Mediterranean Feather Star

Overview

The Mediterranean feather star is a stalkless crinoid commonly found throughout the Mediterranean Sea. It is a filter-feeding echinoderm that uses its feathery arms to capture plankton and organic particles from the water column.

Distribution & habitat

This species is widespread across the Mediterranean and Aegean Seas, extending westward to the south coast of Spain and Cape St. Vincent. It typically inhabits rocky and sandy bottoms, seagrass meadows, and coralligenous environments, often attaching itself to hard substrates or other invertebrates like sponges and gorgonians in areas with sufficient water current.

Appearance

This crinoid features a small, cup-shaped central body called a calyx, which bears up to forty prehensile, grasping structures known as cirri used for anchoring. Extending from the calyx are ten fragile, feathery arms lined with pinnules. These arms can reach lengths of approximately 10 cm and are capable of regeneration if damaged. The species displays significant color variation, appearing in shades of white, yellow, orange, red, brown, or dark purple, sometimes featuring contrasting bands.

Biology & behavior

While it lives on the seabed, the Mediterranean feather star is capable of movement using its arms. It is a gonochoric species, meaning individuals are either male or female, though they are not externally distinguishable. Fertilization occurs externally in the water column, and females may hold eggs at the base of their pinnules until they hatch into planktonic larvae. The species is known to be a filter feeder, relying on its arms to trap food, which is then transported to the mouth via a specialized comb-like structure on the pinnules.