Upside-down Jellyfish

The upside-down jellyfish, genus Cassiopea, is found in shallow, warm coastal waters such as mangroves and lagoons, named for its unusual habit of resting bell-down on the sea floor with its frilled oral arms facing upward toward the sun. This orientation lets its arms, which host symbiotic photosynthetic algae similar to those in corals, capture sunlight, supplementing its diet with nutrients the algae produce; it can swim but spends most of its time nearly motionless in this inverted position, gently pulsating its bell.