AMPHIBIANS Amphibian means “double life”

CLASSIFICATION  Eukaryote Domain Animal Kingdom  Phylum Chordata (vertebrates)  CLASS: FISH, AMPHIBIANS, REPTILES, MAMMALS, BIRDS

Life on water and land  Larvae live in water (aquatic) Respiration with gills and skin  Adults live on land (terrestrial) Respiration with lungs and skin

I. Characteristics 1. Vertebrate (backbone) 2. Lives in water and on land 3. Moist skin 4. Lack scales and claws 5. Ectothermic (cold – blooded)

II. Evolution  Evolved in the swampy tropical ecosystems of the Devonian Period (1 360mya).  Next: The “Age of Amphibians” was the Carboniferous Period (360 to 290 mya). Many species appeared and ruled the land!

Amphibian Groups  Frogs and Toads Order Urodela – they jump  Salamanders Order Anura – long bodies  Caecilians Order Apoda – legless, long bodies

III. The Amphibian Body: A. Respiratory system tadpole - gills and skin adults – lungs and skin B. Circulatory system 1. double loop: body to heart, lungs to heart 2. 3 chambered heart 2 atria, 1 ventricle

C. Feeding FROGS and TOADS  Herbivores as tadpoles  Carnivores as adults Eat anything they can catch! SALAMANDERS  carnivores

Digestive system  Mouth  Pharynx  Esophagus  Stomach  Small intestine* * liver and pancreas produce digestive juices  Large intestine (colon)  Cloaca –One opening for the removal of waste, urine, eggs and sperm.

REPRODUCTION  Courtship dances (salamanders)  Courtship calls (frogs/toads) Male and female find each other with frog songs. Each species has identifying “songs”  External fertilization  Egg layers – eggs must be laid in water/or moist environment

Egg Incubation/Parent Behavior  Most species abandon eggs (frogs 200)  Some species take great care of eggs and young.  Some species carry incubating eggs on their back, in their mouth, in their stomach Ex. male midwife toad

Adaptations for Movement EXAMPLES Frogs and toads - large hind legs for jumping - suction cups on feet salamanders - body takes S shape and springs forward