1. CHORDATA

2. Characteristics of ALL Chordates
An animal that has, for at least some stage of its life,
A dorsal, hollow nerve cord
A notochord
Pharyngeal pouches (gill slits)
A post-anal tail

4. Characteristics: The Notochord
All chordate embryos have a notochord, a stiff but flexible rod that provides internal support
Remains throughout the life history of most invertebrate chordates; among, present only in the embryos of vertebrate chordates

5. Characteristics: The Nerve Cord
= Spinal Cord
A fluid-filled tube of nerve tissue that runs the length of the animal, dorsal to the notochord
Present in chordates throughout embryonic and adult life

6. Characteristics: The Pharyngeal Pouches
Pairs of opening through the pharynx
Invertebrate chordates use them to filter food
Juvenile fishes use them to them for breathing
In adult fishes the gill sits develop into true gills
In reptiles, birds, and mammals the gill slits are vestiges, occurring only in the embryo

7. Characteristics: Postanal Tail
Tail that runs past the anus.
The notochord and nerve cord extend to the tail
Found at some time during a chordate's development

8. Invertebrate Chordates
Subphylum Urochordata
Subphylum Cephalochordata
Possess all characteristics as larva, but loose notochord (backbone) as develop

9. Subphylum Urochordata
Marine animals; some species are solitary, others are colonial.
Sessile as adults, but motile during the larval stages
Settle head first on hard substrates and undergo a dramatic metamorphosis (e.g., tail, notochord, muscle segments, and nerve cord disappear)
Model organism: Tunicates

10. Subphylum Urochordata

11. Subphylum Urochordata
Tunicates are filter feeders; plankton is trapped in a sheet of mucus and cilia later direct the food-laden mucus to the stomach
Water leaves the animal via an excurrent siphon

12. Subphylum Cephalochordata
Exclusively marine animals
Although they are capable of swimming, they usually are buried in the sand with only their anterior end being exposed

13. Subphylum Cephalochordata
Model Organism: Lancelets
Have closed circulatory system and diffuse gas through their skin

14. Subphylum Vertebrata Most of chordates Have a backbone Classes:
Agnatha  Jawless Fish
Chondrichthyes  Cartilage Fish
Osteichthyes  Bony Fish
Amphibia  Amphibians “Double Life” Organisms
Reptilia  Reptiles
Aves  Aves
Mammalia  Mammals

15. Class Agnatha
Jawless Fish
All ancient
Armored body plates
Lampreys

16. Class Chondrichthyes Cartilage Fish Sharks & Rays
Skeletons = Cartilage, not bones
Have scales & biting mouth parts
Complete digestive system with large stomach for infrequent meals
Constantly move in order to
breath

17. Class Osteichthyes Bony Fish Flounder, Blue Gill Skeletons = Bones
Paired fins, scales, gills
Two types: Ray-finned & lobe-finned
External fertilization, little care for young

18. Class Amphibia Amphibians
Double life  throughout metamorphosis change their habitat
Eggs  Tadpole (gills/difusion)  Frog (lungs)
Tetrapods (move on 4 legs)
Movable & separate head
Wide sensory system
Accordion muscle
movement

19. Class Reptilia Reptiles
4 types: Turtles, Crocodiles, Tuataras (ancient lizard-like), Lizards/Snakes
Cold blooded
Lay eggs (amniotic, w/ internal fertilization)
Dry, scaly skin
Hunters
Vision = dominant sense; hear cibrations
Ectotherm (use outside for heat)

21. Class Aves Birds Eagles, robins, ducks, herons
Wings, feathers, endothermic (can regulate heat themselves), high metabolic rate, hollow bones (allows for flight), lays eggs
Types: Waterfowl, Perching, Predatory, Song, Ground Birds
Specialized beak to food source

24. Class Mammalia
3 Subclasses (Eutheria = placental animals; Metatheria = immature young / pounches; Prototheria = lays “eggs” from belly pore)
17 Orders
Hair, nurture young, 4 chambered hearts, viviparious  give birth to live young
Claws, nails, tails
Color vision
Young get nutrition from mother’s milk
High metabolic rates
Endothermic