Echinoderm identity card. How are echinoderms 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: sea cucumber, sea urchin, starfishes. Basic morphology: calcareous endoskeleton with spines, ambulacral system. Type of symmetry: secondary radial. Germ layers and coelom: triploblastics, coelomates. Digestive system: complete, deuterostomes. Respiratory system: nonexistent. Circulatory system: nonexistent. Excretory system: nonexistent. Nervous system: simple, nerve network without ganglia or cephalization. Types of reproduction: sexual, with larval stage.
