy sand types of sediment. [7]
Leptometra celtica are suspension feeders that take in organic particles that fall from the photic zone. [6] Shelf-break upwelling and water turbulence increases the transportation of organic matter up the water column, leading to high-concentrations of crinoids like L. celtica that feed on organic matter around these shelf breaks. The species plays an important role in marine environments by taking in large amounts of organic particles and regulating food chain production. For this reason, the presence of benthopelagic fish alongside crinoids like L. celtica can serve as indicators of highly productive regions of shelf-breaks. [6]
Several studies have focused on the impact of bottom trawling and dredging on crinoid communities along the coast. L. celtica has been found in crinoid beds with a high abundance of juvenile commercial fish and crustacea, and research has shown that heavily towed benthic environments have much lower numbers of crinoid taxa like L. celtica. [7]
Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their juvenile form are commonly called sea lilies, while the unstalked forms, called feather stars or comatulids, are members of the largest crinoid order, Comatulida. Crinoids are echinoderms in the phylum Echinodermata, which also includes the starfish, brittle stars, sea urchins and sea cucumbers. They live in both shallow water and in depths as great as 9,000 meters (30,000 ft).
Comasteridae is a family of crinoids.
Antedon bifida is a species of crinoid in the family Antedonidae commonly known as the rosy feather star. It is found in north west Europe.
Comatulida is an order of crinoids. Members of this order are known as feather stars and mostly do not have a stalk as adults. The oral surface with the mouth is facing upwards and is surrounded by five, often divided rays with feathery pinnules. Comatulids live on the seabed and on reefs in tropical and temperate waters.
Davidaster rubiginosus or the orange sea lily is a species of crinoid in the family Comatulidae. At one time it was classified as Nemaster rubiginosa but the World Register of Marine Species has determined that the valid name is Davidaster rubiginosus. It is found on reefs in the tropical western Atlantic and the Caribbean Sea.
Comaster schlegelii, the variable bushy feather star, is a crinoid in the family Comatulidae. It was previously classified as Comanthina schlegeli but further research showed that it was better placed in the genus Comaster. It is found on shallow water reefs in the western Pacific Ocean.
Metacrinus rotundus, the Japanese sea lily, is a marine invertebrate, a species of stalked crinoid in the family Isselicrinidae. It is a species found off the west coast of Japan, and is living near the edge of the continental shelf, around 100–150m deep. This is the shallowest species among the extant stalked crinoids.
Oxycomanthus bennetti, the Bennett's feather star, is a species of crinoid belonging to the family Comatulidae. It is found in shallow water in the Indo-Pacific between northern Australia and southeast Asia.
Antedon mediterranea is a species of stalkless crinoid in the family Antedonidae, commonly known as the Mediterranean feather star. It is found on the seabed at moderate depths in the Mediterranean Sea. It is a filter feeder and captures plankton with its long feathery arms.
Bourgueticrinida is an order of crinoids that typically live deep in the ocean. Members of this order are attached to the seabed by a slender stalk and are known as sea lilies. While other groups of crinoids flourished during the Permian, bourgueticrinids along with other extant orders did not appear until the Triassic, following a mass extinction event in which nearly all crinoids died out.
Cenocrinus is a monotypic genus of stalked crinoids in the family Isselicrinidae. The great West Indian sea lily is the only species in the genus and is found in deep waters in the Caribbean Sea and Gulf of Mexico.
Ptilometra australis, the passion flower feather star, is a species of crinoid. It is native to the coasts of southeastern Australia where it is found on reefs, in estuaries and bays at depths down to about 110 metres (360 ft).
Leptometra is a genus of free-swimming, stemless crinoids.
Endoxocrinus parrae is a species of stalked crinoids of the family Isselicrinidae. It is the most commonly found isocrinine species in west Atlantic Ocean.
Promachocrinus kerguelensis is a species of free-swimming, stemless crinoids. It was the only member of its genus until several species were discovered in 2023. P. keruguelensis a coldwater crinoid which is found in the seas around Antarctica and surrounding island groups, including under the sea ice.
Aporometra wilsoni is a marine invertebrate, a species of crinoid or feather star in the family Aporometridae. It is found in shallow water around the coasts of southern Australia.
Notocrinus virilis is a marine invertebrate, a species of crinoid or feather star in the family Notocrinidae. It is found in deep water in the Southern Ocean around the coasts of Antarctica and adjacent islands. A sea snail sometimes parasitizes it.
Aporometra paedophora is a marine invertebrate, a species of crinoid or feather star in the family Aporometridae. It was first found at a depth of 22 fathoms off the Manning River on the New South Wales coast. Other specimens were found off the coast of Bunbury, Western Australia at depths between 9 and 15 m. Based on morphological evidence of four specimens of A. paedophora, Helgen & Rouse believe that this may not be a separate species from Aporometra wilsoni.
Cenometra bella is a species of crinoids belonging to the genus Cenometra. They can have up to 30 arms and can be of variable colours but are often characterised by a marked contrast between the extending free-arms and the feathery pinnules. This species clings to its support and moves around by its feet-like cirri.
Flexibilia is a superorder of specialized Paleozoic crinoids. They exhibited a conserved body plan and consistent suite of characteristics throughout their long history. Previously considered a subclass with unclear affinities, later investigation determined that flexibles are well-nested within Cladida, a broad group ancestral to living articulate crinoids. The Ordovician cladid Cupulocrinus acts as an intermediate form linking the generalized anatomy of other early cladids with the distinctive anatomy of flexibles, and several studies have considered it to be ancestral to the rest of the group. Although flexibles never reached the same abundance or diversity as many other crinoid groups, they remained a reliable component of crinoid faunas, particularly from the Silurian onwards. Flexible fossils are very rare in the Ordovician, but the Late Ordovician appears to have been an interval of rapid diversification for the group.
{{cite journal}}
: CS1 maint: multiple names: authors list (link)