| Porifera | Cnidaria | Ctenophora |
|------------------------ |------------------------|------------------------|
| Sponge | Jellyfish, Coral | Comb Jelly |
| Asymmetrical | Radial symmetry | Radial symmetry |
| None (skeleton spicules)| Hydrostatic skeleton | None |
| None | None | None |
| Diffusion | Diffusion | Diffusion |
| Simple nerve net | Nerve net | Nerve net |
| Intracellular digestion| Extracellular digestion| Extracellular digestion|
| None | None | Diffusion |
| Monoecious or dioecious| Dioecious | Hermaphroditic |
| Aquatic, filter feeders| Aquatic, predatory | Aquatic, planktivores |
Porifera, commonly known as sponges, are simple aquatic organisms with asymmetrical body forms.
They lack true tissues and organs and are characterized by a primitive level of organization.
Their support system consists of a skeleton made of spicules, providing structural support.
Cnidaria, including jellyfish and corals, exhibit radial symmetry and have a hydrostatic skeleton, allowing them to maintain shape through water pressure.
They lack a true circulatory system, relying on diffusion for nutrient transport.
Cnidarians have a nerve net for basic coordination and often possess specialized cells for sensing the environment.
Ctenophora, exemplified by comb jellies, also display radial symmetry.
They lack a true support system and circulatory system, relying on diffusion for gas exchange and nutrient transport.
Ctenophores have a nerve net for basic coordination and may exhibit bioluminescence.
Their digestive system involves extracellular digestion, and waste elimination occurs through diffusion.
These three phyla represent different levels of complexity in terms of body structure and systems, with Porifera being the simplest and Ctenophora exhibiting some advanced features.