The cushion star (Culcita novaeguinea), like all sea stars, moves on a system of tube feet, which are operated by a hydraulic system controlled by the main body. They have been observed feeding on corals and other sedentary animals, as well as decaying organic matter. They feed by inverting their entire stomach through the mouth and digesting soft tissue from a coral's skeleton or clam meat right in the open environment, sucking down the available nutrients. Cushion stars reproduce by broadcast spawning, which involves several females releasing eggs and several males releasing sperm into the water column above the sand at the same time. This method increases the chances that eggs will be fertilized successfully and that fertilized eggs will not be eaten by egg predators near the reef.
Colors in this species range from orange to red to brown to green. Cushion stars are not eaten, but they are collected and dried before being sold in tourist shops. It is unknown what effect this activity has on cushion star populations. Scientists do not have enough data to determine this species' population trends, but because it lives on coral reefs, human-caused changes to this vulnerable ecosystem may endanger the cushion star and other species.
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