Description
This starfish has five thick arms, on the top side covered with spines. On the bottom side there are numerous tube feet, used for moving and gripping. The mouth lies centrally on the bottom side. When feeding it appears to stand on the tip of its arm. It will cling to its prey and revert its stomach over it. It mainly feeds on mussels and other clams, but will also eat carrion.  It will grip the shell, keep it closed until the prey is gasping from exhaustion and lack of oxygen. After that it is easy to open and revert its stomach into it. The common starfish have separated sexes, and they reproduce by releasing sperm and eggs into the water simultaneously. The larvae are pelagic.

Size
The maximum size is 300 mm.

Colour
Varying from pink, orange, yellow to purple.

Habitat
Mostly on hard substrate from the shallows up to depths of 650 meters.

Distribution
Eastern Atlantic, from Iceland and the White sea in the north, to Senegal in the south.