Pearsonothuria

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Pearsonothuria graeffei
Pearsonothuria graeffei Landaagiraavaru.JPG
Pearsonothuria graeffei in the Maldives
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Echinodermata
Class: Holothuroidea
Order: Holothuriida
Family: Holothuriidae
Genus: Pearsonothuria
Levin, 1984 [2]
Species:
P. graeffei
Binomial name
Pearsonothuria graeffei
Semper, 1868 [3]
Synonyms [3]
  • Bohadschia drachi Cherbonnier, 1954
  • Bohadschia graeffei (Semper, 1868)
  • Holothuria graffei Semper, 1868
  • Stichopus troschelii Müller, 1854

Pearsonothuria is a genus of sea cucumbers in the family Holothuriidae. Pearsonothuria graeffei is the only species in the genus. [2] Graeffe's sea cucumber is found in the tropical Indo-Pacific Ocean and the type locality is Viti Island, Fiji. [3] It is named after Eduard Heinrich Graeffe, Semper's coworker at the Museum Godeffroy.

Contents

Description

Pearsonothuria graeffei is a roughly cylindrical, thin-walled sea cucumber that grows to about 30 centimetres (12 in) in length. [4] Its mouth, at one end, is surrounded by a ring of up to 24 leaf-like, paddle-shaped tentacles with black stalks which are black on the upper side and white beneath. The anus is at the other end of the body and there are several rows of tube feet along the underside. The colour of the adults is pale brown and white, with black speckles and small thornlike protuberances.

By contrast, the juveniles are brightly coloured, being white and blue or black, with a few large, yellow, thornlike projections. This colouration makes them closely resemble the sea slug, Phyllidia varicosa , the bright colours of which warn predators of its toxicity. The appearance of the juvenile sea cucumbers begins to change when they grow larger than the slug and the mimicry is no longer effective. [5]

Distribution

Pearsonothuria graeffei bouche.JPG

Pearsonothuria graeffei is found in tropical parts of the Indo-Pacific Ocean. The range extends from the east coast of Africa to the Philippines, Indonesia and the South Pacific. It is found on the seabed and on coral reefs at depths down to about 25 metres (82 ft). [3] [4]

Biology

Pearsonothuria graeffei is a scavenger and roams around on the seabed sifting through the sediment with its feeding tentacles. Any organic matter it finds is passed to its mouth by the tentacles. [6] Its daily activities start within a few minutes of dawn and continue until half an hour after sunset after which time it adopts an inactive stance with its rear end raised and its tentacles retracted into its mouth. It then remains immobile during the night. [7] They are known to spawn simultaneously with other Echinoderms, including the crown-of-thorns starfish and the sea urchin Diadema setosum. [8]

When threatened or disturbed, many sea cucumbers eject cuvierian tubules, thin white sticky strands of viscera, from their cloacas. Pearsonothuria graeffei seems reluctant to do this except under conditions of extreme stress. The threads of this species contain glycosides that are toxic to the aggressor. The effect of these neuro-toxins is to prevent nerve impulses being transmitted, an effect similar to that produced by cocaine. The chemicals, echinoside A and ds-echinoside A, are being investigated for their possible use by humans as painkillers or anti-tumour drugs. [5] Experiments in vitro show that they have marked anti-cancer activity in Hep G2 cells and that, when given to mice with H22 hepatocellular carcinoma tumours (liver cancer), the weight of the tumours was reduced by about 50%. [9]

Related Research Articles

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

Holothuriida is an order of sea cucumbers. 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.

<i>Phyllidia varicosa</i> Species of mollusc

Phyllidia varicosa is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Phyllidiidae.

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

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

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

Holothuria atra, commonly known as the black sea cucumber or lollyfish, is a species of marine invertebrate in the family Holothuriidae. It was placed in the subgenus Halodeima by Pearson in 1914, making its full scientific name Holothuria (Halodeima) atra. It is the type species of the subgenus.

<i>Stichopus chloronotus</i> Species of sea cucumber

Stichopus chloronotus is a species of sea cucumber. Common names include the greenfish sea cucumber, the spiky sea cucumber and the black knobby sea cucumber. It is native to the Indo-Pacific region. It has a wide range and is abundant and the IUCN lists it as being of "Least Concern".

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

Holothuria scabra, or sandfish, is a species of sea cucumber in the family Holothuriidae. It was placed in the subgenus Metriatyla by Rowe in 1969 and is the type species of the subgenus. Sandfish are harvested and processed into "beche-de-mer" and eaten in China and other Pacific coastal communities.

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

Holothuria tubulosa, the cotton-spinner or tubular sea cucumber, is a species of sea cucumber in the family Holothuriidae. It is the type species of the genus Holothuria and is placed in the subgenus Holothuria, making its full name Holothuria (Holothuria) tubulosa.

<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 marmorata</i> Species of sea cucumber

Bohadschia marmorata, commonly known as the brown sandfish or chalky cucumber, is a species of sea cucumber in the family Holothuriidae. It lives on the seabed in shallow waters in the Indo-Pacific region.

<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.

Holothuria spinifera, the brown sandfish, is a species of sea cucumber in the family Holothuriidae. It is placed in the subgenus Theelothuria, making its full name Holothuria (Theelothuria) spinifera. In India it is known as cheena attai or raja attai. It lives in tropical regions of the west Indo-Pacific Ocean at depths ranging from 32 to 60 metres. It is fished commercially to produce beche-de-mer.

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

Holothuria floridana, the Florida sea cucumber, is a species of marine invertebrate in the family Holothuriidae. It is found on the seabed just below the low tide mark in Florida, the Gulf of Mexico, the Bahamas and the Caribbean.

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

Holothuria edulis, commonly known as the edible sea cucumber or the pink and black sea cucumber, is a species of echinoderm in the family Holothuriidae. It was placed in the subgenus Halodeima by Pearson in 1914, making its full scientific name Holothuria (Halodeima) edulis. It is found in shallow water in the tropical Indo-Pacific Ocean.

<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.

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

Holothuria fuscocinerea, the ashy pink sea cucumber, is a species of sea cucumber in the family Holothuriidae. It is placed in the subgenus Stauropora, making its full name Holothuria (Stauropora) fuscocinerea. It is native to shallow water in the tropical and sub-tropical Indo-Pacific.

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

Holothuria fuscopunctata, the elephant trunkfish, is a species of sea cucumber in the family Holothuriidae native to shallow water in the tropical Indo-Pacific. It is placed in the subgenus Microthele, making its full name Holothuria (Microthele) fuscopunctata.

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

Holothuria hilla is a species of sea cucumber in the subgenus Mertensiothuria of the genus Holothuria. Some common names include the contractile sea cucumber, the sand sifting sea cucumber and the tigertail sea cucumber, and in Hawaii it is known as the light spotted sea cucumber. It is found in the Indo-Pacific region and the Red Sea.

<i>Actinopyga varians</i> Species of sea cucumber

Actinopyga varians, the Pacific white-spotted sea cucumber or Hawaiian sea cucumber, is a species of sea cucumber in the family Holothuriidae. It is found in the Pacific Ocean near Hawaii and also in the Indo-Pacific Ocean.

References

  1. ↑ Conand, C.; Gamboa, R.; Purcell, S. (2013). "Pearsonothuria graeffei". IUCN Red List of Threatened Species . 2013: e.T180248A1605468. doi: 10.2305/IUCN.UK.2013-1.RLTS.T180248A1605468.en . Retrieved 19 November 2021.
  2. 1 2 Martinez, Olga (2006). "Pearsonothuria Levin in Levin, Kalinin & Stonik, 1984". WoRMS. World Register of Marine Species . Retrieved 2012-02-16.
  3. 1 2 3 4 Paulay, Gustav (2010). "Pearsonothuria graeffei (Semper, 1868)". WoRMS. World Register of Marine Species . Retrieved 2012-02-16.
  4. 1 2 "Graeffe's sea cucumber]". Tropical Reefs. Retrieved 2012-02-16.
  5. 1 2 "Invertebrate of the month: Pearsonothuria graeffei". Florida Museum of Natural History. Retrieved 2012-02-16.
  6. ↑ "Pearsonothuria graeffei". Wildwatch.com. Retrieved 2012-02-16.
  7. ↑ Behavioral Effects of Light on the Tropical Holothurian Pearsonothuria graeffei Society for Integrative and Behavioral Biology. Retrieved 2012-02-16.
  8. ↑ Scott, C. M.; Mehrotra, R.; Urgell, P. (2014-08-23). "Spawning observation of Acanthaster planci in the Gulf of Thailand". Marine Biodiversity. 45 (4): 621–622. doi:10.1007/s12526-014-0300-x.
  9. ↑ Zhao, Qin; et al. (2011). "In vitro and in vivo anti-tumour activities of echinoside A and ds-echinoside A from Pearsonothuria graeffei". Journal of the Science of Food and Agriculture. 92 (4): 965–974. doi:10.1002/jsfa.4678. PMID   22012678.
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