Blue sea star
Linckia laevigata
Spiny Starfish
Marthasterias glacialis
About
The spiny starfish is a large, tough starfish of rocky and muddy seabeds. Its bristling arms make it easy to spot next to the smoother starfish around it.
- Depth
- up to 180 m
How to tell it apart
People often mix this species up with the northern starfish. Check the spine pattern on the arms: this species has three neat, tidy rows, not a scattered layout.
Appearance
It has a small central disc and five thin arms that taper toward the tips. Each arm has three rows of short, cone-shaped, whitish spines running down its length, often tipped with purple. A small ring of pedicellariae, tiny pincer-like parts used for defence and cleaning, surrounds each spine. Its base colour can vary, from brownish or greenish-grey to shades of yellow, red, or purple at the arm tips.
Habitat
It lives on both sheltered muddy-sandy bottoms and rocky ground, from just below the tide line down to about 180 m. It lives across the eastern Atlantic, from Iceland and Macaronesia in the north, into the Baltic and Mediterranean seas, and around parts of the British Isles and Ireland.
Did you know?
This starfish carries defence chemicals called saponins in its body, which it can use against prey and rivals. At low levels they make a whelk back away. At higher levels they cause the whelk's muscles to spasm. Nearby sea urchins react too: one kind flees, while another fights back with its own toxic pincers.
Log it in Into the Blue
Describe what you saw and we name it, then keep every species you find in your Oceandex.
