AMPHIBIANS

Ms. Bridgeland 5th Grade

Objectives and Questions:

• Objective: Describe amphibian characteristics and examine how adult amphibians are adapted for life on land.

• Question: What are the main characteristics of amphibians?

Amphibian: “Double – life?” They begin their lives in water

and spend their adulthood on land

To reproduce, they return to water

2 Major Groups of Amphibians1) Salamanders

:

2) Frogs/Toads:

How can you tell the difference between salamanders and frogs/toads?

Salamanders have a tail even when they are adults

Frog/toads lose their tails before they become adults

“What are the differences between FROGS and TOADS?”

Frogs Toads

FROGS: Need to live near water Have 2 bulging eyes Strong, long, webbed hind feet that are

adapted for leaping and swimming Strong and slimy skin (like very moist

environments) Will take long jumps Like to lay eggs in clusters Found on every continent except Antarctica More than 400 species Have a lot of PREDATORS

TOADS Can live further away from water Lower, football-shaped eyes Stubby bodies with short hind legs (for walking

instead of hopping) Warty and drier skin Lay eggs in long chains Will run or take small hops Can be found worldwide except for Madagascar, the

polar regions, and Polynesia More than 300 species Do NOT have a lot of predators

Amphibian Reproduction Salamanders – eggs are fertilized

internally Frogs and toads –eggs are fertilized

externally For all amphibians, Fertilized eggs

develop in water What is special about amphibian eggs is

that they have a protective jelly that coats the egg

Stage 1: Adult frogs lay eggs in water

Stage 2: Fertilized Eggs Fertilized eggs are laid in water for a few

days

How are Amphibian Eggs different from other eggs?

Stage 3: Larvae After a few days, larvae wriggle out of a

jelly that coats the egg and begin a free-swimming, fishlike life

larvae of a frog or toad is called a _________

As they grow, larvae undergo a ______________________?

Metamorphosis A process where an animal develops after birth

or hatching, involving a sudden change in the animal’s structure

Stage 4: Larvae develops hind legs

Stage 5: Front legs develop but frog still has tail

Stage 6: Frog loses tail and becomes a mature adult

Amphibians: ADAPTATIONS

What is an adaptation? Once amphibians are adults, what new adaptations do they need to live on land?

Adaptation 1: OXYGEN While amphibians are larvae,

(exampletadpoles), how do they breathe?

Once, they are on land, how do they breathe? Amphibians must get oxygen from the

AIR instead of the water once they are on land

During metamorphoses, amphibians lose their gills and develop LUNGS.

What two gases are exchanged through the lungs? OXYGEN and CARBON DIOXIDE