1. Phylum Chordata
“String/Cord”

2. Common Characteristics
All chordates have the following characteristics at some point in their life
In many vertebrates, certain features may only be present as an embryo

3. Common Characteristics
Pharyngeal slits – series of openings that connect the inside of the throat to the outside of the "neck". Often, but not always, used as gills
Dorsal nerve cord - bundle of nerve fibers which runs down the "back". Connects the brain with body regions/organs

4. Common Characteristics
notochord - cartilaginous rod running underneath, and supporting, the nerve cord. This is the “backbone” of vertebrates
post-anal tail - an extension of the body past the anal opening

5. 3 major sub-phyla Subphylum: Cephalochordata (head cord)
AKA Lancelets or “Amphioxus”
First animals with a spinal cord
Exclusively marine, roughly fish shaped
Can swim, but usually buried in sand with anterior end exposed
Filter feeders
Oral hood lined with cilia creates water flow
Water exits through atriopore

6. Lancelets or “Amphioxus”

7. 3 major sub-phyla Subphylum: Urochordata (tail cord)
Class: Ascidiacae (little bag) – sea squirts or Tunicates
Adults are sessile, with sac like protective tunic
Larva are free swimming with chordate feature
plankton feeders (filter feeders)
Class: Larvacea (ghost like)
Free swimming throughout life
as adults, they resemble larvae ascidian

8. Ascidiacae (Tunicates)

9. Larvacea (ghost like)

10. 3 major sub-phyla – Urochordata cont…
Class – Thaliacea (luxuriance ) Sea Salps
barrel shaped
plankton feeders (filter feeders)
bioluminescent = phosphorous

11. Subphylum Vertebrata “joint of the spine”
Largest group of chordates (58,000 species)
Vertebrates make up 5% of all animal species
Range in size from 0.3” species of carp to 110’ Blue Whale.
Bilateral symmetry
Includes 7 classes

12. Class Agnatha – “no jaws”
Lamprey eel (sometimes parasitic to fish), Hagfish
Jawless, circular mouth, usually with retractable teeth
Notochord is a flexible cartilage rod
Lack paired appendages

13. Class Chondrichthyes “cartilage fish”
Sharks, rays, skates
Approx. 750 species
Skeleton is cartilage, not bone
No ribs
Paired appendages

14. Class Osteichthyes “bony fish”
All fish that have bony skeletons
Largest class of vertebrates (29,000 species)
All possess gills for aquatic respiration
Largest species is Ocean Sunfish (11’, 5,000 lb)
Dwarf Pigmy Goby is smallest (0.59”)

15. Class Amphibia “dual life”
Frogs, toads, salamanders, caecilians
Approx. 6,500 species
Adapted to life in water or on land
Most are 4 limbed
Gas exchange through lungs, gills, & skin

16. Class Reptilia “to creep”
Snakes, turtles, lizards, alligators
Over 8,000 species inhabit every continent except Antarctica
All reptiles have scales
All reptiles breathe through lungs

17. Class Aves “flight” 10,000 living species of birds
Most species of all tetrapod vertebrates
Inhabit every ecosystem on Earth
All birds have feathers and wings
Sternum is keeled for attachment of flight muscles – the “wish-bone”

18. Class Mammalia “breast”
Over 5,000 species
Mammary glands produce milk
Hair or fur for protection
Almost all give birth to live young, nourished by placenta
Able to maintain body temp. internally
Largest brains of all vertebrates