Flower urchins resemble delicate aquatic blossoms due to hundreds of petal-like pedicellariae that cover their outer shell instead of prominent protective spines. These specialized pincers open and close constantly, ready to snap shut and inject severe, paralyzing venom if disturbed. By day, individuals often disguise themselves beneath bits of coral rubble, shells, and seagrass held tightly against the body with their tube feet.
VenomousMarineReef Dweller
—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Key facts
Diet & prey
Benthic Algae
Bryozoans
Organic Detritus
Predators
Triton's Trumpet
Triggerfish
Pufferfish
ThreatsHabitat degradation, ocean acidification, and water pollution
HabitatsCoral reefs, seagrass beds, and sandy or rocky substrates
Life span10–15 years
Size / weightNot available
Classification
OrderCamarodonta
FamilyToxopneustidae
GenusToxopneustes
SpeciesToxopneustes pileolus
Range & activity
Range data is not available yet.
Safe observation
Interaction riskVery high
Low
Moderate
High
Very high
Why interaction risk is very high
Delivers a medically dangerous, agonizing sting via venomous pedicellariae; never touch or handle.
Why it is dangerous
Flower-like pedicellariae inject toxins such as contractin A and peditoxin, causing intense pain, muscular paralysis, breathing difficulty, and risk of drowning.
How to recognize a risky encounter
Look for a rounded body blanketed by dense, petal-shaped pincers colored pinkish-white to yellowish-green with red centers, often camouflaged under shell fragments.
What to do
Never touch or step on this urchin; seek emergency medical care immediately if stung and submerge the wound in non-scalding hot water.
Responsible observation
Maintain Clearance: Keep hands, fins, and equipment at least half a meter away when snorkeling or diving over reef flats.
Watch Debris: Scan rubble patches carefully, as individuals often disguise their flower-like pincers under loose shells and stones.
No Handling: Never pick up or prod this urchin, even while wearing thick dive gloves.
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