An animal with radial symmetry really has no right and left side or head and rear end. This animals do not move, so they can reach into their environment on all sides. Starfish is an example of radial symmetry. They can be attached to a substrate, like the sea anemone, or floating, like jellyfish. It also occurs in simple animals including the aquatic cnidarians, which include hydra, corals, jellyfish and sea anemones, and Ctenophora, which are comb jellies.
One of the common traits amongst the cnidarians is their symmetry. Hydras, like all cnidarians, display radial symmetry.