Coelenterata:

Organization: Tissue level

Symmetry:  Radial

Coelom:  Absent

Segmentation:  Absent

Arrangement of embryonic layers:  Diploblastic

Digestive system:  Incomplete (both intercellular and extracellular)

Circulatory system: Absent

Respiratory system:  Absent

Habitat:  Marine and sessile(directly attached to base) and free-swimming.

Sexuality:  Hermaphrodite (sexes are not separate, egg and sperm are produced in same individual).

 Notochord:  Absent

 Reproduction:   Sexual

Distinctive features:

• Their body has two parts; stinging capsule and tantacles.
• Stinging capsule is also called cnidoblasts, that’s why these are also called Cnidaria.
• Cnidoblasts are used for anchorage, defence and to capture food.
• They have a central gastro-vascular cavity with a single opening, mouth on hypostome. Hypostome are appendages on mouth of some insects.
•  Some of them have a skeleton composed of calcium carbonate. They have two basic forms: polyp and medusa.  Polyp is cylindrical (hydra like) and medusa is umbrella shaped (jelly fish like).
•  Both forms exhibit alternation of generation (Metagenesis), i.e., polyps produce medusa asexually and medusa form the polyps sexually.