FISH (and chordates)

1. FISH(and chordates)

2. Members of the ANIMAL KINGDOMand the PHYLUM CHORDATA • They have a dorsal, hollow nerve cord, a notocord, pharyngeal gill slits, and a post-anal tail at some point in life. • A few chordates are invertebrates but most are vertebrates. What is a chordate?

3. Chordate Anatomy

4. A few Chordates that are NOT vertebrates include a group know as protochordates. These include: Sea Squirts or Tunicates

6. and Lancelets

7. ---Animals with a backbone or vertebral column (endoskeleton) ----Have spinal cord - dorsal, hollow nerve cord ----Front end of spinal cord develops a brain (cephalization) ---- Closed circulatory system What is a vertebrate?

8. 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..) Vertebrate Classes

9. Fish Classification • Kingdom- Animalia • Phylum- Chordata • Sub Phylum- Vertebrata • Classes- Myxini, Cephalaspidomorphi Chondrichthyes, Osteichthyes

10. General Fish Characteristics • Gills • Backbone (vertebrae) • Paired Fins • Single Loop Circulation

11. Fish have a two chambered heart – and single loop circulation: blood is passed over the gills where it picks up oxygen, goes to the body and returns to the heart

12. Fish Respiration • Water flows over Gills as fish opens mouth and swims. • Water flows opposite direction of blood flow.

13. Fish Respiration • O2 diffuses from the water into the blood. • Gills are made of thousands of gill filaments. • Gills are covered by the Operculum.

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

15. Most fish lay eggs that are fertilized externally - called spawning • Some fish bear live young Reproduction

16. Fish Adaptations • Lateral Line System- used to detect vibrations, orient the fish in water, it is a line of cells running down the side of the fish. • Operculum- gill cover, movement of operculum allows more water to be drawn in. • Swim Bladder- a gas filled sac that helps the fish maintain buoyancy. Sharks don’t have a swim bladder! • Fins- Dorsal, Caudal, Pectoral, Pelvic, Anal.

19. Class Myxini and Cephalaspidomorphi Jawless fish: Hagfish and Lampreys

20. Types of Jawless Fish • Hagfish (class Myxini)- Ocean scavengers, not much is known about them. Hagfish Slime Video • Lamprey (class Cephalaspidomorphi) - fresh and salt water, they are parasitic and prey on other fish. * Both have cartilagenous skeletons and sucker-like mouths. Lamprey Video

21. Class Chondrichthyes Sharks and Rays • Cartilage skeletons, no bones • No operculum, must keep moving to breathe. • Have live births. • Special scales feel like sandpaper.

22. Types of Chondrichthyes • Sharks Lemon Shark Birth Video • Sharks are adapted for a predatory lifestyle. • Cartilage skeletons, no bones stiff pectoral fins (speed).

23. Types of Chondrichthyes • Rays Manta, and Sting Rays- live in shallow water, have mouths located on the underside, are fairly docile, wide flat bodies and wing-like fins that are flexible. Rays and Skates comparison

24. Class Osteichthyes Bony Fish: Salmon, Carp, Tuna

25. Types of Osteichthyes Ray Finned • Most fish are this type • Fins are supported by bony structures called Rays.

26. Types of Osteichthyes Lobe Finned • Fins are long, fleshy, muscular, supported by central core of bones. • Thought to be ancestors of amphibians. • Examples are: Coelacanth, Lungfish