Class: BivalviaCollection Highlights | Updated 5 years ago Amusium pleuronectes Image copyright of WA Museum The word “bivalve” means that the shell has two valves that generally enclose the entire body. These valves are dorsally hinged and are secreted by a large, two-lobed mantle. Bivalves lack a defined head and a radula (a rasp-like ribbon used to tear up food and draw it into the mouth – common to most molluscs). Most are stationary filter feeders, feeding on minute particles of algae and detritus. Bivalves include Giant Clams, Oysters, Scallops and Mussels. Mollusc (Malacology) Section View the discussion thread.