Invertebrates are animals that do not have a vertebral column, which is otherwise known as the backbone or spinal column. The term was coined by Jean-Baptiste Lamarck to describe this particular characteristic of animals or rather the lack thereof, but is not used as a designation in the taxonomic hierarchy.
Invertebrates include all animals except the vertebrates (i.e. fish, reptiles, amphibians, birds and mammals). Ninety-five percent of the animals in the animal kingdom do not possess a backbone. The invertebrates include important groups such as the crustaceans, insects, arachnids, mollusks, and worms.
- Arthropoda (lobsters, crabs, insects)
- Porifera (sponges)
- Echinodermata (sea urchins, sea cucumbers, starfish)
- Cnidaria (jellyfish, corals, anemones)
- Annelida (earth worms, leeches)
- Platyhelminthes (flukes, tapeworms)
- Nematoda (hookworms, pinworms)
- Mollusca (shellfish, squid, snails, slugs)
- Rotifera (rotifers)
- Ctenophora (comb jellies)
- Invertebrate by Wikipedia