1. Animals with a double life
Amphibians
Animals with a double life

2. Primary Characteristic
Amphibians have a completely aquatic larvae which transforms into an air breathing, semi-terrestrial adult.

3. Three orders of Amphibians
Caudata: salamanders & newts
Anura: frogs and toads
Apoda: caecilians

4. Characteristics of Amphibians
Undergo metamorphosis (change)
Thin, moist skin
Four legs
No claws on toes
Three chambered heart
Rely on water for reproduction
Ectothermic

5. Thin, Moist Skin Many amphibians breathe some through their skin
Some salamanders ONLY breathe through their skin
Reptiles have dry, scaly skin

6. Four legs with no claws on toes
Reptiles have claws and sometimes no legs

8. Three-chambered Heart
The amphibian heart is inefficient
Oxygenated and deoxygenated blood gets mixed together in the 3rd chamber

9. Why amphibians breathe through their skin
Because the heart mixes blood, they must take in extra oxygen through their skin
The skin must remain moist for gas exchange

10. Water needed for reproduction
Fertilization usually external
Water needed as medium for transporting sperm

11. Ectotherms Body temp changes with the temp of environment
Regulates body temp through behavior
Become dormant in extreme heat or cold

12. Metamorphosis: Frogs Frog eggs hatch into tadpoles with:
Fins
Gills
two-chambered heart
Tadpoles grow into adults with:
Legs
Lungs
three-chambered heart

14. Metamorphosis: Salamanders
Larvae have:
Gills
tail fin
Adults:
Have no gills
Have no tail fin
Breath through moist skin or lungs.

15. Larvae vs. Adult Spotted Salamander

16. Caudata: Salamanders Long, slender body with a neck and tail.
Look like lizards, but have smooth, moist skin and lack claws.
One fourth breathe through skin and have no lungs.
Most have four legs, but some have only 2 front legs.

17. Newts vs. Salamanders
Newts are salamanders that live entirely in water.

18. Local Salamander Species
Eastern Red Spotted Newt , Slimy salamander, Blue Ridge two-lined salamander

19. The Hellbender
Largest salamander in North America, and one of the largest in the world.
Up to 29 in. long
Live in rivers and large, swift streams

20. Anurans: Frogs No tails Jaws and teeth
Vocal cords capable of producing a range of sound
Use sound to find a mate
Breathe through lungs or skin

22. Frog Songs Vocal cords capable of producing a range of sound
Vocal cords = band of tissues in the throat
Use sound to find a mate
Frogs can be identified by their songs

24. Dart Frogs
Secrete toxic chemicals through skin as a defense against predators.
Some have enough toxins to kill 10 people
Bright colors act as warning coloration

25. Cane Toads Imported to Australia to eat beetles
Toxic to fish and animals
Secretes toxin from glands
Causing reduction in wildlife
Cane Toads

26. The Beauty of Frogs

27. Frog Leaping Frogs can jump over 20 times their own length
That is like a person jumping 100 feet!

28. Breathe through lungs or skin
Frog Respiration
Breathe through lungs or skin

29. Sensitive to Environmental Changes
Are indicator species for pollution in land, air, or water.
Declining numbers or deformities indicate an unhealthy environment.

30. Frogs vs. Toads Frogs: Long, hind legs Smooth, moist skin Toads
Bumpy, dry skin
Short legs

31. Local Species: American Toad
Poison glands in paratoid gland behind ears
Squirts milky poison at predators (like dogs)

32. Local Species: Fowler’s Toad
Common in U.S.
Call sounds like the bleat of a sheep

33. Southern Cricket Frog Dark triangle between the eyes
Call sounds like a series of cricket-like clicks
Tiny – less than 1-1/4 inches long

34. Common Local Frogs Spring Peeper
One of the first songs of the spring
Call is a high-pitched whistle with a trill
Common Local Frogs Spring Peeper

35. Eastern Narrowmouth Toad
Sounds like a bleating sheep
Good at burrowing in soil or leaf litter

36. Bullfrog Largest frog in North America
Eat crayfish, insects, birds, fish
Harvested for legs, which are eaten

37. Green Frog Sounds like the twang of a loose banjo string
Can be green, bronze, or brown

38. Southern Leopard Frog Has a light spot in the center of the eardrum
To escape predators, dives in water, makes a sharp turn, and returns to original shore to hide

39. Apoda: Caecilians No limbs, short or no tail Tropical Look like worms
Small eyes and often blind when eyes are covered by skin
Eat earthworms and other invertebrates in soil

40. What is this?

41. 5. Which is a newt? A B

42. Quiz What does the word, “amphibian” mean?
What are the three classes of amphibians?
How are amphibians different from reptiles?
How are amphibian frog larvae different from the adult frogs?
Where do caelilians live?
Why do many amphibians need to have moist skin?

43. Quiz What is an ectotherm? What kind of salamander
is pictured to the right?
What is the largest salamander in North America?
How are frogs different from toads?
Why are frogs such good indicator species, and what does this mean?

44. Quiz
What kind of amphibian has no legs, often has no eyes, and can be found in tropical environments only?
What is the purpose of the bright skin in a dart frog?
What is the main purpose for a frog song?
What are 3 functions for a cloaca?
What is the function of the tympanic membrane and where is it on the frog?
Where would you find the nictitating membrane?

45. Label the parts

46. 25. Which of the following are amphibians, and how do you know?
A C
B D

47. Name the species:
A B
C D