Pearsonothuria
A monotypic sea cucumber genus with toxic tubules and mimicry.
Last updated
Pearsonothuria is a genus of sea cucumbers in the family Holothuriidae. It contains a single species, Pearsonothuria graeffei, commonly known as Graeffe's sea cucumber. This species is notable for its striking juvenile coloration that mimics a toxic sea slug, and for the bioactive compounds in its cuvierian tubules that are being studied for potential medical applications.
Scientific classification
- KingdomAnimalia
- PhylumEchinodermata
- ClassHolothuroidea
- OrderHolothuriida
- FamilyHolothuriidae
- GenusPearsonothuria
- SpeciesPearsonothuria graeffei
Named by Semper, 1868
Sources: Wikipedia taxobox: Pearsonothuria (CC BY-SA 4.0) · order, family and genus agree with WoRMS AphiaID 210772 (CC BY 4.0)
Conservation status
Least Concern (LC)
- LC▲ this species
- NT
- VU
- EN
- CR
- EW
- EX
Source: IUCN Red List assessment · GBIF copy of the Red List category
Where the pearsonothuria has been recorded
Each dot is a place where the species has been observed and reported (2,895 records, half-degree grid) — not a modelled range. 30 inland records left out (institution coordinates). 6 isolated far-off records not drawn.
Map: drawn by Codexery. Data: GBIF occurrence search (records CC0 / CC BY) · Natural Earth basemap (public domain)
Quick Facts
- Species
- graeffei
Facts from the source article.
Background
Pearsonothuria graeffei is a roughly cylindrical, thin-walled sea cucumber that grows to about 30 centimetres in length. Its mouth is surrounded by up to 24 leaf-like, paddle-shaped tentacles with black stalks that are black on the upper side and white beneath. The anus is at the opposite end, and several rows of tube feet run along the underside. Adults are pale brown and white with black speckles and small thornlike protuberances.
Juveniles are brightly colored white and blue or black, with a few large, yellow, thornlike projections, closely resembling the sea slug Phyllidia varicosa, whose bright colors warn predators of its toxicity. The juvenile appearance changes when they grow larger than the slug and the mimicry is no longer effective. The species is named after Eduard Heinrich Graeffe, Semper's coworker at the Museum Godeffroy, and the type locality is Viti Island, Fiji.
More in Sea Cucumbers
Elsewhere in Sea Cucumbers and Brittle Stars
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.
- Wikipedia: Pearsonothuria (CC BY-SA 4.0).
- Classification: the source article's taxobox; order, family and genus checked against WoRMS, the World Register of Marine Species (CC BY 4.0).
- Conservation status: IUCN Red List assessment.
- Occurrence records: GBIF (CC0 / CC BY). Basemap: Natural Earth (public domain).
- Word definitions: the Codexery glossary, each quoted from its Wikipedia article.
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