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Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Amphibians Named for the fact that they can live on both land and water amphi = Greek on both sides bian = Greek life 2
Skeleton Clip 1. Legs 2. Lungs 3. Double loop circulation 4. Partially divided heart 5. Cutaneous respiration 3
Some have 4, others 0! Helpful for living on land Tetrapod - vertebrate that has four limbs or is believed to have evolved from limbed ancestors Ex: snakes and caecilians Jumping link 4
Not as efficient as gills O 2 and CO 2 exchange b/w air and blood Air = 20% O 2 Higher than sea water! Large surface area Also breath through skin May use gills at different stages of development 5
2 loops (fish only have 1) 1) Pulmonary = heart/lungs and skin 2) Systemic = heart/body (organs) *Key upgrade : Pulmonary Veins Carry oxygen rich blood from lungs to heart Pumped to tissues at higher pressure More oxygen distribution Found in lungfishes too 6
3 chambered (fish = 2) 2 atria, 1 ventricle Septum - divides atria Prevents complete mixing of oxygen- rich and oxygen-poor blood Oxygen poor stays on side of ventricle that directs to lungs Oxygen rich stays on side of ventricle that directs to body 7
Spiral valve - divides conus arteriosus (leaves heart) Prevents complete mixing of oxygen rich and oxygen poor blood as it leaves heart Not very efficient 8
Oxygen poor blood enters right atria via sinus venosus from body Oxygen rich blood enters left atria via pulmonary veins *Kept from mixing by septum in atria All blood goes to Ventricle (pumping chamber) Pumped thru conus arterious Spiral valve keeps blood from mixing Goes to body if oxygenated Goes to lungs if deoxygenated * Know pathway of blood through heart! 9
Skin Breathing Skin must be kept moist Makes up for heart s inefficiency Limits body size Need high skin surface area to body volume 10
1) Anura (frogs and toads) 2) Urodela (salamanders and newts) 3) Apoda (caecilians) Intro Link Red-eyed Tree frog Marbled Salamander 11
Frogs and Toads Live everywhere except driest deserts and poles Unique behaviors and adaptations (Wood Frog) Some have sticky tongue to catch prey >3000 species of frogs Some frogs and toads have poison (paratoid) glands behind eyes Bullfrogs: Wetland Garbage Disposal 12
Frogs have: Bulging eyes Exposed eardrums Strong, long, webbed hind feet for leaping and swimming Smooth or slimy skin Eggs laid in clusters Toads have: Stubby bodies Short hind legs for walking not hopping Dry, warty skin Eggs laid in long chains Toads are actually a family of frogs Differences clip 13
Wallace s flying frog Can glide up to 50! Female Pygmy Marsupial Frog Tucks eggs into pouch on back West African Goliath Frog Upper body up to 1 long Up to 2 ½ when legs are extended 14
Need water! External fertilization Eggs hatch into tadpoles Eat mostly algae Tadpole becomes adult Carnivores Metamorphosis = process of changing Rate depends on species and food availability Tree Frog Life Cycle 15
Wood Frog egg mass 16
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Salamanders and newts Elongated bodies 4 to 5 Long tails Smooth, moist skin Carnivorous 369 species Tagging Salamanders in WI 18
Lay eggs in water or very moist places Fertilization usually external Female picks up sperm pack and places in cloaca No dramatic metamorphosis Young similar to adults Usually have gills 19
Salamander egg sacs 20
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Caecilians No legs! Tropical Small, bony scales embedded in skin Use hydrostatic skeleton to burrow in soil Eat small invertebrates 4 to 5 long Internal fertilization Female bears live young or lays eggs Live underground; Rarely seen Much not known 22
Biomagnification: a process in which retained substances become more concentrated with each link in the food chain 23
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extra or missing limbs branching limbs spikes or protuberances missing eyes abnormal webbing 25
reproductive digestive urinary link 26
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Dr. David Hoppe, University of Minnesota-Morris 28
Dr. David Hoppe, University of Minnesota-Morris 29
Malformed link Dr. David Hoppe, University of Minnesota-Morris 30
Dr. David Hoppe, University of Minnesota-Morris 31
genetic origins parasite disruption of limb formation chemical contamination viruses ultraviolet radiation physical trauma (predation, people) 32
Dr. Stanley K. Sessions, Hartwick College 33
Dr. Stanley K. Sessions, Hartwick College 34
agrochemicals heavy metals acid rain chlorofluorocarbons (CFCs) 35
The Endocrine system Controls heart rate Metabolism (blood sugar) Sexual development Thyroid Gland Produces Thyroxin hormone Controls development Controls Metamorphosis Frogs have indirect development 36