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Amphibian Phylogeny
Lungfish
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First discovered 1830
Lungs similar to land animals
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Modified swim bladder
They are closest relative of tetrapods (4 legs)
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Tooth enamel
Similar skull bone structure
Pulmonary and systemic circuit of blood flow
Four similar sized limbs
Lungfish
Coelacanth
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http://www.pbs.org/wgbh/nova/nature/an
atomy-coelacanth.html
Type of lobed-finned fish
Origins of Amphibians
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Metamorphosis
Apoda: Worm like
Urodela: Newt/Salamander
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Michigan Species
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Blue-spotted Salamander
Eastern Newt
Eastern tiger salamander
Four-toed salamander
Marbled salamander
Mudpuppy
Red-backed salamander
Small mouthed salamander
Western lesser siren
Examples of Michigan Urodela
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Blue-spotted
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Marbled
Eastern Newt 4-toed
Anura
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Michigan Species
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Blanchard’s cricket frog
Bullfrog
Eastern American toad
Fowler’s Toad
Grey tree frog
Green frog
Mink frog
N. leopard frog
N. spring peeper
Pickerel frog
W. chorus frog
Wood Frog
Michigan species
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Bullfrog
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Wood
greenfrog leopard
Spring peeper
Pickerel
Salamanders
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Tailed amphibian
American Hellbender
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Must live in moist
areas
Secrete mucus
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Maintain moisture
Balance salt levels
Protection
Salamanders vs. Lizards:
Skin
Salamanders
Similar to Ours
Claws
No
Postur
e
Body low to the
ground
Life
Cycle
Start as Larvae
Lizards
Covered in
Scales
Yes
Body held
higher above
the ground
Start as smaller
adults
General Anatomy
Salamander Respiration
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Types of Respiration:
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External gills
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Lungs
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Mudpuppy
Single simple lung
Very inefficient
Skin (cutaneous respiration), all salamanders
can do this
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Why they must remain moist
Aquatic Habitat
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Larvae are born in water using external gills
Juveniles and Adults breathe through external gills if
retained, skin if not
Breathing through skin requires constant moisture, easy
if aquatic
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EX: Mudpuppy
Environmental Issues
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Salamanders, like all amphibians are one of the first
organisms to be affected by environmental changes due
to their soft-shelled eggs and respiring skin.
Aquatic eggs are jelly-like and can be affected by UV and
chemicals in the water.
All salamanders can breathe through their skin so any
chemicals that come in contact with them easily pass
into their bodies.
Moisture is critical to all salamanders.
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Deforestation leads to areas with less moisture, effectively
destroying terrestrial salamander habitat
Anura (Frog/Toad)
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Live everywhere (except Antarctica)
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Most species in tropics
Ectotherms
Evolved capabilities to live in all biomes
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Desert, mountain, tropics, freshwater systems
Toads
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Rough, dry skin
Very terrestrial
Use soil to maintain body moisture
Need water source for larva stage
(tadpole)
Toads
Frogs
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Smaller body structure than toad
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More angular than toad body
More reliant on water than toads
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Moist skin
Secrete mucus
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Similar to function in salamanders
General Frog/Toad Anatomy
Anterior Anatomy
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Key Features
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Nicitating membrane
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Tympanic membrane
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External eardrum
Eustachian Tubes
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3rd eyelid
Balance pressure
Teeth
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2 vomerine teeth:
Maxillary teeth: hold prey
Anterior Anatomy
Skeletal System
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Similar to mammalian skeleton
Functions as system of levers
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Muscle attachment
Digestive
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Very similar to other vertebrates
Digestive Tract: What nutrients pass through
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Mouth  Esophogus  Stomach  Small Intestine
(duodenum, ileum)  Large Intestine/Colon 
Cloaca  Vent
Accessory Organs: Provide enzymes
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Liver/gall bladder
Gastric gland
Pancreas
Excretory System
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Use skin to excrete some waste
(respiratory waste)
Cloaca collects digestive waste
Kidney major excretory organ
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Urinary system
http://www.stowe.k12.vt.us/sms/teachers/jgrogan/images/frogcircexcrete.jpg
Circulatory System
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Pulmonary and systemic circulation
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Atrium(s)
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Pulmonary: Heart  Lung  Heart
Systemic: Heart  Body  Heart
Left: collects blood from lung, sends to the ventricle
Right: Collects blood from body, sends to ventricle
Ventricle
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Pumps blood to both lungs and body
Major Vessels
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Conus arteriosus: Heart  systemic or
pulmonary circ.
Pulmonary vein: Lung  Heart (LA)
Pulmonary artery: Conus arteriosus 
lung
Sinus Venosus: Body  Heart
Problems w/ 3 chambered Heart
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Not as efficient as a 4 chambered
(mammalian heart)
Oxygenated and deoxygenated blood mix
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Lungs get some blood that is already
oxygenated
Body gets some blood that is already
deoxygenated
Respiration
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Use both lung and skin to exchange gases
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Skin = pulmocutaneous circulation
4 options for respiration
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May use one or more
Lungs (adult)
Skin (adult)
Mouth (adult)
Gill (larva, some adults-mudpuppy)
Nervous
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Similar to that of a
fish
Reproductive
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Do not have amniotic egg
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No water barrier  must keep moist
Most use external fertilization
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Male fertilizes eggs as female lays them