1. Chordates and Vertebrates
At one time in their development ALL chordates have:
Notochord – flexible, rod-like structure along the back of the organism
Postanal Tail
Nerve cord-tubular bundle of nerves that lies above the notochord.
Gill Slits – paired openings located in throat behind mouth. Develop into gills in fish. Traces can be seen in embryos of many vertebrates INCLUDING humans!

2. Vertebrates Have a backbone that encloses the nerve cord.
Most are ECTOtherms – internal body temp. changes with its surroundings (fish, amphibians, & reptiles)
ENDOtherms – animals with constant internal body temp. (Birds & Mammals)
Endoskeleton: internal framework of bone and cartilage

3. 7 Vertebrate groups Jawless Fish Cartilaginous Fish Bony Fish
Amphibians
Reptiles
Birds
Mammals

4. Fish Ectotherms Adaptations for water:
Gills- organs for exchanging gas
Fins – fan like structures, used for moving, balance, and steering
Scales – hard thin plates that cover skin, provides protection
3 classes: Jawless, Cartilaginous & Bony

5. Jawless Fish
Round mouths w/ long, tube-like bodies covered in slimy skin w/ NO scales.
Flexible bodies made of cartilage.
EX: Lamprey & Hagfish

6. Lamprey
HAGFISH

7. Cartilaginous Fish Skeletons made of cartilage Movable jaws & Scales
Skate
difference btw skate & ray
Cartilaginous Fish
Skeletons made of cartilage
Movable jaws & Scales
Ex: Sharks, Skates & Rays
Ray

8. Bony Fish 95% of all species of fish Gills protected by gill cover
Swim Bladder
Most have separate sexes
Reproduce by females releasing large # of eggs, & then males swim over eggs and release sperm. Call this spawning.
Form of External fertilization

9. 3 Classes
Lobe-finned Fish
Rayfinned fish
Lung fish

10. Swim Bladder
Buoyancy – ability of a liquid or gas to exert an upward force on an object in it.
Swim bladder allows it to adjust its density so it can rise or sink.
Fills with gas-rises. Deflates-sink.

11. Amphibians
Ectothermic vertebrates that spend part of their life in water & part on land.
Ex: Frog, toad & salamander
Greek word “amphibios” means double life

12. Amphibian Adaptations
Respiration:
-Moist, smooth, scaleless skin that allows gas to be exchanged (breathe through skin)
-Also have small lungs to aid in breathing.
Hibernation – inactivity in winter
Estivation – inactivity in hot, dry summer months.
Eggs have no shell, so they must return to water to lay eggs.

13. Difference Between Frogs & Toads
smooth or slimy skin  strong, long legs  webbed hind feet two bulging eyes lay eggs in clusters
TOADS
warty and dry skin  stubby bodies with short hind legs  Most have glands on their back that secrete poison
lay eggs in long chains 

14. Salamanders & Newts Long, slender bodies
Short legs that appear to come straight out of their side
Often found under dead leaves and rocks during the day
Often nocturnal, feeding on worms, crustaceans and insects
Difference btw salamander & Newt

15. Amphibian Metamorphosis
-Egg
-Tadpole (aka polliwog) spends its time swimming in the water, eating and growing. Uses gills to breathe, presence of a tail
-Tadpole w/ legs: tadpole sprouts legs and arms, head becomes more distinct
-Froglet: stage before the adult frog. Tail is less prominent.

16. Amphibian Metamorphosis
Metamorphosis: the development of an animal from a larvae into an adult
Amphibians usually complete their life cycles in two environments
Larvae: water
Adult: land
**Rate of metamorphosis depends on species and nutrients available

17. Reptiles Ectothermic vertebrate Dry, Scaly skin
Often show maternal care (take care of eggs or young)
Ex. Snakes, lizards, alligators, turtles

18. Adaptations for Life on Land
Thick, dry skin covered with scales
4 legs with claws that hold body off ground (except snakes)
Amniotic egg
~provides environment for embryo to develop
~leathery shell
Reptiles breathe with LUNGS!

19. 3 Orders of Reptiles
Turtles
Crocodiles & Alligators
Lizards & Snakes

20. Turtles Body covered by hard shell on both top & bottom
Most can withdraw partially into shell for protection
Have a BEAK (no teeth)

21. Crocodiles & Alligators
Crocs:
Long, slender snouts
Both bottom (4th lower tooth)& Top teeth stick out when jaw closed
Found all over world
Aggressive
Alligators:
Broad snouts
Only top teeth stick out, bottom teeth have spots to fit in so you do not see them.
Found only in South East USA and China

23. Lizards & Snakes Largest group of Reptiles!
Moveable eyelids
External ears
Legs with clawed toes
Snakes:
No moveable eyelids, external ears, or legs with clawed toes
Hear by vibrations picked up by lower jaw bone

24. Venomous vs. Poisonous There are NO poisonous snakes!!! Only Venomous
Venom must be injected into the target
Poison…found in skin or meat…can cause problems if eaten or you come in contact with it (ex Dart frogs)