The Vertebrates: Phylum Chordata

Major Classes of Vertebrates Above: Class Amphibia: Includes all amphibians (frogs, toads, salamanders) Below: Class Aves: Includes all birds Above: Class Sauropsida: Includes the reptiles Below: Class Mammalia: Includes all mammals

Class Chondrichthyes: Includes all cartilaginous fish ex. shark Class Osteichthyes: Includes all bony fish

Characteristics of All Vertebrates Coelomate and bilaterally symmetrical which allows for complex body systems Have backbones with a protected spinal column and endoskeleton Advanced central nervous system with large brain with skull Have unequivocal head, eyes and sensory organs Complex heart and circulatory systems Muscular system consists of mostly paired masses Possess a special outer covering Have 1 or 2 pairs of appendages Are found on land and water

Adaptations of Vertebrates Class Amphibia Have gills and very primitive lungs to exchange gasses as they live half of their life in water and half on land Can also take in gasses through their moist skin Lay eggs in the water after sexual reproduction which develop into tadpoles

Adaptations of Vertebrates Class Aves : The Birds Adaptations for Flight Feathers 4 chambered heart Hollow bones for strength without weight Large sternum for wings to attach and put pressure Lungs and air sacs are used to improve gas exchange at thin altitudes

Bony Fishes Skeleton is made up of bone Have a swim bladder to regulate buoyancy Perform external fertilization and lay eggs Have been very successful because they can reproduce in large quantities Cartilaginous Fishes Skeleton is made up of cartilage Do not have a swim bladders Perform internal fertilization and bear live young What’s the Difference?

Endotherms Warm blooded Body temperature remains constant regardless of external temperature changes Endotherms can regulate their metabolic rate and are more independent of their environments Ectotherms Cold blooded Body temperature varies with the surrounding environment Cannot regulate their metabolic rate very well What’s the Difference?

Characteristics of Mammals Warm blooded Air breathing 4 legged vertebrates Possess skin with hair and sweat glands Have teeth with a jawbone Fleshy lips Diaphragm 4 chambered heart Have a brain and middle ear Bear live young Have mammary glands

Ecological Roles of Vertebrates All are part of the food chain Amphibians contribute to wetland ecology, prey on insects and devour algae and dead plants Reptiles are predators of pests Birds control insect and vermin populations as well as act as pollinators Mammals aerate soil and are sensitive to environmental changes