Characteristics
- Primarily these organisms have radial symmetry, but can also be biradial.
- Diploblastic, tissue organization.
- Cnidarians have a gastrovascular cavity. It functions in both digestion and circulation. Also, it is able to function as a hydro-static skeleton. The gastrovascular cavity has an opening to the external environment.
- In between a Cnidarian's epidermal and gastrodermal tissue layer lies in the gelatinous mesoglea.
- Cnidarians have a nervous system in the form of a nerve net.
- The organisms have cnidocytes; which are specialized cells used in defense, feeding, and attachments.
- Some of these organisms have tentacles that help in feeding, locomotion, and defense.
- Cnidarians have two body forms, the medusa and polyp.
- Are polymorphic, meaning these organism alternate between body forms (polyp and medusa).
- These organisms can be colonial or solitary.
- Are dioecious organisms.