Frogs and Toads
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Transcript of Frogs and Toads
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 ScaphiopodidaeSpadefoot toads
• 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 semi-aquatic, 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