Species · GBIF taxon 2279167
Black Sea Cucumber
Holothuria atraAlso known as Lollyfish
Black sea cucumbers are sausage-shaped marine invertebrates that slowly vacuum the sandy seafloor of tropical reefs. They often coat themselves in a thin layer of sand for sun protection and camouflage, leaving only distinctive bare black spots exposed. When threatened, they secrete a toxic red fluid containing holothurin to deter predators.
MarineReef-DwellerDetritivore
Licensed referencePhilippe Bourjon / CC BY-SA 3.0 · cc-by-sa
—observations
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—peak records
Least ConcernConservation statusIUCN Red List categoriesLCNTVUENCREWEXLeast ConcernRed List categories, explained →
Diet & prey
- Detritus
- Microalgae
- Bacteria
Predators
- Sea stars
- Crabs
- Large predatory fish
ThreatsOverharvesting for the luxury seafood trade, habitat degradation, and ocean acidification
HabitatsShallow coral reefs, seagrass beds, and sandy lagoons
Life span5 to 10 years
Size / weightNot available
Classification
- FamilyHolothuriidae
- SpeciesHolothuria atra
Range data is not available yet.
Interaction riskHigh
- Low
- Moderate
- High
- Very high
- Why interaction risk is high
- Releases toxic holothurin when stressed, which irritates skin and eyes; avoid handling.
- Why it is dangerous
- Secretes a toxic chemical called holothurin when stressed, which causes painful skin irritation and can lead to blindness if rubbed into the eyes.
- How to recognize a risky encounter
- Recognized by its sausage-like, matte black body, which is often covered in sand except for a few circular bare patches.
- What to do
- Observe these creatures without touching; if accidental contact occurs, wash hands immediately and do not touch your eyes.
Responsible observation
- Look for sand coatings: Spot them by looking for sausage-shaped mounds of sand with distinct black patches where the sand did not stick.
- Observe from above: Watch their slow feeding movements through clear, shallow water without disturbing the substrate.
- Do not touch: Avoid picking them up to prevent them from expelling toxic fluids or stress-induced self-evisceration.
Image unavailableFrequent Companion Reef Competitor 
Close Relative (c) Leon Perrie, some rights reserved (CC BY), uploaded by Leon Perrie · cc-by
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