1. Amphibians Chapter 17C 1

2. Characteristics of Amphibians Life Cycle: Body: Typically have a two-part life cycle. – Swimming stage with gills – Terrestrial stage with lungs Most have moist skin (no scales) Most have webbed feet with claws Endothermic May breathe through lungs or skin (including lining of mouth!) Amphibians have 2 part life cycle in the water and on land. They have moist skin, are endothermic and may breathe through mouth/skin or with lungs. 2

3. Metamorphosis Habitat Changes: Feeding: Respiration: From aquatic (swimming and breathing with gills) to terrestrial (breathing with lungs) Tadpoles are herbivores Adults are carnivorous Tadpoles breathe in the water with gills Adults breathe with lungs 3 Metamorphosis is the process whereby amphibians change from aquatic tadpoles breathing with gills to terrestrial animals breathing with lungs. They go from being herbivores to being carnivores.

4. Circulation How do frogs differ from fish? Frogs 3 chambered heart! – Fish 2 chambers Frogs have lungs! – Fish no lungs only gills. 4 Frog differ from fish in respiration in that they have a 3 chambered heart and use lungs as adults.

5. Digestive System of Amphibians Path of food: Mouth Short esophagus Stomach Pyloris (Muscle that controls movement of food from stomach to intesine.) Small Intestine Cloaca (Similar to our large intestine.) 5 The food in an amphibian moves from the mouth to the anus much the same as it does in a human!

6. Respiration in the Frog 4 possible means of respiration available to frogs: Of interesting note: 1.Skin 2.Mouth Lining – called buccal respiration 3.Lungs 4.Gills (In larval/tadpole stage) Frogs have no ribs or diaphragm to draw air into lungs. They draw in air by lowering the floor of their mouths! 6 Frogs have 4 means by which they can take in oxygen! Through their skin, mouths, lungs and gills!

7. Frog Reproduction Structures of Frog Reproduction: Note: Frog fertilization if external! Female: – Large ovaries full of eggs! – Ovaries burst and fill body cavity with eggs. – Eggs are then stored in uterus until laid. Male: – Have sperm producing testes. – Sperm is put on eggs after eggs are laid. 7 Frogs reproduce externally after the female frog lays the eggs!