In addition to five classes of fish, what other classes make up the species of vertebrates?
insects, amphibians, reptiles, and birds
amphibians , vertebrae , birds , and mammals
reptiles, birds, mammals, and primates
amphibians, reptiles, birds, and mammals
There are about 50,000 living species of vertebrates. They are placed in nine classes: five classes of fish plus amphibians, reptiles, birds, and mammals.