Brittlestar beds
In some places the seabed writhes with a living mat of brittlestars. These
can be as dense as up to 2,000 brittlestars per metre square to the exclusion
of most other animals. If currents become too strong and the brittlestars
are in danger of being swept away, they link arms with their neighbours
and lie flat to the seabed, forming a living carpet. Brittlestar beds can
also be found in areas of less extreme water currents such as headlands
inside sea lochs.