There is an order of animal classifications, starting with Domain, and then going to Phylum, Class, Order, Family, Genus, and then species.
The class Asteroidea is the largest in the phylum Echinodermata. It contains approximately 1600 extant species and are commonly known as starfish.
Fish belong to the Chordata phylum.
the phylum is chordata and the class would be mammalia.
polychaeta