Lollyfish (Holothuria atra)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Echinodermata · Class: Holothuroidea · Order: Holothuriida · Family: Holothuriidae · Genus: Holothuria.

Accepted name: Holothuria atra · Authority: Jaeger, 1833 · Taxonomic status: accepted · AphiaID: 1672768.

Synonyms and superseded combinations recorded for this taxon: Halodeima atra (Jaeger, 1933); Holothuria (Halodeima) atra Jaeger, 1833; Holothuria (Halodeima) atra amboinensis Théel, 1886; Holothuria (Holothuria) atra Jaeger, 1833; Holothuria (Microthele) affinis Brandt, 1835; Holothuria amboinensis Semper, 1868; Holothuria radackensis Chamisso & Eysenhardt, 1821; Holothuria sanguinolenta Saville-Kent, 1893.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=1672768 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (SeaLifeBase)

Measured values published by SeaLifeBase for Holothuria atra. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 60 cm · Common length: 20 cm · Depth range: 0–30 m · Habitat zone: benthic · Vulnerability index: 31.8 of 100 · Fishery importance: minor commercial.

SeaLifeBase notes: The mean population density is around 0.5 per square meter, but can exceed 4 per square meter. Traditionally harvested, but the processed product is of low commercial value. In recent times, due to increasing demand, this species also appears in the processed products of many Pacific Islands. Collected by hand at low tide while wading on the reefs, or by divers (Ref. 122). Processed to trepang in Puerto Princesa, Palawan (Ref. 543). A common shallow-water species, rarely found at depths of more than 20 m, mostly on inner and outer reef flats and back reefs or shallow coastal lagoons; abundant on sandy-muddy grounds with rubble or coral patches and in seagrass beds (Ref. 122). Intertidal. Also found on coarse and fine sandy areas in coral communities (Ref. 129602). Body is often almost completely covered by sand grains (Ref. 102838). The mean population density is about 0.5/square meter, but can exceed 4/square meter. Inshore shallow-water populations are denser, composed of smaller individuals, while deeper or outer reef populations, individuals are more scattered and with larger sizes (Ref. 122). Feeds on Halimeda sp. (Ref. 118). Known to release a wine-colored exudate when rubbed vigorously (Ref. 85218).

Source: SeaLifeBase species summary (SpecCode 50229) — https://www.sealifebase.se/summary/Holothuria-atra.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

10,834 georeferenced occurrence records for Holothuria atra are published through GBIF from 80 countries or marine areas. The map above plots 366 distinct locations from a sample of 3,000 records, omitting 49 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: New Caledonia (1,213); French Polynesia (1,042); United States of America (856); Australia (766); Wallis and Futuna (751).

The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.

Source: GBIF Occurrence Search (taxonKey 2279167) — https://www.gbif.org/occurrence/search?taxon_key=2279167&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=1672768 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Holothuria atra Jaeger, 1833 as Least Concern (code LC). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 180421) — https://www.iucnredlist.org/species/180421/0; GBIF IUCN Red List category endpoint (taxonKey 2279167) — https://api.gbif.org/v1/species/2279167/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

Holothuria atra is a sea cucumber that can grow to a length of 60 cm but 20 cm is a more common size. It has a smooth, pliable, entirely black skin which often has sand adhering to it, especially in smaller individuals. The mouth is on the underside at one end and is surrounded by a fringe of 20 black, branched tentacles. The anus is at the other end.

Holothuria atra is found in the tropical Indo-Pacific region, its range extending from the Red Sea and East Africa to Australia. It is found on the seabed, in shallow waters on reefs and sand flats and in seagrass meadows at depths of up to 20 m. Its colouring makes it conspicuous but it is very often camouflaged by a coating of sand which may also serve to keep it cool by protecting it from the sun's rays. It favours reef flats where it is not fully exposed to the waves but the water is well aerated, and shallows beside slabs of rock from under which cool water wells out when the tide retreats. In such places it is often found in pools above the low tide mark which are warmed by the sun during the day. Holothuria atra seems to tolerate these high temperatures well and individuals appeared healthy and were feeding when the water temperature rose as high as 39 °C.

Holothuria atra is an omnivore, sifting through the sediment with its tentacles and feeding on detritus and other organic matter. As a defence against predators, Holothuria atra emits a toxic red fluid when its skin is rubbed or damaged. When attacked, it does not eject Cuvierian tubules in the way that some sea cucumbers do, but instead extrudes its internal organs through its anus.

It is not possible to distinguish between male and female Holothuria atra externally. Maturity is reached at a body length of about 16 cm and spawning mostly takes place during the summer and autumn although in equatorial waters it may take place all year round. It takes a minimum of 18-25 days for Holothuria atra to reach natural competence. Holothuria atra is also fissiparous, meaning that it can reproduce by transverse fission. It is mostly smaller individuals which divide in this way. A constriction appears, becomes deeper and deeper, and after some time the integument separates leaving two relatively wide but short individuals. No sand adheres to the newly separated surfaces as there are no tube feet present to retain the grains.

Holothuria atra, like many echinoderms, engage in sediment bioturbation—a process which plays an important role in the health of coral reefs. Holothuria atra is often found associated with the polychaete worm Gastrolepidia clavigera, a black worm which crawls about over the sea cucumber's skin. Holothuria atra seems to have few natural predators.

Lissocarcinus orbicularis, a small crab, is known to live on this species in a commensal relationship.

In the Pacific Islands, Holothuria atra is collected by diving or by wading at low tide, and used for human consumption; its commercial value, however, is low. On Guam, the toxic red fluid that Holothuria atra releases is utilized to drive octopuses out of hiding holes.

Compounds of potential biomedical importance are present in Holothuria atra, including lectin, steroidal sapogenins and triterpene glycoside.

Source: Wikipedia: Holothuria atra — https://en.wikipedia.org/wiki/Holothuria_atra (CC BY-SA 4.0). Accessed 2026-09-23.

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