Asymmetric: When any plane passing through the centre does not divide the body into equal halves, the organism is said to be asymmetric, e.g., sponges. Most of the sponges are  asymmetrical.

Radially symmetrical: When any plane passing through the central axis of the body divides the organism into two identical halves, it is called radial symmetry and the organisms possessing it are called radially symmetric. For e.g., some sponges, coelenterates, ctenophores, adult echinoderms.

Bilaterally symmetrical: When the body can be divided into identical left and right halves in only one plane, it is called bilateral symmetry and the animals possessing this type of symmetry are called bilaterally symmetric.