- Scientific name: Marthasterias glacialis
- Size: Usually up to 30cm across but can be over double this size.
- Distribution: Mostly found around the western coast of Britain and Ireland, and throughout European waters.
The spiny starfish is found around most of Europe, with its range extending to the northern coast of Africa. In UK waters it is much more common to the south and west of the British Isles. It is usually black, green or brownish in colour with multiple rows of lighter tooth-like spines running along its arms. It is a large starfish species, often being 30cm across, with some individuals being double this size, or even larger. They feed on shellfish beds and may also consume other small marine creatures and dead organic matter.