Part lll : Animals
Reptiles & Amphibians
Reptiles
Terrestrial Adaptations:
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Toes with claws to dig & climb
Dry, watertight skin covered by scales to prevent desiccation (water loss)
May bask or lie in sun to raise body temperature or seek shade to lower body temperature; known as thermoregulation
Ectothermic - body temperature controlled by environment
Snakes use scales & well developed muscular & skeletal systems to move
Geckos have toes modified into suction cups to aid climbing
Reptiles
Lungs for respiration
-
Double circulation of blood through heart to increase oxygen to cells
Water conserved as nitrogen wastes excreted in dry, paste like form of uric acid crystals
Partial separation in ventricle to separate oxygenated & deoxygenated blood
Reptiles
- Amniotic Egg
- Protective membranes & porous shell around embro
- Shell leathery & waterproof
- Internal fertilization before shell is formed
Crocodile
- Eyes located on top of head so they can see when submerged
- Nostrils on top of snout to breathe in water
- Valve in back of mouth prevents water from entering airway when feeding underwater
- No parental care of young in most species except Nile crocodile that carry young in their jaws & guards nest
Lizard
- Four limbs
- Rely on speed, agility, & camouflage to catch prey
- Feed on insects & small worms
- Some, such as anole & chameleon, can change colors for protection
- May use active displays such as squirting blood, hissing, or inflating bodies
Snake
Poisonous:
- Elliptical pupil
- Nostril pit
- Scales on underside of tail in single row
Non - Poisonous:
- Round pupil
- Nostril with no pit
- Scales on underside of tail in double row
Amphibians
- Both internal and external nares (nostrils)
- Lungs instead of gills
- Double loop blood circulation to lungs and rest of body cells
- Four limbs with claw on digits (toes)
- Three chambered heart (two atria and one ventricle)
- Necks help to see much easier and to feed
- Skin with keratin (protein) to prevent water loss
Amphibians
- Ectothermic - body temperature changes with environment
- Show dormancy or torpor (state of inactivity during unfavorable environmental conditions)
- Most with smooth, moist skin to take in dissolved oxygen
- Some with oral glands to moisten food they eat
- Hibernate in winter and aestivate in summer
- Webbed toes with claws
- Aquatic larva called tadpole goes through metamorphosis to adult Metamorphosis
Amphibians
External fertilization with amplexus (male clasps back of female as sperm & eggs deposited into water
-
Eggs coated with sticky, jelly like material so they attach to objects in water & do not float away
Well developed muscular system
Digested system adapted to swallow prey whole
Males with vocal sacs to croak
Eggs hatch into tadpoles in about 12 days
Frog
Frog skin smooth & moist for cutaneous respiration
Toad
Toads is rough & warty with poison glands
Frogs & Toads ID Traits
Resources :
- A Field Guide to Western Reptiles and Amphibians, by Robert C Stebbins (2003)
- The National Audubon Society Field Guide to North American Reptiles and Amphibians by John L. Behler and F, Wayne King.
- A Field Guide to Reptiles & Amphibians: Eastern and Central North America, by Roger Conant and Joseph T. Collins (1998),