Transcript Characteristics of Reptiles

Characteristics of Reptiles
By Jerit Owens
Scaly Skin
Dry thick skin covered with scales
 Prevents water loss
 Adds protection against predators
 Skin does NOT play a role in respiration in
reptiles. They can only respire through
their lungs.
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Skeletal Features Compared to
Amphibians
Legs are placed directly under body than
at right angles, unlike amphibians.
 This provides greater support for walking
and running.
 Reptiles have claws for catching prey and
for protection.
 More evolved jaws and teeth.
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Some have Four-chambered
Hearts
Most have three chambered hearts
 Crocodilians have four chambered hearts
 This separates deoxygenated blood from
oxygenated blood.
 Enables more oxygen to reach tissues.
 Supports high level of energy use.
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Reproduce on Land
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Lay eggs on land
No water larval stage, so
they are not at risk to water
predators like amphibians
No type of metamorphosis,
hatchlings look just like
adults
Evolution of the amniotic
egg freed reptiles from
reproduction in water.
Amniotic egg nourishes and
protects the developing
embryo in terrestrial
habitats.
Reproduce on Land (cont’d)
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Embryo relies on egg for
survival until it hatches.
All have internal
fertilization
Eggs are laid after
fertilization
Reptiles lay eggs in safe
places, away from
predators
Most reptiles provide no
care for hatchlings.
Reptiles are Ectotherms
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This lizard is sun bathing to
get warm.
Similar to amphibians
because they are both
ectotherms.
Rely on outer
environment for
regulation of body
temperature.
Because of this feature,
they don’t live in
extremely cold regions.
Many become dormant in
cold seasons.
Obtaining Food
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Slow animals like turtles
and tortoises are
herbivores or they prey
on worms and mollusks.
Fast turtles can prey on
fish and amphibians
Most lizards eat insects
Marine iguanas from the
Galapagos Islands eat
algae.
Komodo dragons are
carnivorous and feed on
large animals including
humans.
This marine iguana is brightly
colored from eating algae in
the Galapagos Islands.
Obtaining Food (cont’d)
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Some snakes like
rattle snakes have
fangs for capturing
prey.
Other large snakes
use methods of
constriction to
suffocate their prey.
Sense Organs
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This image shows the
Jacobson’s organ.
Some snakes have heatdetecting pits below their eyes,
to detect warm prey.
Snakes and lizards flick their
tongue to sense chemical
molecules in the air.
They then pull the tongue into
the mouth and insert it into a
structure call the Jacobson’s
organ.
This organ performs a
chemical analysis of the
molecules that are on the
tongue