Blue button

Porpita porpita

Family Porpitidae - hydroids

Colonial polyps consisting of a whitish to golden brown circular floating disk with up to 100 cocentric (circling) and radiating air chambers, chitinous, texture is like styrofoam; surface edges of disk with darker color (blue or green); edges of disk with attached blue or green tentacles (actually hydroid polyps), short, medium and long; each tentacle has small branches starting about halfway down its length, each branch ends in a node of stinging cells; a mouth is located underneath its disk.
Similar Species
Very similar to the by the wind sailor (Velella velella) but without the sail and with longer tentacles.
Gulf, floats on the surface
Maximum Size
disk up to 5 cm (2 in)
Other Common Names
Previous Scientific Names