Introduction
Over 95 percent of the animals are invertebrates, the animals who do not have a backbone, who range in size in a large variety. The remaining 5 percent of animals are vertebrates, including fishes, amphibians, reptiles, birds, and mammals, who have a backbone.
Phylum Porifera, Cnidaria, Ctenophora, Platyhelminthes, Annelida, Anthropoda, Mollusca, and Echinodermata are invertebrates while all the vertebrates belong to the sub-phylum Vertebrata.
Phylum Porifera, Cnidaria, Ctenophora, Platyhelminthes, Annelida, Anthropoda, Mollusca, and Echinodermata are invertebrates while all the vertebrates belong to the sub-phylum Vertebrata.