The only vertebrates are in phylum Chordata.
The phylum Chordata contains subphylum Vertebrata; vertebrates have a dorsal nerve chord and cartilage or bone. Vertebrates are also bilaterally symmetrical. Most have complex organ systems, two pairs of appendages and reproduce sexually. They all have some form of protective skin and an internal skeleton. Digestive, excretory, circulatory, nervous, and respiratory systems are present and they can be found on land and in the water.
There are 7 main classes of vertebrates, three of which are comprised of fish. Jawless fish, like lampreys, belong to class Agnatha. Cartilaginous fish are in class Chondrichthyes and examples are sharks and rays. Bony fish are in class Osteichthyes. These include tuna, bass, salmon, tilapia, and clownfish. Amphibians (class Amphibia) live in the water and on land. Their skin and eggs must be kept moist, and as adults develop lungs to breathe air. Frogs, salamanders, and toads are all amphibians. Reptiles (class Reptilia) have skin that does not need to be wet and have lungs. Their eggs have a hard shell and thus can be laid on land. Snakes, turtles, lizards, and alligators are all reptiles. Fish, amphibians, and reptiles are also all ectothermic (cold-blooded). Birds (class Aves) also lay eggs with a hard shell. Birds also have wings, feathers, two feet, and are warm-blooded. Not all birds can fly (e.g. penguins). Examples of birds are crows, sparrows, ostriches, eagles, turkeys, and chickens. Finally, mammals (class Mammalia) provide their young with milk from mammary glands. Most mothers carry their young and most have teeth. Like birds, mammals are warm-blooded and instead of feathers, they have hair. There are an estimated 5,000 mammal species, including dogs, bears, okapis, platypuses, whales, buffalo, bats, and humans!
There are 7 main classes of vertebrates, three of which are comprised of fish. Jawless fish, like lampreys, belong to class Agnatha. Cartilaginous fish are in class Chondrichthyes and examples are sharks and rays. Bony fish are in class Osteichthyes. These include tuna, bass, salmon, tilapia, and clownfish. Amphibians (class Amphibia) live in the water and on land. Their skin and eggs must be kept moist, and as adults develop lungs to breathe air. Frogs, salamanders, and toads are all amphibians. Reptiles (class Reptilia) have skin that does not need to be wet and have lungs. Their eggs have a hard shell and thus can be laid on land. Snakes, turtles, lizards, and alligators are all reptiles. Fish, amphibians, and reptiles are also all ectothermic (cold-blooded). Birds (class Aves) also lay eggs with a hard shell. Birds also have wings, feathers, two feet, and are warm-blooded. Not all birds can fly (e.g. penguins). Examples of birds are crows, sparrows, ostriches, eagles, turkeys, and chickens. Finally, mammals (class Mammalia) provide their young with milk from mammary glands. Most mothers carry their young and most have teeth. Like birds, mammals are warm-blooded and instead of feathers, they have hair. There are an estimated 5,000 mammal species, including dogs, bears, okapis, platypuses, whales, buffalo, bats, and humans!