To body by Hs49uGw

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									“having two lives” – land
and water
General characteristics
    • smooth, moist skin
    • 3 chambered heart
    • external fertilization
    • cold blooded - ectothermic
    • respire with gills ( young ),
       lung and/or skin in adults
• eggs must be laid in moist
     environment
• eggs are jelly-like.
amplexus - male clasps female and
sheds sperm onto her eggs
Fish – 2 chambered heart
 1 atrium and 1 ventricle


• a low pressure system
• one continuous loop
From body
            atrium


                     ventricle




                                 To lung

FISH HEART
Amphibians -
 3 chambered heart
 with 2 circulatory loops

• pulmonary loop
    ( heart – lung – heart )

• systemic loop- delivers O2
  ( heart – body – heart )
    From lung
                  AMPHIBIAN HEART

                     atrium

From
  body                  ventricle


                                    To lung


         atrium

                       To body
from lung

                              to lung



from
body                    Blood to body is
                        pressurized

            organs, muscles
Amphibians evolved 350 mya in

The Devonian period from

lobe finned fish like the

 Coelocanth
Lobe finned Coelocanth
Icthyostega – ancient amphibian
There are 3 orders of amphibians

• Anura - frogs and toads

• Caudata – salamanders

• Caecilians - legless
caecilians
Cooked frog legs

								
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