AMPHIBIANS

Amphibian means “double life”

CLASSIFICATIONEukaryote Domain

Animal KingdomPhylum Chordata (vertebrates)

CLASS:

FISH, AMPHIBIANS,

REPTILES, MAMMALS, BIRDS

Life on water and landLarvae live in water (aquatic)

Respiration with gills and skinAdults live on land (terrestrial)

Respiration with lungs and skin

I. Characteristics1. Vertebrate (backbone)2. Lives in water and on land3. Moist skin4. Lack scales and claws5. Ectothermic (cold – blooded)

II. Evolution Evolved in the swampy tropical

ecosystems of the Devonian Period (1st @ 360mya).

Next: The “Age of Amphibians” was the Carboniferous Period (360 to 290 mya). Many species appeared and ruled the land!

Amphibian GroupsFrogs and Toads

Order Urodela – they jumpSalamanders

Order Anura – long bodiesCaecilians

Order Apoda – legless, long bodies

III. The Amphibian Body:

A. Respiratory system tadpole - gills and skinadults – lungs and skin

B. Circulatory system1. double loop:

body to heart, lungs to heart2. 3 chambered heart

2 atria, 1 ventricle

C. FeedingFROGS and TOADS Herbivores as tadpoles Carnivores as adults

Eat anything they can catch!SALAMANDERS carnivores

Digestive system

Mouth Pharynx Esophagus Stomach Small intestine*

* liver and pancreas produce digestive juices Large intestine (colon) Cloaca –One opening for the removal of

waste, urine, eggs and sperm.

REPRODUCTIONCourtship dances (salamanders)Courtship calls (frogs/toads)

Male and female find each other with frog songs.

Each species has identifying “songs”

External fertilizationEgg layers –

eggs must be laid in water/or moist environment

Egg Incubation/Parent Behavior

Most species abandon eggs (frogs lay @ 200) Some species take great care of eggs

and young. Some species carry incubating eggs

on their back, in their mouth, in their stomach

Ex. male midwife toad

Adaptations for MovementEXAMPLES

Frogs and toads- large hind legs for jumping

- suction cups on feet

salamanders- body takes S shape

and springs forward