Amphibians

1. Amphibians The word amphibian comes fro the Greek word amphibious- meaning double life

2. Lifestyle • spend part of their life on land • part of their life spent in water • ectotherms • hibernate • estivate

3. appearance • smooth, moist skin • no scales • thin skinned for oxygen exchange

4. heart • three chambered heart • one chamber receives oxygen filled blood • one chamber receives carbon dioxide filled blood • the third chamber pumps oxygen to body tissues and carbon dioxide back to the lungs

5. Reproduction • depend on water for reproduction • their eggs dry out easily • external fertilization

6. Development • metamorphosis • fertilized eggs become a tadpole • tadpoles grow into the adult frog with legs, 3 chambered hear and lungs • In salamanders the young look just like the adults

7. Biological Indicators • Easily affected by changes in the environment • they absorb things directly through their skin making them susceptible to pollutants • Their eggs are exposed in the water and can be easily affected by pesticides