Which phylum of animals exhibits bilateral symmetry in the larval stage and radial symmetry in the adult stage?

The water vascular system is a characteristic feature of which of the following phyla?

Identify the phylum in which adults exhibit radial symmetry and larva exhibit bilateral symmetry.

Absence of excretory organs,high power of regeneration,and exclusively marine; these are the characteristics of the phylum:

Starfish belongs to which class?

Assertion : Ambulacral system plays a major role in locomotion of echinoderm.
Reason : Hydraulic pressure of fluid and contraction of muscle of tube feet make possible movement of echinoderm.