Phylum Mollusca is a classification of animals that consists of 93,000 known species. It is a highly diverse group living in freshwater, marine and also terrestrial biotopes.
Various species in this phylum are very important to the human beings. Clams and Mussels are an important food source in different parts of the world. Octopuses, squids, whelks, oysters and scallops are also eaten by the human beings. They form an important part of the fisheries and agricultural industry.
Most of them have shells and have the ability to produce pearls.