Rosy Feather-star

• It is an echinoderm, a relative of the sea stars and urchins, though its flower-like appearance gives nothing away.
• It swims by beating its arms alternately in a surprisingly graceful motion, something unusual among echinoderms.
• If a predator tears off an arm it regrows it completely, and it can shed arms deliberately to escape.
• Crinoids are the oldest group of echinoderms: they have been in the oceans for more than 480 million years and are abundant in the fossil record.
• Adults of this genus have no stalk. They begin life fixed by one, like the fossil sea lilies, then let go and hold on by their cirri, able to change position and even swim clumsily by beating their arms.
• It filters plankton with its feathery arms spread fanwise against the current, angling them according to where it comes from.
• It regrows whole arms easily, and individuals with arms at different stages of growth are a common sight.

Skeleton type

Invertebrate - endoskeleton of calcareous plates (echinoderm)

Habitat and environment

Rocky bottoms of the north-eastern Atlantic, from 0 to 200 m

Sources consulted: Pennant (1777) · Marine Life Information Network · Nichols (1994) · ScienceDirect (Hughes 1989) · Science Advances, How colonial animals evolve · Wikipedia, Zooid