Diversity of Life Part III: Vertebrates

What is a vertebrate Has a backbone that is part of an internal skeleton Formed by bones called vertebrae Joints between vertebrae give flexibility

Fish Vertebrate that lives in the water and uses fins to move Ectothermic (body doesn’t produce internal heat, body temp. changes depending on temp of environment) Obtain oxygen from water through gills (contain blood vessels to transport the oxygen) Closed circulatory system (2 chambered heart) Most have external fertilization

Types of fish Jawless (No jaws and no scales) Skeletons made out of cartilage, a tissue that is more flexible than bone. Examples: Hagfish and Lampreys (attach their mouths to healthy fish and suck the blood and tissues out!) Cartilaginous (have jaws and scales) Skeletons made out of cartilage Examples: Sharks and sting rays Bony fish (has jaws, scales, and skeleton made of hard bone) Contains a swim bladder (gas-filled sac to help fish stay at different depths in the water) 95% of all fish species

Amphibians Vertebrate Ectothermic 3 chambered heart Spends early life in water and adult life on land going back to the water to reproduce. Lose lungs during metamorphosis and use lungs when living on land (organ to exchange oxygen and CO2 between the air and the blood) Examples: Salamanders, frogs Most go through a metamorphosis early in their life changing from a larvae to an adult (tadpolesfrogs)

Reptiles Examples: Lizards, snakes, alligators, dinosaurs Ectothermic vertebrate Has lungs (first organisms to live entirely on land) Scaly skin Lays their eggs on land (not in water) Live entire life on land (so they must conserve the water inside of them!) Use skin, kidneys and eggs to conserve water

Birds Endothermic (body regulates its own temperature by controlling the internal heat it produces) Vertebrate Lays eggs Has feathers 4 chambered heart Adaptations for flight (different types of feathers function for different purposes, hollow bones, large chest muscles) Has crop (organ that stores food)and gizzard (grinds food) for eating. Don’t need teeth!

Mammals Endothermic Vertebrates 4 chambered heart Skin covered with fur or hair Most born alive Every young mammal is fed with milk produced by organs in its mother’s body (mammary glands)

Mammals cont… Have a large muscle called the diaphragm that works with rib muscles to breathe in and out. Many specialized adaptations for movement (swinging on trees, hopping, running) Complex nervous system that coordinates movements. (highly developed senses)