Amphibians

Chapter 3 Section 3

Vocab Words

• Amphibios• Hibernation• Estivation• Metamorphosis• Anura

• Caudata• Apoda• Tympanic Membrane• Biological Indicators

Amphibians

• Amphibios– Greek– Means “double life”

• Most primitive group of land chordates

• Classification– Kingdom: Animalia– Phylum: Chordata– Class: Amphibia

Amphibian Characteristics• Ectotherms

– Hibernation• Period of inactivity during cold winter months• Amphibians bury themselves in the mud until the

weather gets warmer

– Estivation• Inactivity during weather that is too warm

• Respiration– Have moist, smooth, thin, scale-less skin– Can breathe through their skin and lining of

their mouths– Most have small saclike lungs in the chest

cavity

• Circulation– 3 chambered heart

• Limited mixing of O2 and CO2 blood

Right AtriumLeft Atrium

Ventricle

• Reproduction– Dependant on water– Jelly-like eggs that do not have a protective

waterproof shell– External fertilization

• Development– Most amphibians go through metamorphosis,

a change in their appearance from hatchling to adult.

• Meta means “change”• Morph means “shape”

AMPLEXUS

http://images.google.com/imgres?imgurl=http://wdfw.wa.gov/wlm/living/graphics/frog2.jpg&imgrefurl=http://wdfw.wa.gov/wlm/living/frogs.htm&h=502&w=550&sz=24&hl=en&start=60&tbnid=yCEOOdzi-ATj_M:&tbnh=121&tbnw=133&prev=/images%3Fq%3Damphibian%2Bhibernation%26start%3D54%26gbv%3D2%26ndsp%3D18%26svnum%3D10%26hl%3Den%26safe%3Dactive%26sa%3DN

Orders of Amphibians

1. Anura: Frogs and Toads

2. Caudata: Newts and Salamanders

3. Apoda: Caecilians and Sirens

Anura: Frogs and Toads

• Short, broad bodies with 4 legs

• No neck or tail

• Tympanic membranes for hearing

• Tongues are attached to the front of their mouths to flip out and catch prey

What’s the difference between frogs and toads?

Frogs:• More aquatic (water based)• Bulging eyes• Long hind legs for leaping• Smooth, slimy skin• Have teeth in the upper jaw

Toads:• More terrestrial (land based)• Poison glands behind the eyes• Short hind legs for walking• Bumpy, dry skin• No teeth

Don’t be Scared!

• Batrachophobia- Fear of amphibians

• Ranidaphobia- Fear of frogs

• Bufonophobia- Fear of toads

Don’t buy into the Frog and Toad Prejudice!

• The “tickle” you feel in your throat is actually caused by the draining of your sinuses – not a trapped amphibian!

• Toads do NOT cause warts– Warts are caused by a virus that is only

transmitted to and from humans!– Toads have brown bumpy (wart-free) skin to

help them blend into their habitat (camouflage)

Green is good!

Caudata: Newts and Salamanders

• Have slender bodies, short legs, and long tails

• Capable of re-growing lost limbs

• Ability to quickly switch from walking to swimming

What’s the difference between newts and salamanders?

Newts:– More terrestrial (land based)– Smooth sides

Salamanders:– More aquatic (water based)– Have costal grooves

Apoda: Caecilians and Sirens

• Eel like tailless amphibians

• Nearly functionless eyes

• No external ear openings

• The body is arranged in rings, called annuli, which gives them an earthworm like appearance

• Unlike all other amphibians, they have scales under their skin.

What’s the difference between a caecilian and a siren?

• Caecilians:– More terrestrial (land based)– Lungs– Dozens of needle sharp teeth

• Sirens:– More aquatic (water based)– Two small forelimbs – Gills and lungs– Few small teeth

Importance of Amphibians• Keep insect populations in check• Provide food for humans and other

animals• Toxins

– Used by native people for hunting– Researched to find out how the nervous

system works

• Regeneration– Studies are being conducted to find ways of

treating humans who have lost/were born without limbs

• Biological indicators: a species whose overall health reflects the health of a particular ecosystem– Why Amphibians?

• Live on land

• Reproduce in water

• Absorb gases through their skin

They are directly affected by any chemical change in the environment

Biological Indicators

Scientists found that an excess of nitrogen and phosphorous from

fertilizers caused this deformation in local frogs

Origin of Amphibians

• Thought to have evolved from lobe-finned fish 350 mya

• First appeared in the Carboniferous Period

• Permian Period is known as the “Age of Amphibians” – 280-248 mya

I’m Ichthyostega and I’m one of the first amphibians although I still had a few fish-like features like my tail.

Amphibians in Review