| Porifera | Cnidaria | |
| 1. | Cellular level of organization, ostia present | Tissue level, cnidoblasts present |
| 2. | Tissue level, choanocytes present | Organ level, nematocysts present |
| 3. | Diploblastic, spongocoel present | Triploblastic, gastrovascular cavity present |
| 4. | Radial symmetry, hermaphrodite | Bilateral symmetry, unisexual |