1. Chordates and Fish

2. What is a chordate? Members of the KINGDOM ANIMALIA
and the PHYLUM CHORDATA
They have a dorsal, hollow nerve cord
and a notocord

3. Chordates have pharyngeal pouches (become gills)
Tail - extends beyond anus
Most chordates are vertebrates (SUBPHYLUM VERTEBRATA)

4. Chordates that are NOT vertebrates: Sea Squirts or Tunicates

6. Lancelet

7. Chordate Anatomy

8. All vertebrates are chordates.................
Consider this....
All vertebrates are chordates
But not all chordates are vertebrates.
NO WAY!!!!

9. What is a vertebrate? -Animals with a backbone (and endoskeleton)
-Have spinal cord (dorsal, hollow nerve cord)
-Front end of spinal cord develops a brain

11. 1. Members of the Phylum __________ have a dorsal hollow nerve cord.
Quick Check
1. Members of the Phylum __________ have a dorsal hollow nerve cord.
2. During development, the pharyngeal pouches will become ___________
3. All chordates belong to the animal kingdom. (T or F )
4. All chordates are vertebrates. (T or F ) 5. You are more closely related to a sea squirt than to an earthworm.
5. What are two animals that are chordates, but not vertebrates?
6. An animal with a backbone is called a _________.

12. Crash Course in Chordates - 12 minutes

13. Vertebrate Classes Jawless Fish (lamprey, hagfish)
Cartilage Fish (sharks, rays…)
Bony Fish (salmon, catfish, goldfish…)
Amphibians (frogs, salamanders…)
Reptiles (lizards, turtles…)
Birds (sparrows, hawks…)
Mammals (humans, whales, cats..)

14. What are Fish? * Anything with gills, scales, and fins…
1st Fish were jawless
Devonian Period - "Age of Fishes“
Fossil of a devonian fish with jaws and armored plates
Stethacanthus Tribute Video

15. Form & Function
1. Circulation

16. Fish have a two chambered heart – blood is passed over the gills where it picks up oxygen

17. 2. Respiration Water passes over GILLS, oxygen is added
Some fish have gill covers – OPERCULUM
Some fish have special organs to serve as lungs (Lungfish)

18. 3. Excretion Homeostasis: maintaining water balance
Salt water fish tend to lose water
Freshwater fish tend to gain water
*This is why you can’t put a salt water fish in a fresh water tank
*The salmon can do both

19. 4. The Nervous System
Response - Cerebrum - thinking, voluntary activities - Cerebellum - coordination - Medulla Oblongata - functions of internal organs
- Lateral Line System - senses vibrations

20. 1. Fish have _____________________ loop circulation.
Quick Check over Form and Function
1. Fish have _____________________ loop circulation.
Mammals and birds have ____________________ loop circulation.
2. The two chambers of the fish heart are the _______________ and ______________
3. Blood leaves the heart goes to the gills and then to the ____________ before it returns to the heart.
4. The covering of the gills is the _________________________
5. __________________________ is the maintaining of a water balance.
6. The part of the brain used for thinking and learning is the ______________________
7. The part of the brain used for balancing is the ______________________
8. The _________________ ___________ system senses vibrations.
9. Early fish did not have _________________________ What fish alive today are like that? _________________ and _______________

21. Other Fish Adaptations
A. Swim Bladder – maintains buoyancy (like a balloon)
Sharks do not have a swim bladder, if they stop swimming, they sink.

22. B. FINS

23. C. SCALES Scales cover and protect the fish
Mucus on scales help fish swim
The rings on a scale tell the fish’s age

25. 5. Reproduction
Spawning – fish lay eggs that are fertilized externally
Some fish bear live young
This 1 minute video shows a lemon shark give birth to live young.
Some sharks lay eggs.

26. Types of Reproduction Oviparous (lays eggs)
Ovoviviparous (eggs stay in mom)
Viviparous (babies get nourishment from mom. Ex. Humans, cats, some fish)

27. Salmon Video at National Geographic