Invertebrate

Reticulated Sea Biscuit

Clypeaster reticulatus

Also known as Reticulate Sea Biscuit, Net-marked Sea Biscuit

Reticulated sea biscuits are burrowing irregular sea urchins with flattened, pentagonal tests carpeted in tiny spines that plow through sandy ocean floors. They live partly or completely buried in loose sediments, using specialized tube feet to sort organic detritus and microalgae from sand grains. Their empty tests, often washed ashore with a distinctive five-petaled floral pattern, reveal the intricate internal skeletal supports that withstand crushing surf.

MarineBurrowingEchinoderm

—observations

—countries

—peak records

Not EvaluatedConservation status

Key facts

Diet & preyBenthic diatoms, Organic detritus, Microscopic algae

Predators

Helmet snails
Triggerfish
Sea stars

ThreatsCoastal habitat degradation, bottom trawling, and souvenir shell harvesting

HabitatsShallow tropical and subtropical sandy sea floors and reef lagoons

Life span5–10 years

Classification

OrderClypeasteroida
FamilyClypeasteridae
GenusClypeaster
SpeciesClypeaster reticulatus

Range & activity

Range data is not available yet.

Safe observation

Interaction riskLow

Low
Moderate
High
Very high

Why interaction risk is low: Safe to observe at a normal distance.

Responsible observation

Tidepool etiquette: Leave living specimens undisturbed in the sand, as lifting them exposes them to desiccation and predators.
Shell collection: Check thoroughly to ensure any washed-up test is completely empty and no longer living before handling.