2.1 TAXONOMY AND ANATOMY

2.1.1 Introduction

Some knowledge of bivalve biology is necessary to understand operations of a bivalve hatchery and to assist in solving problems that arise.

It is not the intention here to give a detailed description of bivalve biology but to provide a brief resume of information pertinent to operations of a hatchery. There are several excellent texts on molluscan biology readily available and there are extensive reviews of groups and individual species of oysters, scallops, mussels and clams. The reader is directed to these publications at the end of this section for additional information.
Bivalves belong to the phylum Mollusca, a group that includes such diverse animals as chitons (chain shells), gastropods, tusk shells, cephalopods (squid and octopus) as well as clams, oysters, mussels and scallops. The phylum has six classes of which one is Lamellibranchia or Bivalvia. These animals are compressed laterally and the soft body parts are completely or partially enclosed by the shell, which is composed of two hinged valves. The gills or ctenidia of animals in this class are well developed organs, specialized for feeding as well as for respiration.