Holothuriida

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Holothuriida
Holothuria hilla.jpg
Holothuria hilla
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Echinodermata
Class: Holothuroidea
Order: Holothuriida
Miller, Kerr, Paulay, Reich, Wilson, Carvajal & Rouse, 2017
Families

Holothuriida is an order of sea cucumbers. [1] Taxa within the order Holothuriida were previously classified in the order Aspidochirotida, which was determined to be polyphyletic in 2017. Some taxa were also reclassified into the clades Synallactida and Persiculida. [2]

Contents

Description and characteristics

Species of the order Holothuriida are distinguished from other sea cucumbers by the presence of flattened, often leaf-like tentacles, but without the other large appendages found in the related order Elasipodida. They do not have introvert or retractor muscles. [3] The tube feet often form a clearly demarcated sole. They have 15-30 shield-shaped retractile tentacles surrounding their mouths. The body wall is thick and leathery and contains ossicles, including some table-shaped ones. They have respiratory trees for gas exchange. The mesentery of the posterior loop of their gut is attached to the right ventral interradius. The muscles that run longitudinally down the body are arranged into five double bands. They can emit sticky white threads known as cuvierian tubules from their cloacas in order to distract or entangle predators. They are usually found in exposed shallow-water environments. [4]

Conservation status

Their popularity as luxury seafood in some Asian countries poses a serious threat to the order. [5]

List of families

Related Research Articles

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

Sea cucumbers are echinoderms from the class Holothuroidea. They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. They are found on the sea floor worldwide. The number of known holothurian species worldwide is about 1,786, with the greatest number being in the Asia-Pacific region. Many of these are gathered for human consumption and some species are cultivated in aquaculture systems. The harvested product is variously referred to as trepang, namako, bêche-de-mer, or balate. Sea cucumbers serve a useful role in the marine ecosystem as they help recycle nutrients, breaking down detritus and other organic matter, after which bacteria can continue the decomposition process.

<span class="mw-page-title-main">Stichopodidae</span> Family of sea cucumbers

The Stichopodidae are a family of sea cucumbers, part of the order Synallactida.

<span class="mw-page-title-main">Holothuriidae</span> Family of sea cucumbers

Holothuriidae is a family of sea cucumbers, a type of echinoderm.

<i>Bohadschia argus</i> Species of sea cucumber

Bohadschia argus, the leopard sea cucumber, leopardfish, or tigerfish, is a species of sea cucumber in the family Holothuriidae. It is native to the tropical Western Indo-Pacific region.

<i>Bohadschia</i> Genus of sea cucumbers

Bohadschia is a genus of sea cucumbers in the family Holothuriidae. They are among the largest, most common, and conspicuous sea cucumbers on coral reefs. They have large, loaf-like bodies that are often strikingly colored.

<i>Colochirus quadrangularis</i> Species of sea cucumber

Colochirus quadrangularis, commonly known as the thorny sea cucumber, is a species of sea cucumber in the family Cucumariidae. It is found in shallow seas in tropical parts of the Indo-Pacific region.

<i>Colochirus robustus</i> Species of echinoderm

Colochirus robustus, commonly known as the robust sea cucumber or the yellow sea cucumber, is a species of sea cucumber in the family Cucumariidae. It is found in shallow seas in tropical parts of the central Indo-Pacific region. C. robustus belongs to the class Holothuroidea, a group of echinoderms called sea cucumbers and known for unusual behavior including evisceration, asexual reproduction, and regeneration. The robust sea cucumber has a soft body and lacks a spine, but it does have an endoskeleton consisting of microscopic spicules, or ossicles, made of calcium carbonate. C. robustus has a respiratory tree that allows it to extract oxygen for respiration, using the anus to pump water. The robust sea cucumber is an important dietary staple for many East and Southeast Asian populations, and has been used for medicinal purposes for hundreds of years. Recent research suggests that peptides from C. robustus enhance the activity of the immune system.

<i>Sclerodactyla briareus</i> Species of sea cucumber

Sclerodactyla briareus, commonly known as the hairy sea cucumber, is a species of marine invertebrate in the family Sclerodactylidae. It is found in shallow waters in the western Atlantic Ocean.

<i>Pearsonothuria</i> Genus of sea cucumbers

Pearsonothuria is a genus of sea cucumbers in the family Holothuriidae. Pearsonothuria graeffei is the only species in the genus. Graeffe's sea cucumber is found in the tropical Indo-Pacific Ocean and the type locality is Viti Island, Fiji. It is named after Eduard Heinrich Graeffe, Semper's coworker at the Museum Godeffroy.

<i>Psolus phantapus</i> Species of sea cucumber

Psolus phantapus, also known as the brown psolus, is a species of sea cucumber in the family Psolidae.

<i>Synapta maculata</i> Species of sea cucumber

Synapta maculata, the snake sea cucumber, is a species of sea cucumber in the family Synaptidae. It is found in shallow waters in the tropical Indo-Pacific Ocean. Sometimes growing as long as 3 m (10 ft), it is one of the longest sea cucumbers in the world.

<span class="mw-page-title-main">Chiridotidae</span> Family of sea cucumbers

Chiridotidae is a family of sea cucumbers found in the order Apodida. Within the family, there are 16 recognized genera all with different ranges of body types and functions. Sea cucumbers play a fundamental role in many marine ecosystems.

<span class="mw-page-title-main">Elpidiidae</span> Family of sea cucumbers

Elpidiidae is a family of deep-sea sea cucumbers.

<span class="mw-page-title-main">Persiculida</span> Clade of sea cucumbers

Persiculida is an order of sea cucumbers. Taxa within the order Persiculida were previously classified in an order called Aspidochirotida, which was determined to be polyphyletic in 2017.

<span class="mw-page-title-main">Synallactida</span> Clade of sea cucumbers

Synallactida is a rankless clade of sea cucumbers, but is referred to as an order. Taxa within Synallactida were previously classified in an order called Aspidochirotida, which was determined to be polyphyletic in 2017.

<i>Synaptula recta</i> Species of sea cucumber

Synaptula recta, sometimes known as the gut-like sea cucumber, is a species of sea cucumber in the family Synaptidae in the phylum Echinodermata. It occurs in shallow water in the tropical Indo-Pacific region.

<i>Pawsonia saxicola</i> Species of sea cucumber

Pawsonia saxicola, the sea gherkin, is a species of sea cucumber in the family Cucumariidae. It is found in the northeastern Atlantic Ocean and the Mediterranean Sea.

<i>Paraleptopentacta elongata</i> Species of sea cucumber

Paraleptopentacta elongata is a species of sea cucumber in the family Cucumariidae. It is found in the northeastern Atlantic Ocean and parts of the Mediterranean Sea. It is an infaunal species, occupying a burrow in the seabed, from which its anterior and posterior ends project.

<i>Thyone roscovita</i> Species of echinoderm (sea cucumber)

Thyone roscovita is a species of sea cucumber in the family Phyllophoridae. It is found on gravel, sand and mud substrates in the north-eastern Atlantic Ocean and the Mediterranean Sea at depths down to about 40 m (130 ft). It is a suspension feeder and catches food particles floating past with its branched feeding tentacles.

<i>Holothuria impatiens</i> Species of sea cucumber

Holothuria (Thymiosycia) impatiens, commonly known as the impatient sea cucumber or bottleneck sea cucumber, is a species of sea cucumber in the genus Holothuria, subgenus Thymiosycia.

References

  1. Paulay, Gustav (2017). "Holothuriida". WoRMS. World Register of Marine Species . Retrieved 2017-11-29.
  2. Paulay, Gustav (2017). "Aspidochirotida". WoRMS. World Register of Marine Species . Retrieved 2017-11-29.
  3. An illustrated key to the sea cucumbers of the South Atlantic Bight Retrieved 2012-02-12.
  4. Order Aspidochirotida Marine Species Identification Portal. Retrieved 2012-02-10.
  5. Steven W. Purcell; Beth A. Polidoro; Jean-François Hamel; Ruth U. Gamboa; Annie Mercier (5 March 2014). "The cost of being valuable: predictors of extinction risk in marine invertebrates exploited as luxury seafood". Proceedings of the Royal Society B: Biological Sciences. 281 (1781): 20133296. doi:10.1098/rspb.2013.3296. PMC   3953849 . PMID   24598425.