ABSTRACT
Molluscs are bilaterally symmetrical eumetazoans and are one of the major groups (phyla). Molluscs have been an important source of food for man from early times, and as objects they were, and are, incorporated or depicted in art and religion. The branch of biology that studies molluscs is called malacology, and its practitioners are malacologists. Most malacologists can also be referred to by their other areas of speciality – e.g., as ecologists, palaeontologists, anatomists, neurobiologists, molecular biologists, physiologists, taxonomists, conservationists, etc. The study of molluscs began with the fascination with shells as curiosities. Molluscs have evolved to adopt very diverse lifestyles and occur in almost every habitat except free flying in the atmosphere. Molluscs are most abundant and diverse in shallow-water marine ecosystems. Many marine chitons and gastropods scrape a living on hard substrata, possibly in much the same way as the earliest molluscs. The chapter also presents an overview of the key concepts discussed in this book.
