Red-striped sea cucumber (Thelenota rubralineata)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Echinodermata · Class: Holothuroidea · Order: Synallactida · Family: Stichopodidae · Genus: Thelenota.

Accepted name: Thelenota rubralineata · Authority: Massin & Lane, 1991 · Taxonomic status: accepted · AphiaID: 242080.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=242080 (CC BY 4.0). Accessed 2026-09-25.

Biology and life history (SeaLifeBase)

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

Maximum length: 50 cm · Depth range: 10–35 m · Habitat zone: reef-associated · Vulnerability index: 40 of 100.

SeaLifeBase notes: Inhabitant of the outer reef slope from a depth of 20 m and deeper (Ref. 800).

Source: SeaLifeBase species summary (SpecCode 85178) — https://www.sealifebase.se/summary/Thelenota-rubralineata.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-25.

Distribution and occurrence records (GBIF)

108 georeferenced occurrence records for Thelenota rubralineata are published through GBIF from 12 countries or marine areas. The map above plots 43 distinct locations from a sample of 108 records, omitting 11 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: Papua New Guinea (35); Indonesia (29); Solomon Islands (12); Philippines (11); Marshall Islands (7); Cook Islands (5); Australia (2); Malaysia (2); Vanuatu (2); Northern Mariana Islands (1); New Caledonia (1); French Polynesia (1).

Source: GBIF Occurrence Search (taxonKey 4343233) — https://www.gbif.org/occurrence/search?taxon_key=4343233&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=242080 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-25.

Conservation status (IUCN Red List)

The IUCN Red List assesses Thelenota rubralineata Massin & Lane, 1991 as Endangered (code EN). 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 180285) — https://www.iucnredlist.org/species/180285/0; GBIF IUCN Red List category endpoint (taxonKey 4343233) — https://api.gbif.org/v1/species/4343233/iucnRedListCategory. Accessed 2026-09-25.

Description and natural history (Wikipedia)

Thelenota rubralineata has an elongated, roughly trapezoidal body 30 to 39 cm long and 8 cm wide in its uncontracted state. Like other Thelenota, it has well marked differences between its ventral and dorsal surface, with papillae and pedicels covering its dorsal surface, and numerous podia scattered randomly on its ventral surface. The dorsal protrusions are arranged in two rows of 13 to 15 large, conical arms, many of which ending in spiked papillae. The sides of the body are also covered in a continuous row of multipapillate protrusions, with smaller outgrowths distributed randomly over the body.

The body of T. rubralineata is covered in a complex pattern of red lines on top of a white base. Towards the middle of the body, these lines run parallel and intersect, forming maze-like patterns. The conical protrusions are also covered in this pattern, with papillae ending in white peaks. The podia are pale greenish-yellow, while the tentacles, twenty in number, are red.

Distribution and habitat

Thelenota rubralineata is found on outer coral reef slopes with large rubble and coarse sand patches near islands 20 meters and deeper. This species is widespread throughout the Indo-Pacific region.

Biology

Like other Thelenota, T. rubralineata contains calcareous spicules in the form of granules and branched rods. Located throughout the body wall, these structures serve as both structural support and defense from predators.

Two polian vesicles provide the basis for locomotion. Five longitudinal muscles are broad, V-shaped, and attached to the body wall. A short digestive tract, two narrow respiratory trees, and a small circulatory system running parallel to the intestines is also present.

When in motion, the lateral protuberances play a role in walking. When disturbed, T. rubralineata bends its body in a helical fashion, arranging its mouth close to the anus, and assumes this position for up to 10 minutes or longer, then moves again.

Lifespan for this species is currently unknown. However, like other echinoderms, T. rubralineata is suspected to regenerate. As a result, lifespan cannot be estimated, but is assumed to be greater than multiple decades in their natural environment.

Commercial uses

Thelenota rubralineata and other species of echinoderms are commonly harvested in the Western Central Pacific region. Thelenota is often harvested in many regions of Micronesia, Polynesia, Melanesia, Australia, and New Zealand. When observed by divers, T. rubralineata was widespread but rarely found in large densities. Although T. rubralineata is not one of the most economically profitable species for fisheries, this species may become more prone to over-fishing due to a reduction in more commonly used species of echinoderms.

Source: Wikipedia: Thelenota rubralineata — https://en.wikipedia.org/wiki/Thelenota_rubralineata (CC BY-SA 4.0). Accessed 2026-09-25.