Comparison of various Invertebrate Phyla with Chordates
| Characteristics | Porifera | Cnidaria | Platyhelminthes | Nematoda | Bryozoa | Brachiopoda | Annelids | Arthropods | Mollusks | Echinoderms | Chordates |
|---|
| Cell Layers | 2 | 2 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
| Segmentation | none | none | none | none | none | none | have | have | none | none | have |
| Body cavity | None | None | None | Pseudocoelom | Coelom | Coelom | Coelom | Coelom | Coelom | Coelom | Coelom |
| Skeletal/Support | Endoskeleton | Exoskeleton | None | None | Exoskeleton | Exoskeleton | None | Exoskeleton | Exo/endoskeleton | Endoskeleton | Endoskeleton |
| Muscular system | None | Have | Have | Have | Have | Have | Have | Have | Have | Have | Have |
| Digestive System | None | Incomplete | Incomplete | Complete | Complete | Complete | Complete | Complete | Complete | Complete | Complete |
| Digestive System | Intracellular | Extracellular | Extracellular | Extracellular | Extracellular | Extracellular | Extracellular | Extracellular | Extracellular | Extracellular | Extracellular |
| Circulatory system | None | None | None | None | None | Open | Closed | Open | Open | Open/Closed | Closed |
| Respiration | Diffusion | Diffusion | Diffusion | Diffusion | Lophophore | Lophophore | Gills | Gills/Trachea | Gills | Gills | Gills/Lungs |
| Excretory | None | None | Present | Present | None | Present | Present | Present | Present | None | Present |
| Reproduction | Asexual/Sexual | Asexual/Sexual | Asexual/Sexual | Asexual/Sexual | Sexual | Sexual | Sexual | Sexual | Sexual | Sexual | Sexual |
| Nervous system | None | Present | Present | Present | Present | Present | Present | Present | Present | Present | Present |
| Sensory organs | None | Have | Have | Have | Have | Have | Have | Have | Have | Have | Have |
| Symmetry | Asym./Radial | Radial | Bilateral | Bilateral | Bilateral | Bilateral | Bilateral | Bilateral | Bilateral | Penta./Bilateral | Bilateral |
| Appendages | None | Tentacles | None | None | Tentacles | Muscular foot | Parapodia | Legs/wings | Muscular foot/tentacles | "Arms" | Legs/wings |
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