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 O 2 and CO 2 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

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” – 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