"Invertebrates are animals that neither possess nor develop a vertebral column (commonly known as a backbone or spine), derived from the notochord. This includes all animals ...
[Read more]
apart from the subphylum Vertebrata. Familiar examples of invertebrates include arthropods (insects, arachnids, crustaceans, and myriapods), mollusks (chitons, snails, bivalves, squids, and octopuses), annelids (earthworms and leeches), and cnidarians (hydras, jellyfishes, sea anemones, and corals).
The majority of animal species are invertebrates; one estimate puts the figure at 97%. Many invertebrate taxa have a greater number and variety of species than the entire subphylum of Vertebrata." - (en.wikipedia.org 16.09.2019)