Marine Invertebrates Codexery

Sea cucumber

Last updated

Sea cucumber

Diego Delso / Diego Delso · via Wikipedia: Sea cucumber · CC BY-SA 4.0

They are benthic marine animals found on the sea floor worldwide, serving as detritivores that help recycle nutrients by breaking down detritus and organic matter.[1] Holothuroidea is the class to which sea cucumbers, echinoderms with elongated bodies and leathery skin, belong; their name comes from a resemblance to cucumber fruit.[1][2]

Scientific classification

  1. KingdomAnimalia
  2. PhylumEchinodermata
  3. ClassHolothuroidea

Named by Blainville, 1834

Sources: Wikipedia taxobox: Sea cucumber (CC BY-SA 4.0)

Last updated 2026-10-07 from the source article.

Quick Facts

Class
Holothuroidea
Typical length
10 to 30 cm (3.9 to 11.8 in / 30 cm)
Extremes length
3 mm (0.12 in) to over 3 m (9.8 ft)
Ecological role
detritivore

Facts from the source article.

Key facts and history

Most sea cucumbers have a soft, cylindrical body ranging from almost spherical to serpent-like, typically measuring between 10 and 30 cm long.[3] Their mouth is surrounded by retractile tentacles, and they possess a calcified dermal endoskeleton usually reduced to microscopic ossicles.[2][3] The body wall contains "catch" collagen that can be loosened or tightened at will, allowing the animal to squeeze through small gaps.[4] They use cloacal respiration via a pair of "respiratory trees" that branch inside the cloaca just inside the anus.[5]

A neural tissue ring encircles the oral cavity of sea cucumbers, which lack a true brain, and this ring extends nerves to both the pharynx and the tentacles.[6] Sperm and ova are released into ocean water by most sea cucumbers for reproduction, and the species are typically dioecious, meaning males and females are separate.[6] The auricularia, a larval stage measuring about 1 mm, is the first developmental phase; it uses a lengthy cilia band for swimming.[6] Evisceration, a defensive process, involves some sea cucumber species expelling sticky cuvierian tubules through a cloaca wall tear.[7]

What the cited sources add

The Echinoblog notes that swimming sea cucumbers have not been observed to eviscerate like shallow ones do, and their bodies are often very gelatinous and neutrally buoyant.[8] It also states that a large proportion of sea cucumbers are capable of swimming, and they can maneuver themselves out of the way of underwater mudslides.[8] The same source adds that these sea cucumbers prefer fresh organic matter that has just fallen onto the sea floor.[8]

References

  1. Wikipedia, "Sea cucumber" (CC BY-SA 4.0), which cites: Paulay, "Holothuroidea", World Register of Marine Species, 2014; "Transcriptome Sequencing and Characterization for the Sea Cucumber Apostichopus japonicus (Selenka, 1867)", PLOS One, 2012; "Transcriptome Sequencing and Characterization for the Sea Cucumber Apostichopus japonicus (Selenka, 1867)", PLOS One, 2012 (we also read that source) en.wikipedia.org
  2. Wikipedia, "Sea cucumber" (CC BY-SA 4.0), which cites: Reich, "Cambrian holothurians? – The early fossil record and evolution of Holothuroidea", Journées Georges Ubaghs, 30–31 January 2006, p. 36–37 (original not read by us) en.wikipedia.org
  3. Wikipedia, "Sea cucumber" (CC BY-SA 4.0), which cites: Walters, "Encyclopedia of Animals", Marks and Spencer p.l.c, 2003, p. 68 (original not read by us) en.wikipedia.org
  4. Wikipedia, "Sea cucumber" (CC BY-SA 4.0), which cites: "Catch" collagen has two states, soft and stiff, that are under neurological control.Jose del Castillo and David S. Smith. (1996) "We Still Invoke Friction and (original not read by us) en.wikipedia.org
  5. Wikipedia, "Sea cucumber" (CC BY-SA 4.0), which cites: "Holothurians or sea cucumbers"; Ingram, "Knowing Nature... Cool as a Sea Cucumber", 2006-06-16 (original not read by us) en.wikipedia.org
  6. Wikipedia, "Sea cucumber" (CC BY-SA 4.0), which cites: Barnes, Robert D., "Invertebrate Zoology", Holt-Saunders International, 1982, p. 981–997 (we also read that source) en.wikipedia.org
  7. Wikipedia, "Sea cucumber" (CC BY-SA 4.0), which cites: "Transcriptome Sequencing and Characterization for the Sea Cucumber Apostichopus japonicus (Selenka, 1867)", PLOS One, 2012; Flammang, "Biomechanics of adhesion in sea cucumber Cuvierian tubules (Echinodermata, Holothuroidea)", Integrative and Comparative Biology, 2002-12-01, p. 1107–1115 (we also read that source) en.wikipedia.org
  8. Mah, "Deep-Sea Swimming Sea Cucumbers and the "most bizarre holothurian species in existence" !", The Echinoblog, 2012-09-18. facts only, no text reused. echinoblog.blogspot.com

Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Sea cucumber (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.

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Sources

Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.

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