Hydrozoa

Example:Both Hydrozoa and anthozoans, which are Cnidarians, play important roles in marine ecosystems.

Definition:A marine or freshwater animal belonging to the phylum Cnidaria, characterized by stinging cells and often forming colonies.

Example:Zooids within the class Hydrozoa exhibit diverse developmental stages within the same colony.

Definition:A small, simple animal living in colonies, commonly found in the phylum Cnidaria.