1. Phylum Chordata
Tunicates
Amphioxus
Phylum Chordata

2. Phylum Chordata
Included are 48,000 species the majority of which are vertebrates
1,400 species are invertebrates
All chordates share 4 characteristics at one point throughout the lifecycle
Includes the tunicates, the lancelets (Amphioxus), and vertebrates
Phylum Chordata

3. Taxonomic Summary Phylum Chordata Subphylum Urochordata
Subphylum Cephalochordata
Subphylum Vertebrata
Phylum Chordata

4. Subphylum Urochordata
Defining characteristics
Notochord and nerve cord are found only in the larval stage
Most of the urochordates are filter feeders
Phylum Chordata

5. Colonial Species
Phylum Chordata

6. Nice Tunic Soft exoskeleton made of cellulose with 2 external openings
Some species have spicules and toxins in the tunicate
Spicules
Phylum Chordata

7. Filter Feeding

8. Sexual Reproduction
Most colonial species retain eggs and fertilization is internal with development
The larvae are microscopic, short-lived, non-feeding, pelagic tadpoles
Phylum Chordata

9. Subphylum Cephalochordata
Defining characteristics
The notochord extends beyond the nerve cord to the anterior end of the animal
The notochord is contractile, formed as a longitudinal series of flattened discs
Phylum Chordata

10. A Little Ditty It’s a long way from amphioxus, It’s a long way to us
To the meanest human cuss
Goodbye to tails and gill slits,
Hello: nails and hair!
But we came from there
Phillip H. Pope sing to the tune of “It’s a long way to Tipperary”
Phylum Chordata

11. Anatomy
Diagnostic chordate features are found in both the larvae and adult
Resemble small fish with a poorly developed head
Have cirri around a large mouth
V-shaped body muscles (myomeres) extends the length of the body and are used for swimming and burrowing
Phylum Chordata

12. Anatomy
Phylum Chordata

13. Filter Feeders
Filter feed using a special pharynx similar to tunicates
Slotted pharynx supported by skeletal bars similar to acorn worms
Phylum Chordata

14. Reproduction Separate sexes with gonads located in the atrial region
Fertilization occurs in the water
Developing young are free swimming propelled by cilia
Phylum Chordata