Biology Slide 1 of 62 Copyright Pearson Prentice

Biology Slide 1 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Fishes Slide 2 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Fishes What Is a Fish? Fishes are aquatic vertebrates. Most fishes have paired fins, scales, and gills. Caudal fin Dorsal fin Lateral line Scales Eye Mouth Anal fin Operculum Pelvic fin Pectoral fin (gill cover) Copyright Pearson Prentice Hall Slide 3 of 62 End Show

30 -2 Fishes Evolution of Fishes The First Fishes The earliest fishes to appear in the fossil record lived about 510 million years ago. These fishes were jawless and had bodies covered with bony plates. Slide 4 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Fishes Evolution of Fishes The Arrival of Jaws and Paired Fins The evolution of jaws in fish was extremely useful. Jaws with muscles and teeth made it possible for fish to eat a wider variety of foods. Animals with jaws can also defend themselves by biting. Slide 5 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Fishes Evolution of Fishes The Rise of Modern Fishes Early jawed fishes soon disappeared, but left behind two major groups that continued to evolve and still survive today. One group—the ancestors of modern sharks and rays—evolved a skeleton made of strong, resilient cartilage. The other group evolved skeletons made of true bone. Slide 6 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Fishes Form and Function in Fishes use their gills to exchange gases by pulling oxygen-rich water in through their mouths, pumping it over their gill filaments, and pushing oxygen-poor water out through openings in the sides of the pharynx. Gills Slide 7 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Fishes Form and Function in Fishes Circulation in a Fish Gills Body muscle circulation Digestive system circulation Brain and head circulation Heart Slide 8 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Fishes Form and Function in Fishes Many bony fishes have an internal, gas-filled organ called a swim bladder that adjusts their buoyancy. Swim bladder Slide 9 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Fishes Groups of Fishes All living fishes can be classified into three groups: jawless fishes, cartilaginous fishes, and bony fishes. Slide 10 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Fishes Groups of Fishes Jawless Fishes Jawless fishes have no true teeth or jaws. Their skeletons are made of fibers and cartilage. They lack vertebrae, and keep their notochords as adults. Slide 11 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Fishes Groups of Fishes Modern jawless fishes are divided into two classes: lampreys and hagfishes. Lamprey Copyright Pearson Prentice Hall Slide 12 of 62 End Show

30 -2 Fishes Hagfish Copyright Pearson Prentice Hall Slide 13 of 62 End Show

30 -2 Fishes Groups of Fishes Sharks and Their Relatives The class Chondrichthyes contains sharks, rays, skates, sawfishes, and chimaeras. The skeletons of these fishes are built entirely of cartilage. Slide 14 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Fishes Pacific Manta Ray Slide 15 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Fishes Groups of Fishes Bony Fishes Bony fishes make up the class Osteichthyes. Their skeletons are made of bone. Almost all living bony fishes are ray-finned fishes. “Ray-finned” refers to the slender bony spines, or rays, that are connected by a thin layer of skin to form the fins. Slide 16 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Fishes Bony Fish Slide 17 of 62 Copyright Pearson Prentice Hall End Show

30 -2 Click to Launch: Continue to: - or - Slide 18 of 62 End Show Copyright Pearson Prentice Hall

30 -2 A characteristic of almost all fish is a. a notocord as an adult. b. the presence of scales. c. a skeleton made of cartilage. d. the lack of jaws. Slide 19 of 62 End Show Copyright Pearson Prentice Hall

30 -2 An example of a fish that is a filter feeder as a larva and a parasite as an adult is a a. shark. b. skate. c. lamprey. d. lungfish. Slide 20 of 62 End Show Copyright Pearson Prentice Hall

30 -2 Most members of the class containing sharks and rays are characterized by a. a cartilaginous skeleton. b. a bony skeleton. c. a single operculum over the gills. d. no swim bladder. Slide 21 of 62 End Show Copyright Pearson Prentice Hall

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