1. Phylum Chordata

2. Chordates are divided into 2 groups:
Phylum Chordata:
Chordates have, for at least one stage of their life:
A dorsal (top), hollow, nerve cord
A Notochord – a long supportive “backbone”
Pharyngeal pouches – gills or gill slits
A tail
Chordates are divided into 2 groups:
Hollownerve cord
1. Nonvertebrate Chordates
(no vertebrae)
Subphylum Urochordata
Subphylum Cephalochordata
2. Subphylum Vertebrata
(have vertebrae)
-Jawless Fish
-Class Chondrichthyes
-Class Osteichthyes
-Class Amphibia
-Class Reptilia
-Class Mammalia
Notochord
Tail
Pharyngeal pouches

3. KingdomAnimalia Invertebrates Vertebrates Phylum Chordata
is divided into two groups
Invertebrates
Vertebrates
Phylum Chordata
is divided into groups
Nonvertebrate Chordates
Subphylum Vertebrata
includes
includes
Class Chondrichthyes
Class Osteichthyes
Class Amphibia
Jawless Fish
Subphylum Urochordata
Subphylum Cephalochordata
Lampreys & Hagfish
Sharks & Rays
Bony fish
Amphibians
Tunicates
Lancelets
Class Reptilia
Class Mammalia
Reptiles
Mammals

4. Diversity of Phylum Chordata

5. Phylum Chordata: Nonvertebrate Chordates
Subphylum Urochordata
Tunicates
“Sea Squirts”
Marine filter-feeders
Although do not have vertebrae, still have a hollow nerve cord, notochord, pharyngeal pouches, and a tail
Subphylum Cephalochordata
Lancelets
Live on sandy marine bottom
Catch food in mucus of mouth, swallow mucus for digestion
No heart, blood circulates by contracting blood vessels
Although do not have vertebrae, still have a hollow nerve cord, notochord, pharyngeal pouches, and a tail

6. Phylum Chordata: Subphylum Vertebrata
Jawless Fish: Lampreys & Hagfish
Class Chondrichthyes: Sharks & Rays
Class Osteichthyes: Bony Fish
Class Amphibia: Amphibians
Class Reptilia: Reptiles
Class Mammalia: Mammals

7. Phylum Chordata: Subphylum Vertebrata: Jawless Fish
Lampreys (Superclass Agnatha)
Present in North American waters
Parasites that attach to other fish
Circular disk mouth has many teeth and a rasping tongue that scrapes away flesh then feeds on tissues and fluid
Hagfish (Superclass Agnatha)
Lack eyes and have 4-6 tentacles around mouth
Feed mostly on dead or dying fish
Use a toothed tongue to scrape away a hole
Able to tie themselves into knots

8. Phylum Chordata: Subphylum Vertebrata: Class Chondrichthyes
Cartilaginous Fish
Sharks, Rays (some are electric) & Skates, Sawfish, & Chimaeras
Skeleton made of cartilage not bone, rough skin have tooth-like scales and feel like sandpaper
Most have gill slits
350 different species of sharks, have thousands of teeth arranged in several rows
Some sharks are filter-feeders
The largest of Rays feed on plankton

9. Phylum Chordata: Subphylum Vertebrata: Class Osteichthyes
Detect gentle vibrations using sensitive receptors that form the lateral line system
Maintain buoyancy with an internal, gas-filled organ called a swim bladder
Bony Fish
Skeletons made of hard calcified tissue called bone
Respire using gills
Brain
Gills
Spinal cord
Operculum

10. Phylum Chordata: Subphylum Vertebrata: Class Osteichthyes
Bony Fish
Ray-finned fish
Most diverse of all Chordata
Salmon
Trout
Sturgeon
Bluegill
Northern Pike
Gar
Walleye
Smallmouth Bass
Catfish
Largemouth Bass
Crappie

11. Phylum Chordata: Subphylum Vertebrata: Class Osteichthyes
Smallmouth Bass
Largemouth Bass

12. Phylum Chordata: Subphylum Vertebrata: Class Osteichthyes
Tuna
Eel
Bony Fish
Ray-finned fish (Marine)
Lion
Puffer
Dolphinfish
Sea Horse
Angel
Marlin
Angler fish
Tang
Clown

13. Phylum Chordata: Subphylum Vertebrata: Class Osteichthyes
Bony Fish
Lobe-finned fish
Very rare, Lungfish, (does not have lungs) uses it’s modified swim bladder which also diffuses oxygen
Thought to be extinct millions of years ago, the prehistoric Coelacanth
Natives on the island of Madagascar have been accidentally catching them in fishing nets down in the far depths for centuries
Unable to live in captivity

14. Phylum Chordata: Subphylum Vertebrata: Class Amphibia
Amphibians
“Double life”
Most live in water as larva and on land as adults
Adults have lungs, moist skin, lack scales and claws
External fertilization, eggs have no shells require moisture
Frogs & Toads (o. Anura)
Salamanders (o. Urodela)
Caecilians (o. Apoda)
Tree frog
Bullfrog
Leopard Frog
Fowler’s Toad
American Toad
External Gills!
Mudpuppy

15. Phylum Chordata: Subphylum Vertebrata: Class Amphibia
Here’s a fun fact!
Some frogs carry their eggs on their backs after until they hatch.
This is a rare photo of the Gastric Brooding Frog. It has not been seen in the wild since the 1990’s and is thought to be extinct. The eggs are retained in the mothers stomach until mature enough to crawl out!

16. Phylum Chordata: Subphylum Vertebrata: Class Reptilia
Garder
Coral snake
Anole
Reptiles
Vertebrates with dry, scaly skin, lungs, and terrestrial eggs with several membranes
4 Groups:
Lizards & Snakes
(Order Squamata)
Crocodiles & Aligators
(Order Crocodilia)
Gecko
Diamondback
Iguana
Chameleon
Alligator
Crocodile

17. Phylum Chordata: Subphylum Vertebrata: Class Reptilia
Box
Tortoise
Reptiles
Vertebrates with dry, scaly skin, lungs, and terrestrial eggs with several membranes
4 Groups:
Turtles & Tortoises
(Order Testudines)
Tuataras
(Order Sphenodonta)
Painted
Leatherback

18. Phylum Chordata: Subphylum Vertebrata: Class Reptilia
Myth Buster #1
Snakes do not “dislocate” their jaws when swallowing.
Any herpetologist will explain that their jaws can “expand” but the joints do not “dislocate” and then “relocate” afterwards.

19. Birds!
Nearly 10,000 Species!

20. Birds! Most Reptiles have 3-chambered hearts, some have 4.
Birds have 4-chambered hearts and have scales (on their legs) but are different from reptiles for 2 main reasons:
1. Birds can maintain a constant internal body temperature.
2. Birds possess the unique structures called feathers (which are actually very complex in structure)

21. Birds, not Aves…REPTILES!
Myth Buster #2
Taxonomists have debated back and forth over how to classify birds.
Depending on the year of publication one book might list them in class Aves and another in class Reptilia.
However! Herpetologists stand firm that since feathers are evolutionarily modified scales, the correct placement is in Class REPTILIA!

22. Phylum Chordata: Subphylum Vertebrata: Class Mammalia
Mammals
All mammals are characterized by 2 notable features: Hair and Mammary Glands
Mammals nourish their young with milk, breathe air, are endotherms (generate their internal body heat), and have 4-chambered hearts
Complex circulatory systems, excretory systems, and JAWS
Large brains and increased intelligence

23. Phylum Chordata: Subphylum Vertebrata: Class Mammalia
Mammals
Use Lungs for Respiration

24. Phylum Chordata: Subphylum Vertebrata: Class Mammalia
Mammals
Monotremes are mammals that lay eggs
Marsupials bear live young in an external pouch

25. Phylum Chordata: Subphylum Vertebrata: Class Mammalia
Mammals
Placental Mammals bear young internally that obtain nutrients and oxygen, and exchange waste and carbon dioxide between the mother and embryo through the placenta

26. Phylum Chordata: Subphylum Vertebrata: Class Mammalia
Elephants
Elephants are Matriarchal, the oldest female leads the pride around the African Savanna.
Elephants have large brains and great memories.
Therefore, the oldest elephants are the most important to the entire pride.

27. Phylum Chordata: Subphylum Vertebrata: Class Mammalia
Elephants
Sadly, the oldest elephants also usually have the longest tusks and are victims of poaching.
Elephants exhibit emotion and actually line up to mourn the loss of a dead relative, each paying their individual respects.