Description: This starfish has five tapering, blunt-tipped, arms covered with small, scattered white spines. Small specimens are quite stiff but larger ones are rather soft and floppy. The white spines form a definite line down the centre of each arm. Between the spines are groups of soft transparent processes called papulae. Body colour is usually brown to pale orange, in some locations this may be masked by blue or purple. In exposed habitats up to 12cm, in more sheltered sites up to 30cm across.

Habitat: The commonest British starfish intertidally and in the sublittoral. Particularly common on mussels in the shallow sublittoral and on soft sediments. One of the few echinoderms which can tolerate brackish conditions.

Distribution: Widespread all around the British Isles.

Similar Species: Leptasterias muelleri is a smaller species and can be distinguished by its firmer spinier texture and characteristic spines.

Key Identification Features:

• Soft floppy texture in larger individuals.
• Central row of white spines along each arm.
• Beige colouring with white spine groups.
• Several papulae in each space between spines.

Distribution Map from NBN: Asterias rubens at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Asterias rubens at iNaturalist World Species Observations database.

WoRMS: Asterias rubens at World Register of Marine Species. Accepted name: Asterias rubens Linnaeus, 1758. AphiaID: 123776.

Classification: Biota; Animalia; Echinodermata; Asterozoa; Asteroidea; Ambuloasteroidea; Neoasteroidea; Forcipulatacea; Forcipulatida; Asteriidae; Asterias