Vertebrates: animals with a backbone
ECTOTHERMIC
FISH
REPTILES
ENDOTHERMIC
— live in water; uses fins to move; most are ectothermic; breathe through gills and have scales; fish are the biggest group of vertebrates.
2 chambered heart #
There are three types of fish, bony ones, jawless ones and cartilaginous ones. Bony fish have jaws, scales, and a pocket on each side of their heads holding the gills. Their skeletons are made of hard bone.
AMPHIBIANS
— amphibian means " double life" because they live fist in water, and then, during adulthood, migrate to land; they reproduce and lay eggs in water; they have 3-chambered hearts.
— reptiles have scaly skin; they lay eggs on land; some, live in water but still breathe air; most reptiles live on land; their skin is thick; they have kidneys that store water; most younglings develop inside tough shelled eggs.
MAMMALS
— mammals are covered with fur or hair; they young are fed by the mother's mammary glands; mammal groups differ by how how their young are developed; there are three types of mammals.
BIRDS
— birds lay eggs; they have feathers, wings, and lightweight, nearly hollow bones; birds are the only modern animals with feathers
Monotremes lay eggs.
Marsupials are born at an early stage of development and continue to develop in their mother's pouches.
Placental mammals develop inside their mother's body until their bodies can function independently.
Lastly, cartilaginous fish have jaws, scales, and skeletons made of cartilage
Jawless fish have no jaws or scales, they scrape, suck, and stab their food. .