- Gastropods and Bivalve belong to the same phylum : Mollusc , but in different classes due to very striking differences.Class : GastropodSymmetry* * * The gastropods are asymmetrical and covered with a usually coiled shell.Habitat They are both aquatic and terrestrial.Respiration The aquatic gastropods have gills while in terrestrial gastropods the mantle cavity is converted into lungs.Example * garden snail and slug.
Class: Bivalve * Symmetry * these animals are bilaterally symmetrical. Their body is laterally compressed and is enclosed in two pieces of shells.Habitat bivalve are aquatic animals.Respiration The process of respiration is carried out by plate like gills. Example marine mussel and oyster
