Ophidiaster · Echinoderms (Starfish, Urchins & Brittle Stars)

Purple Seastar

Ophidiaster ophidianus

0-40m

Depth Range

Variable

Max Size

Mediterranean

Distribution

Echinoderm

Identification & Biology

IdentificationA large, distinctive starfish with five long, smooth, cylindrical arms and a vivid purple to reddish-purple colour. The surface is smooth and leathery without obvious spines. One of the most colourful starfish in the Mediterranean.
SizeArm span up to 40 cm. A large and conspicuous species.
Social HabitSolitary. Slow-moving. Found on open rocky surfaces, walls, and cave entrances. Not shy and often seen in exposed positions.
HabitatRocky reefs, walls, and cave entrances. Prefers hard substrates with good water flow.
Depth5 to 100 m. Most common between 10 and 50 m.
Feeds OnSponges, bryozoans, and other encrusting organisms. A slow predator that digests prey externally by everting its stomach.
DistributionMediterranean Sea and adjacent eastern Atlantic (Macaronesian islands). Present in Maltese waters.
DescriptionOphidiaster ophidianus is the most striking starfish in the Mediterranean, its vivid purple colour making it a standout on any reef. Unlike many starfish that are hidden or camouflaged, this species is often found in plain view on open rock faces and walls. It is slow-growing and long-lived. It is a protected species under Annex II of the Barcelona Convention.

Range

Habitat & Distribution

Found across the Mediterranean, inhabiting reef & open environments. Active from the surface down to 40m depth.

Where Malta divers have spotted this species

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Sightings are logged by divers using our What Did You See? dive-log tool. View the full live sightings map.

Detail

Preferred Environment

Reef & Open habitats, typically at depths of 0-40m. Most commonly encountered by divers at the shallower end of its range.

Encounter Tips

Best approached slowly and calmly. Avoid casting shadows directly over the animal. Neutral buoyancy and patience increase encounter success significantly.

Biology

Behaviour & Diet

Feeding Strategy

Predatory starfish that feeds on bivalves, gastropods, and other invertebrates. Pries open shellfish with sustained tube-foot pressure and everts its stomach into the gap to digest prey externally.

Mollusc predator

Reproduction

Sexes are separate, with external fertilisation following synchronised spawning events. Planktonic bipinnaria larvae settle after several weeks of development.

Broadcast spawner

Behaviour & Defence

Tough, calcified skin with small spines makes it unpalatable to many predators. Can regenerate lost arms over several months if damaged.

Calcified skin

Dive with diveshack

Where to Encounter in Malta

The following dive sites offer strong habitat match for Ophidiaster ophidianus. All are accessible on a guided dive with diveshack.

5-30m

North Malta

Cirkewwa

Rocky reef with caves, arches and ledges hosting a rich diversity of reef species.

View dive site ›

5-50m

Gozo

Blue Hole

One of the Med's most famous reef dive sites. Rocky walls and archways covered in life.

View dive site ›

18-36m

South Malta

Um El Faroud

The wreck lies on a sandy bottom surrounded by rocky reef -- a diverse habitat attracting reef species.

View dive site ›

IUCN Red List Least Concern

Conservation Status

This species is assessed as Least Concern on the IUCN Red List. Mediterranean populations face ongoing pressure from fishing activity, habitat degradation, and climate-driven changes to prey availability.

Source: iNaturalist Guide #888
by Lesley Clements (CC BY-SA)
diveshack Mediterranean Marine Life guide