Frogs
and
Toads
Toads
• Toads have dry, warty
skin
• Generally found in
drier climates
• Stubby bodies with
short hind legs
• Parotid (poison) glands
behind the eyes
• Lay eggs in chains
Pelobatidae and Scaphiopodidae
Spadefoot toads
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•
•
•
Burrowing toads
Hardened protrusion on their foot for digging
Very quick metamorphic stage – 2 weeks!
Tadpoles are cannibalistic to speed up
metamorphosis
• Native to Europe,
W. Asia, and N. Africa
http://asm.wku.edu/froglogger/default.html
Bombinatoridae - Fire-bellied toads
• Brightly colored ventral sides
– highly toxic to predators!!
• Aquatic toads
• Unken reflex - the animal will
arch its back and limbs to
expose the bright belly
• Lay pigmented eggs in ponds
• Native to northeastern asia
Bufonidae - The TRUE Toads
• All members of their family
possess toad-like
characteristics
• Occur on every continent
except Australia and
Antartica
• Inhabit a variety of
environments
• Male toads possess a
Bidder’s organ – generally
inactive, but become an
active ovary!!
http://bioweb.wku.edu/froglogger/
Frogs
• Two bulging eyes
• Strong, long, webbed
hind feet designed for
jumping and swimming
• Smooth and slimy skin
• Lay eggs in clusters
Ascaphus - The Tailed Frogs – Wait a
minute…what?!!?
• Mostly aquatic
• Tail is an extension of the
cloaca – only found in males
• Minimizes sperm loss in
turbulent waters
• Use internal fertilization (other
frogs and toads use external)
• Primitive frogs – greater
number of vertebrae, lack the
ability to vocalize, and possess
free ribs
• Found in North America
Dendrobatidae - Poison Dart Frogs
• Arboreal and terrestrial
• Native to Central and
South America
• Brightly colored bodies to
exhibit toxicity to
predators
• Used to tip darts
• Piggy-back tadpoles once
they hatch
• Exhibit parental care
Medical Application
• Nerve toxins affecting the
nervous system and heart
activity
• Muscle relaxants, heart
stimulants, and appetite
supressants
• Skin may be 200 times
more potent than
morphine!
• One species has enough
poison to kill ten men!
Centrolenidae – Really cool Glass Frogs
• Coloration primarily lime green
• The internal organs, including the heart, liver,
and gastrointestinal tract are visible through
this translucent skin
Hylidae – Tree Frog
• Live in a variety of habitats including semiaquatic, terrestrial, and arboreal
• Pronounced forward eyes
• Adhesive pads on the toes and fingers
• Come in all different colors!!
http://bioweb.wku.edu/froglogger/
Ranidae – The TRUE frogs
• The widest distribution of any
frog family
• Occurs in all continents except
Antarctica
• Large, powerful legs and
extensive webbing on their feet
• Many are aquatic and most live
close to the water
• Some are arboreal and
burrowers
• Occur in all sizes – largest frog in
the world is the Goliath frog
http://asm.wku.edu/froglogger/default.html
Why are frog species important?
• Frogs are keystone species.
– A keystone species plays a critical role in
maintaining the structure of an ecological
community.
– Because they are sensitive to changes in the
environment, they may suffer from huge increases
in mortality.
• Can help to determine the overall
health of an ecosystem.
Why are frog species important?
• Invaluable tool for studying body systems.
– Dissections on frogs can be used to compare to
other vertebrates
• Important source of food
– Frog legs – taste like chicken?
• Medicinal purposes
– Poison dart frogs