Animal Lab Final exam- Amphibians

Clade Tetrapoda

have fours legs

3-chambered heart

Tiktaalik

missing link between ancestral Sarcoptrygii and modern tetrapods

limbs could support body weight

can move neck independently of their body

Clade Amphibia

frogs, salamanders, and caecillans

transition between aquatic and terrestrial habitats

require moist environment for external fert and dehydration

semipermeable skin - can breathe through

What are some Amphibian adaptions for life on land

two pairs of appendages - shoulder and hip girdles for support

ectothermy

lungs for respiration

3- chambered hearts

external gills

can have external or internal fertilization

positive pressure breathing

What type of fertilization do different organisms in amphibia

frogs - external

salamanders - internal

caecilians - internal or external

countershading

dorsal side is darker in color and ventral side is lighter

what kind of breathing do amphibians use

positive pressure - draw in air through nostrils by expanding buccal cavity then it closes

swallowing air

What are the advantages of amphibian skin

easy to hydrate

can absorb oxygen in water

secrete poisons

What are the disadvantages of amphibian skin

prone to dessication on land

skin diseases can inhibit respiration

What does the amphibian circulatory system entail

a three-chambered heart - 2 atria and 1 ventricle

partial separation of oxygenated and deoxygenated blood

its a double circuit system - consists of pulmonary and systemic circuits

ectothermy

organism relies on external environment heat sources to regulate its body temperature

may lay in sun or mud

Whats the amphibian life cycle

have jelly-like eggs that hatch to aquatic larvae into terrestrial adults

urostyle

shock absorbing pelvis, prevents injury when jumping

frog skeletal adaptations

urostyle

long hind limbs to push forward

first tetrapods - have 2 pairs of appendages

cloaca

defecation, urination, release of gametes

tympanum

membrane posterior to eye that detects sound

liver

3 lobes

detoxicify blood and produces bile

Gallbladder

store bile

stomach

chemical and mechanical digestion

pancreas

secretes digestive enzymes

intestine

nutrient absorbtion

tongue

capturing prey

fat bodies

fat (energy) storage