The animals without a vertebral column in their body are called Invertebrate. Unicellular organisms are also divided into this Invertebrate. They have a single cell. The invertebrates animals are classified into 9 phyla. They are listed below:
| Phylum | Examples |
|
Porifera
|
Sponges |
| Cnidarians | Jellyfish, corals, anemones, hydra |
| Platyhelminthes | Flatworms, flukes, tapeworms |
| Echinodermata | Sea stars, brittle stars, sea urchins, sea cucumbers |
| Mollusca | Snails, clams, squids, octopi, other mollusks |
| Nematoda | Ascaris, vinegar eels, hookworms, nematodes, pinworms |
| Arthropoda | Crabs, scorpions, insects, spiders, millipedes, centipedes, barnacles |
| Annelida | Earthworms, leeches, lugworms |
| Chordata | Sea squirts, lancelets |
