Once a month we will be sharing a marine species reported via the Fair Isle Marine WhatsApp group. This group is a space for community members and visitors to the isle to share any interesting marine finds. These reports also contribute to marine species records for Fair Isle to help monitor changes in biodiversity.
This month we have this lovely cushion star Asterina gibbosa which was found during a group rockpooling session at Muckle Uri Geo, organised by FIMRO’s education officer David.
Cushion stars are commonly found in rock pools across British shores, often hiding on the underside of rocks. As echinoderms, they are characterised by their spiny skin and five short arms, which give them their distinctive, chunky, cushion-like appearance. Cushion stars can grow up to 5 cm in diameter and live for up to seven years.
Cushion stars have a small, circular mouth on their underside which, along with their tube feet, they use to move along the seafloor and scrape algae from surfaces, which makes up the majority of their diet. However, they are also known to feed on harder-to-digest foods, such as dead crabs and sponges. To do this, they use an eversible stomach, which they can push out through their mouth to digest food externally before drawing it back into their body.
David Parnaby