by the wind sailor

''Velella'' is a cosmopolitan genus of free-floating hydrozoans that live on the surface of the open ocean. There is only one known species, ''Velella velella'', in the genus. ''Velella velella'' is commonly known by the names sea raft, by-the-wind sailor, purple sail, little sail, or simply ''Velella''.

These small cnidarians are part of a specialised ocean surface community that includes the better-known cnidarian siphonophore, the Portuguese man o' war. Specialized predatory gastropod.. more