Phylum: Mollusca, its classification and characteristics
multicellular, triploblastic, system grade of body organization. mostly bilaterally symmetrical except gastropods. mostly marine, some are found in fresh water whereas some are terrestrial. body is soft and unsegmented. body is divided into head, foot and visceral mass. body enclosed in shell formed of calcium carbonate. shell may be external, internal, reduced or absent. locomotion … Read more