Promachocrinus kerguelensis

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Promachocrinus kerguelensis
Promachocrinus kerguelensis (YPM IZ 049820).jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Echinodermata
Class: Crinoidea
Order: Comatulida
Family: Antedonidae
Genus: Promachocrinus
Species:
P. kerguelensis
Binomial name
Promachocrinus kerguelensis
Carpenter, 1879 [1]
Synonyms [1]
  • Promachocrinus joubini Vaney, 1910
  • Promachocrinus vanhoffenianus Minckert, 1905

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. [2] P. keruguelensis a coldwater crinoid which is found in the seas around Antarctica and surrounding island groups, including under the sea ice. [3]

Contents

Description

This crinoid is one of two living genera that has ten radial ossicles, each giving rise to a pair of arms; there is a single canal in each radial ossicle and no basal rays. [4] At the base are a number of clawed structures known as cirri. [5]

Distribution and habitat

P. kerguelensis is endemic to the waters of Antarctica. Its range includes the Graham Land peninsula, the South Shetland Islands, South Georgia and the South Sandwich Islands, Bouvet Island, Heard Islands and the Kerguelen Islands. The type locality is at the Kerguelen Islands, and it is from here that it gets its specific name. It occurs at depths between about 20 and 1,080 m (100 and 3,500 ft). [1] This is a common and abundant species in the waters around Antarctica, but molecular studies have suggested that it may not be a single species. As many as five or six different "phylogroups" have been identified, each having a circumpolar distribution, being sympatric (living alongside each other) and being adapted to a wide range of depths. [4] [6] The large depth range of this species may be because its non-feeding larvae have a yolk which makes them buoyant, giving them a wide dispersal potential but a limited ability to select where to settle. [6]

Ecology

These crinoids inhabit either rocky areas or soft sediments and can move about using their cirri to grip the substrate, or swim by flapping their arms. They are suspension feeders, choosing locations with strong currents and extending their arms, catching plankton and suspended particles floating past with the tube feet on the pinnules. The tube feet are covered with sticky mucus that traps the food particles, which are then rolled into balls and moved along the ambulacral groove in the arms by cilia which propel them to the mouth. [5]

They are parasitized by the myzostomid polychaete Myzostoma divisor . [7]

Related Research Articles

<span class="mw-page-title-main">Echinoderm</span> Exclusively marine phylum of animals with generally 5-point radial symmetry

An echinoderm is any member of the phylum Echinodermata. The adults are recognisable by their radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or "stone lilies". Adult echinoderms are found on the sea bed at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7,000 living species, making it the second-largest grouping of deuterostomes, after the chordates. Echinoderms are the largest entirely marine phylum. The first definitive echinoderms appeared near the start of the Cambrian.

<span class="mw-page-title-main">Crinoid</span> Class of echinoderms

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).

<i>Antedon bifida</i> Species of crinoid

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.

<i>Antedon petasus</i> Species of crinoid

Antedon petasus is a marine invertebrate, a species of crinoid or feather star in the family Antedonidae. It is found around the coasts of north west Europe.

<span class="mw-page-title-main">Comatulida</span> Order of crinoids

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 discoideus, the beaded crinoid, is a species of feather star in the family Comatulidae. It was previously known as Nemaster discoidea but the World Register of Marine Species has determined that the valid name is Davidaster discoideus. It is found on reefs in the Caribbean Sea and northern coast of South America.

<i>Comaster schlegelii</i> Species of crinoid

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.

<i>Metacrinus rotundus</i> Species of crinoid

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.

<span class="mw-page-title-main">Bourgueticrinida</span> Extinct order of crinoids

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.

<i>Cenocrinus</i> Genus of crinoids

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.

<i>Ptilometra australis</i> Species of crinoid

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).

<i>Florometra serratissima</i> Species of crinoid

Florometra serratissima is a species of crinoid or feather star in the family Antedonidae. It is found off the Pacific coast of North America, usually in deep water.

<i>Endoxocrinus parrae</i> Species of crinoid

Endoxocrinus parrae is a species of stalked crinoids of the family Isselicrinidae. It is the most commonly found isocrinine species in west Atlantic Ocean.

<i>Aporometra wilsoni</i> Species of crinoid

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.

<i>Notocrinus virilis</i> Species of crinoid

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.

<i>Aporometra paedophora</i> Species of crinoid

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.

<i>Promachocrinus</i> Genus of crinoids

Promachocrinus is a genus of free-swimming, stemless crinoids. It was a monotypic genus, with the only species in the genus being Promachocrinus kerguelensis, until the discovery of four new species, establishment of two others previously described and the transfer of another species to the genus in 2023. Known for being coldwater crinoids, members of Promachocrinus are typically found in the seas around Antarctica and surrounding island groups, including under the sea ice. Previously known for having 20 arms, two of the species now included in the genus have 10 arms. Many of the species are circum-Antarctic and can be difficult to tell apart without DNA sequencing.

Promachocrinus fragarius, commonly known as the Antarctic strawberry feather star, is a species of stemless, free-swimming crinoid. It was one of several new species of Promachocrinus to be described in 2023. The discovery of the species gained significant media attention.

<i>Myzostoma divisor</i> Species of marine polychaete

Myzostoma divisor is a species of parasitic marine polychaete in the order Myzostomida.

<i>Myzostoma josefinae</i> Species of marine polychaete

Myzostoma josefinae is a species of parasitic marine polychaete in the order Myzostomida.

References

  1. 1 2 3 Messing, Charles (2012). "Promachocrinus kerguelensis Carpenter, 1879". WoRMS. World Register of Marine Species . Retrieved 11 March 2019.
  2. ↑ McLaughlin, Emily L.; Wilson, Nerida G.; Rouse, Greg W. (2023-07-14). Riesgo, Ana (ed.). "Resolving the taxonomy of the Antarctic feather star species complex Promachocrinus 'kerguelensis' (Echinodermata: Crinoidea)". Invertebrate Systematics. 37 (7): 498–527. doi:10.1071/IS22057. ISSN   1445-5226.
  3. ↑ Ballesta, Laurent (1 July 2017). "Deepest Dive Ever Under Antarctica Reveals a Shockingly Vibrant World". National Geographic Society. Retrieved 11 March 2019.
  4. 1 2 O'Hara, Timothy; Byrne, Maria (2017). Australian Echinoderms: Biology, Ecology and Evolution. Csiro Publishing. p. 215. ISBN   978-1-4863-0763-0.
  5. 1 2 Ruppert, Edward E.; Fox, Richard, S.; Barnes, Robert D. (2004). Invertebrate Zoology, 7th edition. Cengage Learning. pp. 919–920. ISBN   978-81-315-0104-7.{{cite book}}: CS1 maint: multiple names: authors list (link)
  6. 1 2 Verde, Cinzia; di Prisco, Guido (2012). Adaptation and Evolution in Marine Environments, Volume 2: The Impacts of Global Change on Biodiversity. Springer Science & Business Media. p. 47. ISBN   978-3-642-27349-0.
  7. ↑ Summers, Mindi M.; Al-Hakim, Iin Inayat; Rouse, Greg W. (2014). "Myzostoma josefinae In Turbo-taxonomy: 21 new species of Myzostomida (Annelida)". Zootaxa. 3873 (4): 313–314. doi:10.5281/zenodo.6138517.
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