"Amphibian” comes from the "Amphibian” comes from the Greek meaning "both life". Greek meaning "both life". Amphibians can live on water Amphibians can live on water and on land. and on land.

Scientist infer that Scientist infer that amphibians evolved from amphibians evolved from lobe-finned fishes called lobe-finned fishes called crossopterygians.crossopterygians.

FROG LATIN meaning

KINGDOM _____________

PHYLUM ____________________________

SUBPHYLUM ___________________________

CLASS _______________________________

ORDER _____________________________

ANIMALIA

CHORDATA

VERTEBRATA “backbone”

AMPHIBIA “double life”

ANURA “without a tail”

CharacteristicCharacteristics of Frogs of Frog

Frogs are cold-blooded, which Frogs are cold-blooded, which means their blood temperature means their blood temperature rises and falls with that of the rises and falls with that of the

surrounding environmentsurrounding environment

• ••

They use gills, lungs, skin, and They use gills, lungs, skin, and mouth cavity in respiration.mouth cavity in respiration.

They have moist, smooth, thin skin with no They have moist, smooth, thin skin with no scales.Feet are webbed and the toes lack scales.Feet are webbed and the toes lack

clawsclaws..

Frogs have many prominent characteristics that are Frogs have many prominent characteristics that are adaptations to a life spent both on land and in water:adaptations to a life spent both on land and in water:

They change from an aquatic larval stage to a They change from an aquatic larval stage to a terrestrial adultterrestrial adult

form. This transformation is called metamorphosisform. This transformation is called metamorphosis

Frogs enter a state of dormancy Frogs enter a state of dormancy when conditions are when conditions are unfavorable.unfavorable.They often bury themselves in They often bury themselves in mud or leaves, emerging when mud or leaves, emerging when conditions are better. conditions are better.

Such states of Such states of inactivity are known inactivity are known

as known as:as known as: Hibernation when it Hibernation when it occurs in the winteroccurs in the winter

Estivation when it Estivation when it occurs in the summeroccurs in the summer

HIBERNATION/ ESTIVATION

Images from: http://www.enc.org/Classroom_Calendar/CC_Units/Unit_Images/185.jpg http://www.reptilis.org/pyxi/image5.htm

FAT stored in FAT BODIES provides energy

Thin, moist skin – no scales

Mucous glands make it “slimy”

Camouflage- for protection

Some have poison glands

http://www-binf.bio.uu.nl/dutilh/hall/kikkers.html

Larvae have two-chambered hearts; Larvae have two-chambered hearts; adults have three-chambered hearts and adults have three-chambered hearts and

well-developed circulation.well-developed circulation.

Eggs lack multicellular membranes or Eggs lack multicellular membranes or shells. They are usually laid in water or in shells. They are usually laid in water or in

a moist environment and fertilized a moist environment and fertilized externally.externally.

Classification of Classification of AmphibiansAmphibians

Frogs and toads comprise the Frogs and toads comprise the order Anuraorder Anura

There are about 3,500 known There are about 3,500 known species of frogs and 300 species of frogs and 300

kinds of toadskinds of toads

They are found on every They are found on every continent except Antarcticacontinent except Antarctica