AMPHIBIANS

1
AMPHIBIANS

• DOUBLE LIFE ORGANISMS

2
AMPHIBIANS

• Examples frogs, toads, salamanders, caecilians
• Habitat aquatic, terrestrial
• Undergo metamorphosis
• Integument moist skin, exception toad
• Appendages tadpole tail fin
• adult 4 legs w/ toes,
  maybe
• webbing increased
  muscle
• complexity

3
AMPHIBIANS

• Bony endoskeleton w/ cartilage
• Jaws w/ small teeth
• Diet young herbivores, adults carnivores
  avoid food competition
• More coiling of gut
• Cloaca present
• Gill, lungs, skin for respiration

4
AMPHIBIANS

• Closed circulation w/ 2 heart chambers in young,
  3 in adult, single loop changes to double loop
• Ectothermic body temp
• Hibernate
• Estivate
• Kidneys, urea and uric acid, water conserved,
• cloaca

5
AMPHIBIANS

• Brain w/ dorsal nerve cord
• 5 senses, tympanum is an advancement
• Separate sexes w/ external fertilization,
• cloaca

6
AMPIBIAN METAMORPHOSIS

• Allows transition from water to land
• Leg-less gt legs
• Tail gt tail-less
• Gills gt lungs
• 2 heart chambers gt 3 heart chambers
• Single loop gt double loop
• Herbivores gt carnivores

7
AMPHIBIANS

• Evolutionary line of thinking
• Amphibians evolved from lungfish