Vertebrates

Characteristics of Vertebrates Vertebrates have a vertebral column and specialized cells that develop from the nerve cord. The vertebral column, or spinal column, is the hallmark feature of vertebrates. Classes of vertebrates include fishes, amphibians, reptiles, birds, and mammals.

Vertebral Column A vertebral column made of cartilage or bone surrounds and protects the dorsal nerve cord. The vertebral column functions as a strong, flexible rod that muscles can pull against during swimming or running.

Neural Crest A neural crest is a group of cells that develop from the nerve cord in vertebrates. Portions of the brain and skull, certain sense organs, and some nerve fibers are some of the structures that develop from the neural crest.

Examples Jawless (eels), cartilagenous (sharks & rays), bony (goldfish, perch) Habitat Water Warm & cold areas Integument (covering) Scales, mucus Respiratory System gills Circulatory System 2 chamber heart Body Temperature Regulation Ectothermic (cold blooded)- absorb heat from surroundings Reproductive Fertilization & Embryo Development External Large # of eggs laid in water Special Adaptations Swim bladder (depth in water) Gills, fins, lateral line Fish

Fish Jawless Fish (lampreys) Bony (goldfish, perch) Cartilagenous (sharks, rays)

Amphibians Examples Frogs, toads, salamanders, legless Habitat Freshwater, close to water, mostly warm areas Integument (covering) Moist skin Respiratory System Moist membranes, gills in larvae, lungs in adult Circulatory System 3 chamber heart Body Temperature Regulation Ectothermic Reproductive Fertilization & Embryo Development External, large # of eggs laid in water, metamorphosis Special Adaptations Lungs, webbed feet, bridge b/w land & water animals Amphibians

Amphibians

Characteristics of Amphibians Thin, moist skin 4 legs (except for the apoda) No claws on their toes Most live on land as adults Require water for reproduction Fertilization is usually external Water is needed to transport sperm so eggs are usually laid in water No protective membranes or shells on their eggs

Differences between a Frog and Toad Generally have smooth, moist skin Longer hind legs (for swimming and leaping) Webbed hind feet Lay eggs in a clump that is a cloudy, jellylike mass Toad Generally have warty, dry skin Shorter hind legs (for walking rather than marathon hopping) More terrestrial Lay eggs in stringy chains

Reptiles Examples Snakes, lizards, turtles, gators/crocs Habitat Landoften dry, mostly warm Integument (covering) Scales, shells Respiratory System Well-developed lungs Circulatory System 3 chamber heart 4 chamber heart (all crocs) Body Temperature Regulation ectothermic Reproductive Fertilization & Embryo Development Internal, amniotic eggs, fewer eggs Special Adaptations Reptiles

Reptiles

Differences between a Amphibians and Reptiles Moist skin Often webbed feet (never clawed) Skin is smooth or bumpy, but must stay wet Ex: frogs, toads, newts, salamanders, and caecilians Reptiles Dry, scaly skin Clawed feet Lungs Ex: alligators, crocodiles, lizards, tortoises, and turtles

Differences between a Crocodile and Alligator Crocodiles Narrow, V-shaped snouts Upper and lower jaws roughly same width Both upper and lower teeth jut out when their mouth is closed 4th lower tooth of each side sticks out prominently Alligators Broad, U-shaped snouts Upper jaw overlaps their lower jaw Upper teeth are visible, lower teeth hidden

Birds Examples Flapping, non-flapping (gliding & soaring) Habitat Land warm & cold areas Integument (covering) feathers Respiratory System Lungs with air sacs Circulatory System 4 chamber heart Body Temperature Regulation Endothermic (warm blooded)- regulate own temperature independent of surroundings Reproductive Fertilization & Embryo Development Internal, amniotic eggs, fewer eggs Special Adaptations Flight with wings & hollow bones, beak, foot adaptations Birds

Birds

Mammals Examples Egg laying, pouched, placental, flying-bat Habitat Land and water warm & cold areas Integument (covering) Skin, hair or fur, scales Respiratory System Lungs and diaphragm Circulatory System 4 chamber heart Body Temperature Regulation Endothermic Reproductive Fertilization & Embryo Development Internal, live birth for placental & pouches, or eggs Special Adaptations Mammary glands, large brain, teeth, nearly all habitats Mammals

Mammals