There are several species of brittlestar found in British seas, which can be difficult to tell apart. Common brittlestars vary in colour, from dull brown to purple, red, orange and yellow. Their spiny legs are patterned with coloured bands.
Their fragile arms are often broken off if found in rockpools – a sign of past disturbance or predation.
Behaviour
Brittlestars are related to starfish and have a rounded disc-like body with 5 long, thin flexible arms. They really do live up to their name and will shed parts of their arms if they are disturbed or feel threatened. So look but don’t touch!
Common brittlestars are found all around our coasts, in rockpools in the lower shore and offshore to depths of 85m. They live on the seabed and raise their long legs into the water current to filter feed, catching plankton and detritus.
They are often found in dense aggregations where food is plentiful – with numbers of 2000 per square metre recorded.
Size
Diameter: up to 2cm Average Lifespan: 5-10 years
Status
Common.
Distribution
Found all around our coasts, but distribution is patchy on East Coast of England and Scotland.
When to see
January to December
Facts
Brittlestars are often eaten by their larger relatives, the common starfish and the spiny starfish. They hide in cracks and crevices to avoid being eaten, but can also detect a type of chemical produced by their starfish predators and so will move away!