1. Chapter 15
Section 15:2
Amphibians

2. What is an amphibian?
The word amphibian comes from the Greek word “amphibios” which means “double life’.
Amphibians are ectothermic (body temperature changes with environment) part of their life in the water and part of their life on land. (gills to lungs)
Frog, toads and salamanders.
Moist skin
No scales
Small lung sacs in the chest cavity for breathing.

3. Amphibian Adaptations
Ectothermic cause the amphibian to seek shelter and hide during colder months.
They bury themselves in the mud and leaves until the temperature warms up.
Hibernation – (winter time) the period of inactivity and lower metabolic needs.
Estivation – (summer time) amphibians that live in hot dry environments become inactive and hide in the ground when temperatures become too extreme for them.

4. Skeleton – very strong and made of bone that supports the body on land.
Eggs lack shells so they must be kept moist, most are placed in water where they will hatch into larva.
Larva – tadpoles will live part of their life in the water until they change their body structure and become adults.

5. Frogs Short, broad bodies No neck No tail
Four legs- short hind are longer and strong and are used for swimming, jumping and absorbing the landing impact.
Bulging eyes and nostrils – on top of head so frogs and toads see and breath while they are totally submerged in water.
3 lobed liver
Mesentary – tissue inside that holds organs tightly together.
Cloaca – (anus) where waste, sperm and eggs are released.

6. External body structures
Tongue – long, forked and attached to the front of the lower jaw. It can flip it out much further to catch insects because of the attachment location.
Tympanic membrane – found on each side of the head of an amphibian. The membranes vibrate in response to sounds and are used by the frog to hear.
Nictitating membrane – located inside regular eye lid, third eye lid that can also be closed. Keeps eyes protected from damage while under the water and kept moist.

7. Reproduction Lay eggs in water
Amplexus – Male frogs wraps arms around female and uses his large thumb pads to push and help force eggs out of female.
While eggs are leaving the female the male frog deposits sperm as they enter the water.

10. Toads Use water just for breeding purposes.
Live in woods, fields or gardens.
Thick, warty skin that prevents them from drying out.
Eat invertebrates, spiders, earthworms and caterpillars.
Most have glands on their back that secrete poisons.

12. Salamanders and newts Long, slender bodies. 4 short stubby legs.
Live under leaves and rocks and usually hide during the day to avoid drying out.
Feed on worms, insects.
Breed on land.

14. Japanese Salamander

15. Amphibian metamorphosis
Metamorphosis- a series of changes that a larva goes through to become an adult.
Larva – water
Adult – land
Tadpoles – legless, herbivores, tails and gills.
Adult – 4 legs, carnivores, no tails and lungs.