Velella - Sail-by-the-wind

Velella is the common name of a specific genus of sea creature. There is only one known species within the genus and is a free-floating hydrozoan. They live on the surface of the ocean. This animal is endemic to virtually all the seas and oceans of the world. Just as with the jellyfish, each Velella is, in fact, a hydroid colony. Adult individuals average roughly 2.8 in (7 cm) across. They are carnivorous in nature and their primary diet consists of plankton. Their movements are controlled by the ocean winds. These catch the sail-shaped fin on the surface and move them across the surface.