An anthozoan polyp, like polyps in other cnidarian classes, consists of a tubular body terminating in a mouth surrounded by a ring of tentacles. The tentacles of an anthozoan polyp, unlike those of some other classes, are hollow, so the coelenteric space extends into them. The mesoglea between the ectoderm and the endoderm is relatively thick and cellular in many anthozoans compared to that of polyps in the other classes.
Most anthozoan orders contain exclusively colonial species.
An anthozoan colony consists of polyps connected by living tissue, the coenenchyme. At least some individuals of clonal species, like those of colonial species, propagate vegetatively by means such as fission, budding, or laceration, but, unlike in colonial species, the progeny do not remain attached to one another. The actinopharynx, or stomodeum, is a tubular gullet extending from the mouth some distance into the coelenteron. The actinopharynx of most species contains at least one histologically specialized, flagellated longitudinal channel called a siphonoglyph that drives water into the coelenteron. In most sea anemones and corals, two siphonoglyphs are situated diametrically opposite one another in the actinopharynx.