<P> Pentamerism, another variant of radial symmetry (also called pentaradial and pentagonal symmetry), means the organism is in five parts around a central axis, 72 ° apart . Among animals, only the echinoderms such as sea stars, sea urchins, and sea lilies are pentamerous as adults, with five arms arranged around the mouth . Being bilaterian animals, however, they initially develop with mirror symmetry as larvae, then gain pentaradial symmetry later . </P> <P> Flowering plants show fivefold symmetry in many flowers and in various fruits . This is well seen in the arrangement of the five carpels (the botanical fruits containing the seeds) in an apple cut transversely . </P> <P> Hexamerism is found in the corals and sea anemones (class Anthozoa) which are divided into two groups based on their symmetry . The most common corals in the subclass Hexacorallia have a hexameric body plan; their polyps have sixfold internal symmetry and the number of their tentacles is a multiple of six . </P> <P> Octamerism is found in corals of the subclass Octocorallia . These have polyps with eight tentacles and octameric radial symmetry . The octopus, however, has bilateral symmetry, despite its eight arms . </P>

When are the body orientation and symmetry established