Question

classes of *Hydrozoa * Trematoda *Bivalvia *Polychaeta

Answer 1

Answer:

Hydrozoa itself is a class. Hydrozoa includes nearly 3,200 species; most are marine, although some freshwater species.

Trematoda subclasses: The class is commonly divided into two subclasses, Aspidogastrea and Digenea.

Bivalvia: class Bivalvia - oysters; clams; scallops; mussels Bivalvia, class Lamellibranchia, class Pelecypoda, Lamellibranchia Mollusca, phylum Mollusca - gastropods; bivalves; cephalopods; chitons bivalve, lamellibranch, pelecypod - marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together,

Polychaeta:The Polychaeta, also known as the bristle worms or polychaetes, are a paraphyletic class of annelid worms, generally marine. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin.

Explanation: