Members of the family Oculinidae are characterised by having the walls of the corallites being composed of solid walled though rather fragile tubes connected by a smooth skeletal material called coenosteum. The corallites are widely spaced and robust. The septa curve noticeably outward giving the coral a spikyappearance. Many species in this family form a symbiotic relationship with the flagellateprotozoazooxanthellae which live within the tissues of the polyps. These are photosyntheticalgae that provide nutrients for the polyps while themselves benefiting from a safe environment and an elevated, sunny position.