Amphibians
Classification
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Kingdom: Animalia
Phylum: Chordata
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Subphylum:
Vertebrates
Class: Amphibians
Examples- frogs,
toads, salamanders
newts
The Link
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Amphibians-link
between aquatic fish
& terrestrial reptile
animals.
Have adaptations to
move habitat from
water to land
“Amphibian” means
“double life”
Aquatic Ties
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Larvae
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Gills
Tails
Algae eaters
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Moist skin
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Herbivores
Will suffocate if can’t
get rid of CO2
Adult
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Must lay eggs in H2O
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Lack outer shell
Costa Rica-Tree Frog Eggs
Terrestrial Ties
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Adults
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Lungs + Moist skin
Legs
Carnivores
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Insects/amphibians
More efficient heart
Evolution of an Amphibian
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360 million years ago
Evolved from lobed-fin
fish
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Bones in pectoral
(forearms) and pelvic fins
(hind legs)
Homologous structures
Leg bones-stronger
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To support the body’s
weight
Evolution of an Amphibian
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Formation of rib cage
protects internal organs
Evolution of an Amphibian
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Lateral line (vibrations in H2O) evolved
into Tympanic membrane (vibrations in
air)
Evolution of an Amphibian
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Eyelids & nictitating membrane
(goggles, keep moisture in)
Evolution of an Amphibian
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Nares-detect air borne
scents
1st amp.-large
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# vertebrate on land
went up
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no competition for food
smaller-survived
Climate changed
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decrease # and size
Traits of Amphibians
1. Metamorphosischange form
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Aquatic larvae=
terrestrial adult
Traits of Amphibians
2. Cold-blooded-ectotherms
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Use environment to regulate temperature
Traits of Amphibians
3. Ext. fertilization
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Need H2O
Jelly-coated Eggs
No shells
Traits of Amphibians
4. Feet, if present, lack claws
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Often webbed
Traits of Amphibians
5. Moist porous skin
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Cutaneous Respiration
 In O2 & H2O
 Out CO2 & H2O
Traits of Amphibians
6. Respire = gills,
lungs, skin
Number of species
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4500 different
species of
amphibians
Anura
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Means: tailless
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Lay jelly-coated
eggs in H2O
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3800 species of frogs
& toads
Tadpoles- compact
bodies
Tongue sticky, long
Anura
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Frog
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Smooth skin
Jump= powerful hind
legs
Live near H2O
Toad
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Rough bumpy skin
Poisonous glands
Only walk
Live on land (moist)
Urodela
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400 different
species=
salamanders& newts
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Long tails
Elongated bodies
Moist skin
4 limbs
Lay eggs in H2O
Worldwide- except
Australia
Apoda or Gymnophiona
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“legless” amphibians
160 species
Caecilians
12” long
Live tropics in
dirt/soil
Eat Insects
Life of a Frog (Metamorphosis)
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Larvae (fish-like)
 Gills
 Fin-like tail
 2 chamber heart
 Closed system
 1 loop
Life of a Frog (Metamorphosis)
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Adult
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Lungs
Legs
Closed system
3 chamber heart
2 loop system
External covering/moist skin
1. Respiration
(cutaneous)
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thin, moist skin-if
skin dries suffocation
b/c increase CO2
Most active @ nightcooler, more
moisture
Mucus glands- more
moisture
2. Protection
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Some poisonous
Most secrete a foul
tasting substance
Skin-camouflaging
“Extra Eyes”
Puff-up eyes/bodies
Poison Dart Frog
Nervous system/Sensory
Organs
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Same size as fish
No care process for
young
Sight-well developed
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Eyes=large @ top
Detect prey
Eyelids
Nictitating membrane
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“goggles” while
swimming
Keep eyes moist
Nervous System/Sensory
Organs
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Sound- tympanic
membrane
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Pick up vibrations
Connects to
Eustachian Tube
NOT EARS!!!!
Smell-Nares
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Internal & External
High Set
Internal Structures
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Endoskeleton
Adaptations:
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Radius, ulna are
fused
Tibia,fibula fused
Beginning of joints
Digestive System
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Larvae-herbivores
Adult-carnivores
Starts in the mouth
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2 kinds of teeth
Gripping/holding prey
Forcing it down gullet
DO NOT CHEW!!!!!
Pharynx (back of throat)
Gullet (opening to
esophagus)
Esophagus
Stomach
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Where protein digestion
occurs
Digestive System
heart
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Small intestine
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No pyloric caeca
Small
Proteins, lipids, & carbs. intestines
digestion
Get enzymes from
pancreas (insulin), liver
(makes bile), and gall
Large
bladder (stores bile)
intestines
Large intestine
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NO DIGESTION
Removes excess H2O
Food molecules absorbed
into blood
Storage of food until sent
to cloaca to be removed
liver
Digestive System
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Cloaca
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Similar to the urogenital
opening BUT…
Digestive AND urogenital
systems meet here
Stores urine, sex cells, &
feces until released
Vent
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Similar to anus
Everything exits hereurine, sex cells, feces.
Circulatory System
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Larvae (fish-like)
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ills
**Larvae
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ody
1 loop system
2 chambered heart
Adult
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2 loop system
3 chambered heart
Circulatory System
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Systemic Circulation
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blood travels from heart
to body and back to
heart
Pulmonary Circulation
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blood travels from heart
to lungs and back to
heart
Blood Circulation
Respiratory System
2 types:
 Respire through moist
skin-cutaneous
 Mouth-Glottis (opening to
trachea) -Trachea-Lungs
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Take in O2 and release
CO2
“Purple bunch of grapes”
Lungs
Excretory System
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Kidneys
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2, lie along back wall
of frog, under
reproduction organs
“Long, brownish-red
kidney beans”
Blood into kidney
Kidneys filter out
nitrogenous wastes
Excretory System
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Passes through tube
called ureter
Urea, salts & H2O
(urine) stored in
urinary bladder
From cloaca, urine
passes out through
vent
Reproductive System
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Male Frog:
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Sperm made in
testes
Travels through
sperm ducts to
cloaca
Exits out vent
Reproductive System
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Female Frog:
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Eggs made in ovaries
Travel along oviduct
where jelly-coating is
applied
Eggs empty out into
cloaca & exit out vent
when amplexus occurs
Fat Bodies
Female Eggs &
Oviducts
See “Love is In the Air”
Fun Bio-Nerdy Amphibian Facts
Group of frogs= Army
 Group of toads= Knot
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Fears…
Batrachophobia- Fear of amphibians
Ranidaphobia- Fear of frogs.
Bufonophobia- Fear of toads.
Smallest frog= ~1cm
Largest Frog= 30cm (~1 ruler)
Largest Salamander
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Chinese Giant Salamander – critically
endangered
Close Eyes to Swallow
Toads CANNOT give you warts!!!
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Human Papilloma Virus (HPV)
Gastric-Brooding Frog
Glass Frog-See Heart Beating
The End-Hop to It!!!