BIOLOGY 1

Chapter 33

Amphibians

KINGDOM ANIMALIA

SUBKINGDOM EUMETAZOA

PHYLUM CHORDATA

SUBPHYLUM VERTEBRATA

CLASS AMPHIBIA

Class Amphibia

(double life) (ie: newts, frogs, toads)

Common Characteristics:

· ___ chambered heart

· live in water

· adapted to land

· webbed feet

· __________ blooded

· breathe through ________ to help ____________________ lungs

· evolved 345 million years ago

· survived as the top species for 150 million years before another more advanced species evolved

· undergo metamorphosis

· eggs have no shell

(have a leathery membrane around young)

fish ancestor of amphibian - Crossopterygian

Torpor - ______________ in a hostile environment

Hybernation - _______________ torpor

Estavation - ______________ torpor

4 Orders of Class Amphibia

1. Order Anura - amphibians ______________ a tail

(ex. frogs & toads)

n live in deserts to mountains; ponds and puddles

n excellent ___________

n reproduce in water

n all young are called _____________

n toad - rough skin, dry

n frog - smooth skin, damp

n reproduction of Anura

* __________________ fertilization

1.) female lays eggs in a clump

2.) male swims by and deposits sperm over eggs

2. Order Urodela - have legs and tails (ex. Salamanders)

n feel smooth & moist skin

n need to live in ____________ areas

n young are mini adults

n Newt = a fully aquatic urodela

n reproduction of Urodel

* ______________ fertilization

1.) male deposits sperm packet in water

2.) female swims by _____________ packet and places it in her seminal receptacle

3. Order Apoda – ______________ amphibians

(ex. Caecilians)

n live in the tropics in burrows

n eat worms

n __________birth, no eggs

n reproduction of Apoda

* direct contact internal fertilization

** ______________

4. Order Trachystoma - rough mounted & aquatic

(ex. mud eel, sirens)

n have tiny ________________ limbs