Summary:
- Echinoderms are marine organisms that make up the phylum Echinodermata.
- They can be found in the ocean from the equator to the poles.
- They are among the most distinctive organisms within the animal kingdom.
- Members of the phylum include sea stars (starfish), sand dollars, and feather stars.
- Echinoderms are named for their spiny skin, which is covered by a thin layer of calcium carbonate plates and spines.
- Adult echinoderms have radial symmetry, but larvae have bilateral symmetry.
- Echinoderms have a unique water vascular system, with canals that extend along each body part.