Class Amphibia

1
Class Amphibia

• The Tetrapods

2
(No Transcript)
3
(No Transcript)
4
Moving Ashore
5
Transitional Forms
6
Early Land Tetrapods
7
Evolutionary Lung Forms
8
Changes in Lung Anatomy In Tetrapods
9
Amphibian Respiration
10
Changes in Vertebrate Circulatory Systems
11
Amphibian Heart Anatomy
12
General Amphibian Traits

• Tetrapods
• 3-5 digits on forelimb (most 4)
• 5 digits on hind limb
• No dermal scales
• Glandular epidermis
• Most with indirect development, some with tadpole
  larvae
• Gills as larvae/juveniles, lungs present but may
  degenerate, some with dermal respiration

13
Order Gymnophiona

• 160 species
• Legless
• Burrowing or aquatic
• Tropical
• Internal fertilization
• Oviparous viviparous species
• Direct development in most

14
Order Gymnophiona (Apoda)
Caecilians
15
Order Caudata (Urodela)

• AKA Salamanders
• Have a tail
• Divergence in respiratory mechanisms
• Paedomorphosis prevalent
• Internal fertilization

16
Salamander/Newt Lifecycle
17
Some Urodeles
18
Order Anura

• Frogs Toads
• No tail
• External fertilization
• Indirect development in most

19
Frog or Toad?

• Frogs
• Associated with more aquatic habitats
• Toads
• Thicker skins
• Dryer habitats

20
Her Royal Highness

• Xenopus laevis
• Developmental model system

21
Typical Anuran Lifecycle
22
Really Weird Surinam Toad
23
(No Transcript)
24
Local Species
Acris crepitans
Rana catesbeiana
Bufo speciosus
Bufo woodhousii
Pseudacris clarki
Rana pipiens