1. Phylum Chordata
The Chordates!

2. All chordates have these 4 characteristics at some point in their lifetime:
Dorsal Hollow Nerve Cord: a nerve cord that runs along the back (later becomes brain/spinal cord)
Notochord: long, supporting rod that runs below the DHNC (becomes backbone/vertebral column)

3. Pharyngeal Slits (pouches): slits in the throat that help with gas exchange in some animals (as a fetus, humans lose these in favor of lungs)
4. Post-Anal Tail: at some point in their lives, all chordates have a tail that extends past the anus

4. Tunicates (sea squirts) Lancelets
Most chordates are vertebrates but there are some non-vertebrate chordates.
The two groups of non-vertebrate chordates (chordates without backbones) are:
Tunicates (sea squirts)
Filter feeders that live in the ocean
Soft-bodied
Show all the characteristics of chordates as LARVAE—not as adults
Lancelets
Small, fish-like creatures that live on the ocean floor
Unlike vertebrates, their notochord (spine) extends into their head

5. Tunicates
Take in water through incurrent (oral)siphon and releases it through excurrent (anal) siphon

6. SO… Phylum Chordata includes:
3 subphyla:
Subphylum Urochordata (tunicates)
Subphylum Cephalochordata (lancelets)
Subphylum Vertebrata (vertebrates)
Vertebrates: fishes, amphibians, reptiles, birds, and mammals

7. Vertebrates include: fishes, amphibians, reptiles, birds, and mammals
All vertebrates have:
A backbone
Bilateral symmetry
Endoskeletons
Closed circulatory systems
Complex brains & sensory organs
Efficient respiratory systems

9. Introduction to Fish
Jawless Fish
Lamprey, Lamprey, Part 2
Hagfish