1. What Makes a Fish a Fish? Chapter 8: Marine Fishes

2. Fish are Vertebrates… 1. Backbone – called a vertebral column or spine –Dorsal row of hollow skeletal elements (usually bone) called vertebrae 2. Nerve Cord/Spinal Cord Protected by vertebrae Ends at the brain 3. Bilateral Symmetry 4. Endoskeleton

3. Yellow Perch

4. What Makes a Fish a Fish? A fish is an organism that… –is aquatic, –exchanges oxygen using gills, –is covered with scales, –and has paired fins.

5. Fish Anatomy

6. A Typical Fish

7. Background Oldest, structurally simplest vertebrates Most abundant vertebrates –At least 30,000 species Phylum: Chordata –Subphylum: Vertebrata Class: Agnatha – jawless fishes Class: Chondrichthyes – sharks, rays, ratfish Class: Osteicthyes – bony fishes

8. CharacteristicClass AgnathaClass Chondrichthyes Class Osteichthyes Skeleton…Lack Jaws Cartilaginous Movable Jaw with teeth Sharks will lose and replace teeth throughout their life Bony Body Plan…Long Cylindrical Fusiform in sharks Dorsoventrally flat in sharks and rays Diverse! Shape of tail…Lack paired fins One long body Paired fins Heterocercal tails in sharks Whip-like tails in rays with venomous spines Homocercal Fin rays usually with spines

9. CharacteristicClass AgnathaClass Chondrichthyes ClassOsteichthyes Scales…Lack scalesPlacoid scales (dermal denticles) - covered in enamel like teeth -Pointed tip that points backwardsPointed tip that points backwards - Produces rough feeling Cycloid/ Ctenoid scales Many bones Unique features… Feed by suction with the aid of a round mouth and rows of teeth Ventral mouth 5-7 gill slits Operculum – gill cover Swim bladder – gas- filled to aid buoyancy Examples:Hagfish Lamprey Sharks Skates Rays

18. Coloration

26. Movement

34. Feeding

44. Senses

48. Reproduction