ABSTRACT
This chapter provides a brief introduction to, and overview of, the gastropods. Gastropods live in nearly all biotic habitats; their greatest diversity is in marine environments, but there are also many non-marine species, particularly in the terrestrial realm. Gastropods are crucial ecologically and are also important economically as sources of food, and their shells are used as ornaments. Gastropods have also been significant in many ecological, evolutionary, biomechanical, physiological, behavioural, and biological studies. The old concept of ‘prosobranchs’ comprises several very distinct groups – Patellogastropoda, Vetigastropoda, Neritimorpha, Caenogastropoda while a few ‘mesogastropod’ groups are basal members of Heterobranchia. Gastropods typically move about on a large ‘foot’ and in that way resemble chitons. Most gastropods have a single shell that is of considerable importance in protecting the animal from predation, desiccation, or other harmful effects and is often the main feature used in identification. Shell attachment muscles in other molluscs are typically paired, but most gastropods have a single ‘columellar’ muscle.
