Amphibians

Vertebrates are… Animals that have a backbone or vertebral column. Animals that have a backbone or vertebral column.

Warm-blooded animals (endotherms)…. Keep their internal body temperatures constant despite changes in the external environment. Keep their internal body temperatures constant despite changes in the external environment. (only birds and mammals are considered warm-blooded animals) (only birds and mammals are considered warm-blooded animals)

Cold-blooded animals (ectotherms)… Keep their internal temperature constant by adjusting their behavior during times of hot and cold weather. Keep their internal temperature constant by adjusting their behavior during times of hot and cold weather. (basking in the sun if they are cold; resting in the shade if they are hot) (basking in the sun if they are cold; resting in the shade if they are hot)

Gills are… Feathery structures through which water-dwelling animals, such as fish, breathe. Feathery structures through which water-dwelling animals, such as fish, breathe.

Amphibians… Are vertebrates Are vertebrates Are fishlike and breathe through gills when young. Are fishlike and breathe through gills when young. Live on land and breathe through lungs and moist skin as adults. Live on land and breathe through lungs and moist skin as adults. Lack scales or claws on their bodies. Lack scales or claws on their bodies.

Amphibians need water… For reproduction. For reproduction. To keep their skin moist for gas exchange (oxygen in, carbon dioxide out) To keep their skin moist for gas exchange (oxygen in, carbon dioxide out) Because they are cold-blooded Because they are cold-blooded

Amphibian reproduction… Reproduction takes place OUTSIDE of the female’s body. This is called External Fertilization. The eggs are released into the water and are then fertilized by the male’s sperm. Reproduction takes place OUTSIDE of the female’s body. This is called External Fertilization. The eggs are released into the water and are then fertilized by the male’s sperm.

Tadpoles versus Frogs… Tadpoles have gills, a tail, and no legs. Tadpoles have gills, a tail, and no legs. Frogs have lungs (and moist skin) to breathe, no tail, and four legs. Frogs have lungs (and moist skin) to breathe, no tail, and four legs. Metamorphosis…tadpoles change into frogs! Metamorphosis…tadpoles change into frogs!

During hibernation… Frogs can conserve energy during periods when food is less abundant. Frogs can conserve energy during periods when food is less abundant.

Frogs versus Toads… Frogs have smooth, moist skin Frogs have smooth, moist skin Toads have bumpy, dry skin Toads have bumpy, dry skin

Frogs are… Cold-blooded because they are unable to move to warmer climates and must hibernate to survive the cold weather. Cold-blooded because they are unable to move to warmer climates and must hibernate to survive the cold weather.