Molluscs characterization

Question

According to examples of representing beings, how are molluscs characterized, fundamental morphology, kind of symmetry, germ layers and coelom, respiratory system, digestive system, excretory system, circulatory system, nervous system and kinds of reproduction?

Answer 1

Examples of representing beings: snails, sea-slugs, octopuses, squids, mussels and oysters. Fundamental morphology: soft body, with or devoid of calcareous shell. Kind of symmetry: bilateral. Germ layers and coelom: triploblastics and coelomates. Digestive system: complete. Respiratory system: branchial or, in the terrestrial gastropods, lungs. Circulatory system: open or, in cephalopods or closed. Excretory system: nephridia. Nervous system: ganglial, advanced cephalization in the cephalopods. Kinds of reproduction: sexual.