Characteristics In most adult chordates the notochord disappears or becomes highly modified. In some non-vertebrate chordates and fishes the notochord persists as a laterally flexible but incompressible skeletal rod that prevents telescopic collapse of the body during swimming.
Introduction The Phylum Chordata includes the well-known vertebrates (fishes, amphibians, reptiles, birds, mammals). The vertebrates and hagfishes together comprise the taxon Craniata.
