- Have specialised cells called Cnidocytes that are used to capture prey
- Solely aquatic
- Have a simple nervous system
- May be Polyp - nonmotile, or Medusa - motile.
- Some show Alternation of Generation between the two.
- Sub-Phylum: Medusozoa
- Sub-Phylum: Myxozoa
- Cnidarians can reproduce both sexually and asexually.
- Some Cnidarians have the ability to do both.