Beautiful Feather Star

Overview

The Beautiful Feather Star (Himerometra robustipinna) is a striking crinoid often found in tropical reef environments. These solitary animals are known for their vibrant coloration and complex, bush-like appearance, frequently positioning themselves in areas with active water currents.

Appearance

This species typically features a central, cup-shaped body from which 33 to 62 long, feathery arms extend. While often a uniform reddish or maroon color, some individuals may display pale brown or yellowish body segments contrasted by dark red pinnules. The arms, which can reach lengths of approximately 20 cm, are lined with fine, hair-like pinnules that give the animal its characteristic plume-like look. To anchor themselves to corals or other hard substrates, they utilize specialized, hook-like appendages called cirri.

Distribution & habitat

Himerometra robustipinna is widely distributed across the Indian Ocean and the western Pacific, ranging from the Bay of Bengal and the Great Barrier Reef to the Philippines and southern Japan. They are typically found in reef habitats, often clinging to hard corals where they can easily capture passing nutrients.

Feeding

As suspension feeders, these feather stars extend their arms into the water column to trap food. They use a sticky substance on their pinnules to capture plankton, detritus, and other organic particles, which are then transported to the central mouth via specialized grooves along the arms.

Biology & behavior

While they are capable of free-swimming, they are most commonly observed clinging to substrates. Their life cycle begins as free-swimming larvae that eventually settle and develop a stalk. As they mature, they detach from this stalk to become free-living adults. They are sometimes found hosting small symbiotic organisms, such as crinoid shrimp, which may mimic the star's coloration for camouflage.