Invertebrates
Cushion Star
Culcita spp. · also called pincushion starfish
Resting on a patch of reef sand, a cushion star looks more like a stray, brightly coloured pillow than any recognisable sea star, its arms so short and its body so puffy that a first glance rarely identifies it correctly at all.
Overview
The cushion star, genus Culcita, is a thick-bodied sea star found across coral reef and sandy habitat in the Indo-Pacific region. Its unusually puffy, short-armed adult shape, so different from the typical star outline, makes it one of the more visually distinctive and easily misidentified echinoderms on any reef.
A starfish that outgrew its own shape
As a cushion star matures, it steadily leaves the familiar star-shaped silhouette behind, settling into a rounded, pillow-like form that makes it one of the few sea stars genuinely difficult to identify as a sea star at first glance.
Status
Least Concern — widespread and common across suitable coral reef habitat throughout the Indo-Pacific region.
Cushion Star: common questions
Why doesn't the cushion star look like a typical starfish?
A cushion star has a notably thick, puffy, pillow-like body with very short or barely visible arms, a shape that develops as the animal matures, since a juvenile cushion star typically looks more clearly star-shaped before its arms shorten dramatically and its body rounds out into the cushion-like form adults are known for.
How does a cushion star eat?
A cushion star feeds by extending its own stomach directly onto food on the reef surface, digesting algae, detritus, and small invertebrates externally before drawing the digested material back into its body, a feeding method shared broadly among sea stars.
Why is the cushion star popular with aquarium keepers?
The cushion star's unusual rounded, pillow-like shape and often bright colouration have made it a popular species in the marine aquarium trade, valued for looking visually distinct from the more typical star-shaped sea stars most people expect to see.
Where does the cushion star live?
The cushion star is native to coral reef and adjacent sandy habitat across the Indo-Pacific region, moving slowly across these surfaces using rows of small tube feet on its underside.