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