About Himerometra robustipinna (Carpenter, 1881)
Himerometra robustipinna (Carpenter, 1881), commonly called a feather star, can reach an overall diameter of about 35 to 40 cm (14 to 16 in). It has a cup-shaped central disc, with 33 to 62 arms (most individuals have around 45 arms) that reach about 20 cm (8 in) in length extending out from the disc. Both its mouth and anus are located on the upper side of the body. Most individuals have reddish or maroon arms, but this species may also have yellow or pale brown brachials with maroon pinnules. This feather star feeds on detritus, phytoplankton, and zooplankton that it catches using a sticky substance produced on its arms. It uses short appendages called cirri to cling onto corals, but it is also capable of swimming freely. The larvae of this species swim freely as part of the plankton community for a few weeks, after which they settle and grow into a stalked form. Mature individuals break away from their stalk to become free-living. This species is widespread in the western Pacific Ocean and the Indian Ocean, ranging from the Bay of Bengal to the China Sea, Great Barrier Reef, Indonesia, Philippines, and southern Japan. It inhabits coastal coral reef ecosystems with relatively strong currents, clear water, and available plankton, found at depths between 0 and 57 meters.
