The Vertebrates: Phylum Chordatawww.onacd.ca
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 VertebratesClass 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 VertebratesClass 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