Which organisms possess radial symmetry?

Radial symmetry is a body plan in which the body is organized around a central axis, allowing for multiple lines of symmetry radiating out from that center, much like the spokes of a wheel. Organisms that exhibit radial symmetry can be divided into similar halves by multiple planes passing through their central axis.

Hydra, which is a member of the phylum Cnidaria, exemplifies this type of symmetry. Its body can be arranged symmetrically around its mouth, located at one end, with tentacles surrounding it. This allows the hydra to capture prey efficiently from any direction, making it well-suited for its aquatic environment.

In contrast, insects exhibit bilateral symmetry, which means they can be divided into mirror-image halves only along one plane. Similarly, mammals and earthworms also demonstrate bilateral symmetry, where their body structure allows for a distinct left and right side but not radial symmetry. This difference in symmetry reflects various evolutionary adaptations suited to each group's lifestyle and habitat.