Dichrometra palmata is a stunning species of feather star (crinoid) belonging to the family Mariametridae. While they may look like delicate underwater plants, feather stars are actually free-moving marine animals related to starfish and sea urchins. This particular species is easily recognized by the beautiful, highly contrasting pattern on its arms, featuring a deep red-brown stripe running down the center and yellowish-white banded pinnules (the "feathers").
A Creature of the Night
Like many feather stars, Dichrometra palmata is strictly nocturnal. During the day, it curls its arms tightly and hides deep inside reef crevices, making it almost invisible to passing divers. But as soon as the sun sets, it crawls to the exposed, current-swept edges of the reef. There, it unfurls its magnificent arms into a wide, bowl-shaped net to filter passing zooplankton from the water column.
A Micro-Habitat for Symbionts
These feather stars are more than just beautiful predators; they serve as a mobile home for a variety of fascinating commensal creatures. If you look very closely at the base of their arms, you might spot specialized crinoid shrimps (such as Laomenes or Periclimenes). These tiny hitchhikers have evolved master-level camouflage, perfectly mimicking the red, brown, and yellow patterns of their host to remain invisible to predators.
