Porania pulvillus

(O.F. Müller, 1788)

Body with a large, convex disk and 5 short, wide and tapering arms; up to 110 mm in diameter; R/r: 1.5-2; coloured bright red or yellowish-white, with a white under side.

Dorsal side
The upper surface is smooth and covered with a thick, naked skin, free of any spines or pedicellariae, only scattered groups of papulae. The upper marginal plates are naked and narrow. The lower marginal plates have 3-5 fairly strong spines, forming a distinct fringe along the edge of the body.

Oral side
The oral interradial area is naked, often with distinct radiating furrows. The ambulacral grooves are narrow. The ambulacral plates have one furrow spine and another on the outer surface. These two spines form a regular double series of spines along each side of the ambulacral grooves.

This species is found on muddy substrata, from depths of 10-1000 m.

Along the coasts of the British Isles and Skandinavia. This species is apparently more common in the north.

Asterina gibbosa is similar in shape, but much smaller and often green in colour.