Cassiopea

Cassiopea (upside-down jellyfish) is a genus of true jellyfish in the family Cassiopeidae. They are found in warmer coastal regions around the world, including shallow mangrove swamps, mudflats, canals, and turtle grass flats in Florida, the Caribbean and Micronesia. The medusa usually lives upside-down on the sea floor in shallow areas, which has earned them their common name. They have a symbiotic relationship with photosynthetic dinoflagellates and therefore must lie upside-down in areas with sufficient light. Where found, there may be numerous individuals with varying shades of white, blue, green, and brown. They have distinctive methods of reproduction and prey capture, and are unusual in that they appear to sleep despite lacking a brain. At least one species has been found to release stinging cells in its mucus.