Sea Lilies and Feather Stars: Crinoidea

Sea lilies and feather stars stand upright in the water current and extend their branches so that their food grooves can catch plankton. Feather stars usually live in clumps, attaching themselves to crevices and other places in which they can hide most of their body. Most species come out at night, exposing part or all of their arms, or even the entire body. Sea lilies also live in clusters but because of the lack of light in deep water do not have a day-and-night pattern of coming out.

Feather stars use their arms to crawl. Some swim by alternating their arms up and down. They go down through the water by extending their arms like parachutes. Only a few sea lilies can crawl, and none can swim.

Sea lilies and feather stars can regrow lost body parts. Feather stars can regrow their arms as long as at least one arm and a nerve center are intact. Sea lilies can regrow an entire crown.

Sea lilies and feather stars have separate sexes. The males release sperm into the water, and females of most species release their eggs into the water. In some feather stars, the eggs stay on the female for days and then are released into the water or enter pouches. After joining with sperm, the eggs of almost all sea lilies and feather stars develop into non-feeding, drifting larvae (LAR-vee), which are animals in an early stage that change form before becoming adults. These larvae transform into bottom-dwelling, non-feeding, stalked larvae that transform into bottom-dwelling, stalked young animals. The young are ready to reproduce in twelve to eighteen months.