AMPHIBIANS
Amphibian means “double life”
CLASSIFICATIONEukaryote Domain
Animal KingdomPhylum Chordata (vertebrates)
CLASS:
FISH, AMPHIBIANS,
REPTILES, MAMMALS, BIRDS
Life on water and landLarvae live in water (aquatic)
Respiration with gills and skinAdults live on land (terrestrial)
Respiration with lungs and skin
I. Characteristics1. Vertebrate (backbone)2. Lives in water and on land3. Moist skin4. Lack scales and claws5. Ectothermic (cold – blooded)
II. Evolution Evolved in the swampy tropical
ecosystems of the Devonian Period (1st @ 360mya).
Next: The “Age of Amphibians” was the Carboniferous Period (360 to 290 mya). Many species appeared and ruled the land!
Amphibian GroupsFrogs and Toads
Order Urodela – they jumpSalamanders
Order Anura – long bodiesCaecilians
Order Apoda – legless, long bodies
III. The Amphibian Body:
A. Respiratory system tadpole - gills and skinadults – lungs and skin
B. Circulatory system1. double loop:
body to heart, lungs to heart2. 3 chambered heart
2 atria, 1 ventricle
C. FeedingFROGS 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.
REPRODUCTIONCourtship dances (salamanders)Courtship calls (frogs/toads)
Male and female find each other with frog songs.
Each species has identifying “songs”
External fertilizationEgg layers –
eggs must be laid in water/or moist environment
Egg Incubation/Parent Behavior
Most species abandon eggs (frogs lay @ 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 MovementEXAMPLES
Frogs and toads- large hind legs for jumping
- suction cups on feet
salamanders- body takes S shape
and springs forward