Characterization of symmetry and nervous system

Question

Describe the characterization of symmetry and nervous system in echinoderms?

Answer 1

Adult echinoderms, all along with cnidarians, are the animals which present radial symmetry, that is, their body structures are distributed around a center. Radial symmetry in echinoderms though is a secondary radial symmetry, as their larval phase has bilateral symmetry and the radial pattern emerges only in adult individuals (that is, there are few adult echinoderms with lateral symmetry). All other animals contain lateral symmetry with the exception of poriferans (that is, no symmetry is stated for them).

Echinoderms do not existed in cephalization and they contain a diffuse network of nerves and neurons made up of a neural ring around the mouth and of radial nerves which ramify to follow the pentaradial structure of body.