The giant basket star (astrophyton muricatum) is an early Mesozoic invertebrate, often found around British Virgin Islands.
During the day, it curls up into a tight ball shape to protect itself from predators. At night, it climbs to an elevated point to feed on plankton by extending its intricately-branched feeding arms in a bowl-like shape. Then, it coils around its prey and the tiny hooks along the length of these arms will prevent its prey from escaping.
Astrophyton are in no way related to Astrophytum, which are a genus of cacti.