3. Why study herpetology?
Important implications for conservation,
research and education
o Amphibians are excellent bio-indicators for
environmental quality and change.
o Snake venom is proving to be very useful to the
medical field (dissolving blood clots in heart attack
and stroke victims).
5. Amphibians as Bio-indicators
•Because amphibians absorb water
through their skin, they are often the
first to suffer the effects of water or
environmental pollution.
•Nearly 1/3 (32%) of amphibians
worldwide are threatened
•Nearly 168 species are believed to
have gone extinct
•43% of species are in decline
6. Major reasons for decline:
•Habitat destruction
•Chytridiomycosis (a fungal disease)
Other factors:
•Introduction of non-native species
•Over-exploitation (pet trade)
•Climate change; amphibians are very sensitive to
small temperature changes, which can affect their
breeding habits, reproduction and immune response
•UV-B radiation (due to decreases in stratospheric
ozone layer)
•Chemical contaminants (pesticides, heavy metals,
acidification and nitrogen based fertilizers)
7. Amphibians: Means “double life”
• Have gills and lungs
• Are cold-blooded
• Most lay soft, gel-covered eggs (exceptions include
the Fire Salamander, some African Toads and most species of
Caecilians)
• Are vertebrates
• Many have toxic secretions as defense
17. Newts:
• All newts are salamanders, but not all
salamanders are newts.
• Newts have three distinct life stages
– Aquatic larvae (tadpole)
– Terrestrial adult (eft): 1 to 3 years
– Aquatic adult (newt)
21. Salamander Biodiversity:
• Salamanders can be aquatic, terrestrial, or a
mixture of both. Living in diverse habitats cause
different species to use different types of
respiration.
Types of Respiration:
• External gills
• Lungs
• Skin/cutaneous respiration
(all salamanders can do this)
22. Aquatic Habitat:
• Larvae are born in water using
external gills
• Juveniles and adults breathe through
external gills if retained, skin if not
• Breathing through skin requires
constant moisture, easy if aquatic
(example: Mudpuppy)
23. Terrestrial Habitat:
• Most terrestrial salamanders lay eggs in the
water that hatch into aquatic larvae that later
crawl out on land.
• A few species lay eggs on land that hatch into
juveniles.
• Juveniles and Adults breathe through skin and
lungs if present
• If lungs are lacking the salamander must live
in a moist area to breathe through its skin
(ex.: Spotted Salamander)
24. Semi-Aquatic:
•Larvae are born in water and breath through
external gills
• Juveniles crawl out on land and breathe using
lungs.
•Adults return to the water using skin to breathe,
and occasionally venture on land using lungs.
(example: Eastern Red Spotted Newt)
25. What they Eat:
Mostly insects, however, any animal they can fit in
their mouth is fair game (including smaller salamanders!)
Aquatic salamanders use chemical signals to track prey
Terrestrial salamanders use vision to detect movement
What Eats Them:
Birds and snakes on land
Fish and turtles in the water
26. Salamander eggs have a firm, outer
jelly coating that encases the eggs.
These are Spotted salamander eggs.
33. Differences between the two
Pickerels have a double row Southern Leopards have irregular spots
of spots on their backs and a white spot on the eardrum
46. • Reptiles are vertebrates.
• Reptiles are covered in scales or have scutes.
• Reptiles breathe with lungs.
• Most reptiles lay hard-shelled eggs. Some
reptiles, like pit vipers, give birth to live young.
• Almost all reptiles are cold-blooded. (One
exception is the leatherback sea turtle, which can
regulate its body temperature to some degree.)
47. Snake Characteristics
• Snakes have clear scales over their eyes so they do not have eyelids for
blinking or closing their eyes.
•Snakes do not have ears so they do not hear as we do. They feel
vibrations.
•Snakes use their tongues for smelling using the Jacobson’s organ
•The pits on venomous snakes detect thermal infrared radiation. The
pits respond to subtle thermal fluctuations in the environment and
allows for an accurate measurement of the distance of a heat source.
•Non-venomous snakes do not have fangs, but have rows of pointed
backward-curved teeth
•A snake’s jaws can come apart so that they can eat large prey.
•Snakes will shed their skin several times a year as they grow.
64. Turtle Characteristics
• Do not have teeth
• Usually omnivores
• Lay eggs and leave them. Many eggs are
eaten by predators, such as raccoons, skunks,
coyotes, dogs, crows and snakes.
• Box turtle populations are in decline due to
habitat loss, road mortality and collection by
humans.
