Coelenterata

• They are diploblastic animals , in which, the body is made up of two layers of cells:
• Ectoderm – One layer makes up the cells outside the body
• Endoderm – the other forms the inner lining of the body.
• These are mostly aquatic or marine habitat animals.
• Body shows radial symmetry.
• They have cavities in their body. Body cavity (coelom) acts as gastrovascular cavity i.e. coelenteron.
• Respiratory, circulatory and excretory organs are absent .
• They have a tissue level of organisation.
• Sessile forms are called Polyps and free-living forms are called Medusa.

For example : Hydra, Sea anemone