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

Description
[edit]
Pearsonothuria graeffei is a roughly cylindrical, thin-walled sea cucumber that grows to about 30 centimetres (12 in) in size. [4] Its mouth, at one finish, is surrounded by a ring of up to 24 leaf-like, paddle-shaped tentacles with black stalks that are black on the higher facet and white beneath. There are a number of rows of tube ft alongside the underside. The anus is at the other finish of the physique. The color of the adults is pale brown and white, with black speckles and small thornlike protuberances.

By distinction, the juveniles are brightly coloured, being white and blue or black, with a number of giant, yellow, thornlike projections. The looks of the juvenile sea cucumbers begins to vary once they develop larger than the slug and the mimicry is no longer efficient. This colouration makes them closely resemble the sea slug, Phyllidia varicosa, the shiny colours of which warn predators of its toxicity. [5]

A stay juvenile particular person of Pearsonothuria graeffei, in situ off Madagascar

Adult specimen in the Maldives

Shut-up on the tentacles

Sperm launch during a mass spawning occasion on the island of Koh Tao, Thailand

Distribution
[edit]
Pearsonothuria graeffei is found in tropical components of the Indo-Pacific Ocean. [2][4] The range extends from the east coast of Africa to the Philippines, Indonesia and the South Pacific. It is discovered on the seabed and on coral reefs at depths down to about 25 metres (eighty two ft).

Biology
[edit]
Pearsonothuria graeffei is a scavenger and roams around on the seabed sifting through the sediment with its feeding tentacles. Any natural matter it finds is handed to its mouth by the tentacles. [8] [7] They are known to spawn concurrently with different Echinoderms, including the crown-of-thorns starfish and the sea urchin Diadema setosum. It then stays immobile throughout the evening. [6] Its every day activities start inside a few minutes of daybreak and continue till half an hour after sunset after which time it adopts an inactive stance with its rear finish raised and its tentacles retracted into its mouth.

When threatened or disturbed, many sea cucumbers eject cuvierian tubules, skinny white sticky strands of viscera, from their cloacas. The impact of these neuro-toxins is to stop nerve impulses being transmitted, an impact just like that produced by cocaine. The chemicals, echinoside A and ds-echinoside A, are being investigated for their doable use by people as painkillers or anti-tumour medication. Pearsonothuria graeffei appears reluctant to do this except under situations of excessive stress. [5] Experiments in vitro present that they have marked anti-most cancers exercise in Hep G2 cells and that, when given to mice with H22 hepatocellular carcinoma tumours (liver most cancers), the load of the tumours was reduced by about 50%.[9] The threads of this species comprise glycosides which are toxic to the aggressor.

^ 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.

^ a b c d Paulay, Gustav (2010). “Pearsonothuria graeffei (Semper, 1868)”. WoRMS. World Register of Marine Species. Retrieved 2012-02-16.

^ a b Martinez, Olga (2006). “Pearsonothuria Levin in Levin, Kalinin & Stonik, 1984”. WoRMS. World Register of Marine Species. Retrieved 2012-02-16.

^ a b “Graeffe’s sea cucumber]”. Tropical Reefs. Retrieved 2012-02-16.

^ a b “Invertebrate of the month: Pearsonothuria graeffei”. Florida Museum of Natural History. Retrieved 2012-02-16.

^ “Pearsonothuria graeffei”. Wildwatch.com. Retrieved 2012-02-16.

^ Behavioral Results of Mild on the Tropical Holothurian Pearsonothuria graeffei Society for Integrative and Behavioral Biology. Retrieved 2012-02-16.

^ Scott, C. M.; Mehrotra, R.; Urgell, P. (2014-08-23). “Spawning remark of Acanthaster planci within the Gulf of Thailand”. Marine Biodiversity. 45 (4): 621-622. doi:10.1007/s12526-014-0300-x.

^ Zhao, Qin; et al. (2011). “In vitro and in vivo anti-tumour actions of echinoside A and ds-echinoside A from Pearsonothuria graeffei”. Ninety two (4): 965-974. doi:10.1002/jsfa.4678. PMID 22012678. Journal of the Science of Food and Agriculture.

Images of Pearsonothuria within the Sealife Assortment

Holothuriidae

Genera

Actinopyga

Bohadschia

Holothuria

Labidodemas

Class

WikiProject

Wikidata: Q18585248

Wikispecies: Pearsonothuria

AFD: Pearsonothuria

Daring: 197360

CoL: 7PQKJ

EoL: 2984444

GBIF: 4343079

iNaturalist: 347257

IRMNG: 1003529

ITIS: 1077909

NCBI: 240140

Open Tree of Life: 18331

WoRMS: 204297

Pearsonothuria graeffei

Wikidata: Q910552

AFD: Pearsonothuria_graeffei

Daring: 197361

CoL: 75W69

EoL: 2984445

GBIF: 4343080

iNaturalist: 347256

IRMNG: 10528523

ITIS: 1079311

IUCN: 180248

NCBI: 240141

OBIS: 210772

Open Tree of Life: 18329

SeaLifeBase: 83493

TaiCOL: t0031671

WoRMS: 210772

Retrieved from “https://en.wikipedia.org/w/index.php?title=Pearsonothuria&oldid=1354662677”

IUCN Crimson Checklist least concern species

Sea cucumber genera

Monotypic echinoderm genera

Dendrochirotida

Echinoderms of the Indian Ocean

Echinoderms of the Pacific Ocean

Taxa named by Carl Semper

Taxa described in 1868

Taxonbars with a number of guide Wikidata items

This web page was last edited on 17 Might 2026, at 17:33 (UTC).

Pearsonothuria