Q Mollusc identity card. How are molluscs characterized according to examples of representing beings, basic morphology, type of symmetry, germ layers and coelom, excretory system, digestive system, respiratory system, circulatory system, nervous system and types of reproduction?
Examples of representing beings: squids, snails, octopuses, sea slugs, mussels, oysters. Basic morphology: soft body, with or without calcareous shell, Type of symmetry: bilateral, Germ layers and coelom: triploblastics and coelomates, Digestive system: complete, Respiratory system: branchial or, in terrestrial gastropods, lungs, Circulatory system: open or, in cephalopods, Nervous system: ganglial, closed. Excretory system: nephridia. advanced cephalization in cephalopods. Kind of reproduction: sexual.