Porpita is a colonial hydrozoan which lives floating on the sea surface. The polyps are arranged concentrically on the lower surface of a hard, chitinous central disk. There is a large central polyp (gastrozooid) around of which are arranged numerous gastro-gonozoids, polyps responsible for food intake and production of jellyfish. The dactilozooids are the polyps responsible for capturing food and defense, being located more externally.
Recruitment panels being processed in the field. These plates remain submerged and communities develop only on the underside, where there is no sedimentation.