By: Anthony Rongione and Hunter Haines

1. Amphibians By: Anthony Rongione and Hunter Haines

2. General Information • There are over 6,000 species of Amphibians. • Most live in the water and land. • Are ectothermic. • Lay eggs in water. • Includes toads, frogs, salamanders, newts, and caecilians. • Undergo a metamorphosis from a juvenile form that presides in water, and an adult form. • Have moist skin to help prevent dehydration and respiration.

3. Structural Features • Posses 4 limbs (except caecilians). • Have sticky tongues to capture food. • Majority of adult amphibians have teeth. They are not used for chewing but for holding prey.

4. Locomotion • As a tadpole or pollywog, amphibians use a tail to allow them to swim. • Most adult amphibians have 4 legs which can be used for terrestrial or aquatic locomotion. • In frogs and toads, back legs are typically longer to assist in jumping.

5. Feeding/Digestion • Amphibians are carnivorous and feed on earthworms, insects, arthropods, and small vertebrates. • Aquatic amphibians lunge and suck food into their mouths, while terrestrial amphibians have a sticky projectile tongue that captures prey. • Amphibians have the same type of digestive system as humans except all waste is excreted through the cloaca.

6. Respiration • Have skin that is permeable to water, oxygen, and carbon dioxide. • Most amphibians have lungs but lack the muscles and diaphragm. Instead air is forced into the lungs from the compressing of the mouth floor. • Some amphibians have no lungs and use their skin to breathe.

7. Circulation • Amphibians have a three chamber heart. • Amphibians are cold blooded which allows them to change their body temperature depending on the environment.

8. Nervous System • Amphibians have a nervous system very similar to that of a human. • In contrast they have ten cranial nerves, whereas other animals have twelve. • Amphibians do not have ear and their eardrums are exposed.

9. Reproduction • Amphibians go through a three stage life cycle (egg, larvae, adult). • Amphibian eggs are placed in the water where the larvae form of the amphibian will grow. • As a larvae, or tadpole, amphibians have gills and a tail to help them move and survive in the water. • At the end of the larvae state, tadpoles go under a metamorphosis where their tail shrinks and four limbs begin to form.