AmphibiansAmphibians

AmphibiansAmphibians

VertebrateVertebrate (backbone) (backbone) EctothermicEctothermic (cold- (cold-

blooded)blooded) Must absorb heat from Must absorb heat from

externalexternal sources sources When environment When environment

becomes too hot or too becomes too hot or too cold, many amphibians cold, many amphibians become become dormant dormant (inactive (inactive or at rest) by burrowing in or at rest) by burrowing in the the mudmud..

Amphibians: MetamorphosisAmphibians: Metamorphosis

All amphibians begin life in All amphibians begin life in waterwater Most amphibian eggs are fertilized Most amphibian eggs are fertilized externallyexternally Eggs do not have Eggs do not have shellsshells (moist; must lay in water) (moist; must lay in water)

Amphibians: MetamorphosisAmphibians: Metamorphosis

Fertilized eggs hatched Fertilized eggs hatched into into tadpolestadpoles (larval (larval stage)stage) Tadpoles have Tadpoles have finsfins, , gillsgills, ,

and a and a 22-chambered heart-chambered heart

Tadpoles develop into Tadpoles develop into adultsadults Develop Develop legslegs, , lungslungs, and a , and a

33-chambered heart-chambered heart

Amphibians: RespirationAmphibians: Respiration

Tadpoles obtain Tadpoles obtain oxygen from oxygen from waterwater that passes over gillsthat passes over gills

Adults have lungs so Adults have lungs so that they can that they can exchange gases with exchange gases with the airthe air

Adults also exchange Adults also exchange gases through their gases through their thin, moist thin, moist skinskin

Salamander tadpole with feathery gills extended

Amphibians: CirculationAmphibians: Circulation

Tadpole – 2-Tadpole – 2-chambered heart and chambered heart and a a single loopsingle loop of of vesselsvessels

Adult – 3-chambered Adult – 3-chambered heart and heart and two loopstwo loops of vessels (needed of vessels (needed for life on land)for life on land)

Types of Amphibians:Types of Amphibians:

Order Anura – Order Anura – frogs & toadsfrogs & toads Do not have Do not have tailstails; feed on insects and worms; have ; feed on insects and worms; have

jaws and teeth; frogs have jaws and teeth; frogs have long long legs and legs and smoothsmooth skin; toads have skin; toads have bumpybumpy skin and skin and shortshort legs legs

Types of Amphibians:Types of Amphibians:

Order Caudata – Order Caudata – salamanderssalamanders Long, slender body with Long, slender body with neckneck and and tailtail; smooth, moist ; smooth, moist

skin and no skin and no clawsclaws; some live in water, others in ; some live in water, others in damp places; hatch from eggs, adults are damp places; hatch from eggs, adults are carnivorouscarnivorous

Types of AmphibiansTypes of Amphibians

Order Gymnophiona – caeciliansOrder Gymnophiona – caecilians BurrowBurrow into the ground; no into the ground; no limbslimbs; short or no tail; ; short or no tail;

live in warm, live in warm, tropicaltropical climates; usually climates; usually blindblind; eat ; eat earthworms; earthworms; internalinternal fertilization fertilization

                                                                                                            

Comparison of HeartsComparison of Hearts