Feather Star

Feather stars anchor themselves to exposed coral heads at Hon Doi Moi using cirri — claw-like appendages on their underside — and extend dozens of feathery arms into the current to filter plankton, their arms rolling and unrolling in response to flow direction. They host a dedicated community of commensal species — crinoid shrimp, crinoid squat lobsters, and crinoid clingfish — whose coloration and patterning matches the feather star's own pigments so precisely that finding them requires dedicated searching. Their abundance on Hon Doi Moi's healthy corals is an indicator of the strong planktonic food supply that supports the site's overall biodiversity.