Upside-down jellyfish

Description:

Cassiopea is a genus of true jellyfish and the only members of the family Cassiopeidae. They are found in warmer coastal regions around the world, including shallow mangrove swamps, mudflats, and turtle grass flats in Florida. The medusa usually lives upside-down on the bottom, which has earned them the common name. Where found, there may be numerous individuals with varying shades of white, blue, green and brown. (information from Wikipedia)

Notes:

This spotting took place at Henry Doorly Zoo. The jellyfish turn upside-down to allow their oral arms to point to the surface of the water, where they can be exposed to sunlight. This allows algae to grow on them and that supplies them with nutrients. (from the zoo sign)