Table of Contents – pages iii

2. Table of Contents – pages iii Unit 1:What is Biology? Unit 2:Ecology Unit 3:The Life of a Cell Unit 4:Genetics Unit 5:Change Through Time Unit 6:Viruses, Bacteria, Protists, and Fungi Unit 7:Plants Unit 8:Invertebrates Unit 9:Vertebrates Unit 10:The Human Body

3. Table of Contents – pages vii-xiii Unit 1: What is Biology? Chapter 1:Biology: The Study of Life Unit 2: Ecology Chapter 2:Principles of Ecology Chapter 3:Communities and Biomes Chapter 4:Population Biology Chapter 5:Biological Diversity and Conservation Unit 3:The Life of a Cell Chapter 6:The Chemistry of Life Chapter 7:A View of the Cell Chapter 8:Cellular Transport and the Cell Cycle Chapter 9:Energy in a Cell

4. Unit 4: Genetics Chapter 10:Mendel and Meiosis Chapter 11:DNA and Genes Chapter 12:Patterns of Heredity and Human Genetics Chapter 13:Genetic Technology Unit 5: Change Through Time Chapter 14:The History of Life Chapter 15:The Theory of Evolution Chapter 16:Primate Evolution Chapter 17:Organizing Life’s Diversity Table of Contents – pages vii-xiii

5. Unit 6: Viruses, Bacteria, Protists, and Fungi Chapter 18:Viruses and Bacteria Chapter 19:Protists Chapter 20:Fungi Unit 7: Plants Chapter 21:What Is a Plant? Chapter 22:The Diversity of Plants Chapter 23:Plant Structure and Function Chapter 24:Reproduction in Plants Table of Contents – pages vii-xiii

6. Table of Contents – pages vii-xiii Unit 8: Invertebrates Chapter 25:What Is an Animal? Chapter 26:Sponges, Cnidarians, Flatworms, and Roundworms Chapter 27:Mollusks and Segmented Worms Chapter 28:Arthropods Chapter 29:Echinoderms and Invertebrate Chordates

7. Table of Contents – pages vii-xiii Unit 9: Vertebrates Chapter 30:Fishes and Amphibians Chapter 31:Reptiles and Birds Chapter 32:Mammals Chapter 33:Animal Behavior Unit 10: The Human Body Chapter 34:Protection, Support, and Locomotion Chapter 35:The Digestive and Endocrine Systems Chapter 36:The Nervous System Chapter 37:Respiration, Circulation, and Excretion Chapter 38:Reproduction and Development Chapter 39:Immunity from Disease

8. Unit Overview – pages 790-791 Vertebrates Fishes and Amphibians Reptiles and Birds Mammals Animal Behavior

9. Chapter Contents – page xii Chapter 30Fishes and Amphibians 30.1:Fishes 30.1:Section Check 30.2:Amphibians 30.2:Section Check Chapter 30Summary Chapter 30Assessment

10. Chapter Intro-page 792 What You’ll Learn You will compare and contrast the adaptations of the different groups of fishes and amphibians. You will learn about the origin of modern fishes and amphibians.

11. 30.1 Section Objectives – page 793 Section Objectives: • Relate the structural adaptations of fishes to their environments. • Compare and contrast the characteristics of the different groups of fishes. • Interpret the phylogeny of fishes.

12. Section 30.1 Summary – pages 793-802 What is a fish? • Fishes, like all vertebrates, are classified in the phylum Chordata. • Fishes belong to the subphylum Vertebrata.

13. Section 30.1 Summary – pages 793-802 What is a fish? • In addition to fishes, subphylum Vertebrata includes amphibians, reptiles, birds, and mammals.

14. Section 30.1 Summary – pages 793-802 What is a fish? • In vertebrates, the embryo’s notochord is replaced by a backbone in adult animals. • All vertebrates are bilaterally symmetrical, coelomates that have endoskeletons, closed circulatory systems, nervous systems with complex brains and sense organs, and efficient respiratory systems.

15. Section 30.1 Summary – pages 793-802 Classes of fishes Fishes Organisms Characteristics Class Jawless, cartilaginous skeleton, gills Myxini Hagfishes Jawless, cartilaginous skeleton, gills Lampreys Cephalaspidomorphi Jaws, cartilaginous skeleton, paired fins, gills, scales, internal fertilization Chondrichthyes Sharks, skates, rays Jaws, bony skeleton, paired fins, gills, scales, swim bladder Lobe-finned fishes, ray-finned fishes Osteichthyes

16. Section 30.1 Summary – pages 793-802 Fishes breathe using gills • Fishes have gills made up of feathery gill filaments that contain tiny blood vessels. Gill Filaments

17. Section 30.1 Summary – pages 793-802 Fishes breathe using gills • As a fish takes water in through its mouth, water passes over the gills and then out through slits at the side of the fish. Gill Filaments Capillary networks in filament Water Gill filaments Artery Vein Water

18. Section 30.1 Summary – pages 793-802 Fishes breathe using gills • Oxygen and carbon dioxide are exchanged through the capillaries in the gill filaments. Gill Filaments Capillary networks in filament Water Gill filaments Artery Vein Water

19. Section 30.1 Summary – pages 793-802 Fishes have two-chambered hearts

20. Section 30.1 Summary – pages 793-802 Fishes reproduce sexually • Although the method may vary, all fishes reproduce sexually. • Fertilization and development is external in most fishes. • Eggs and sperm can be released directly into the water, or deposited in more protected areas, such as on floating aquatic plants.

21. Section 30.1 Summary – pages 793-802 Fishes reproduce sexually • Cartilaginous fishes have internal fertilization. • Skates deposit fertilized eggs on the ocean floor. • Some female sharks and rays carry developing young inside their bodies.

22. Section 30.1 Summary – pages 793-802 Fishes reproduce sexually • Most bony fishes have external fertilization and development. • This type of external reproduction in fishes and some other animals is called spawning. Salmon spawning

23. Section 30.1 Summary – pages 793-802 Fishes reproduce sexually • In some bony fishes, such as guppies and mollies, fertilization and development is internal. • Most fishes that produce millions of eggs provide no care for their offspring after spawning. • Some fishes, such as the mouth-brooding cichlids, stay with their young after they hatch.

24. Section 30.1 Summary – pages 793-802 Most fishes have paired fins • Fishes in the classes Chondrichthyes and Osteichthyes have paired fins. • Fins are fan-shaped membranes that are used for balance, swimming, and steering.

25. Section 30.1 Summary – pages 793-802 Most fishes have paired fins • Fins are attached to and supported by the endoskeleton and are important in locomotion.

26. Section 30.1 Summary – pages 793-802 Most fishes have paired fins • The paired fins of fishes foreshadowed the development of limbs for movement on land and ultimately of wings for flying. Dorsal fins Pectoral fin Anal fin Caudal fin Pelvic fins

27. Section 30.1 Summary – pages 793-802 Fishes have developed sensory systems • Cartilaginous and bony fishes have an adaptation called the lateral line system that enables them to sense objects and changes in their environment. Lateral line Gelatin-like fluid Receptor cells Nerve

28. Section 30.1 Summary – pages 793-802 Fishes have developed sensory systems • The lateral line system is a line of fluid-filled canals running along the sides of a fish that enable it to detect movement and vibrations in the water. Lateral line Gelatin-like fluid Receptor cells Nerve

29. Section 30.1 Summary – pages 793-802 Fishes have developed sensory systems • Fishes have eyes that allow them to see objects and contrasts between light and dark in the water as well.

30. Section 30.1 Summary – pages 793-802 Fishes have developed sensory systems • Some fishes that live in areas of the ocean where there is no light may have reduced, almost nonfunctional eyes.

31. Section 30.1 Summary – pages 793-802 Fishes have developed sensory systems • Some fishes also have an extremely sensitive sense of smell and can detect small amounts of chemicals in the water. • Sharks can follow a trail of blood through the water for several hundred meters.

32. Section 30.1 Summary – pages 793-802 Most fishes have scales • Scales are thin bony plates formed from the skin. • Scales can be toothlike, diamond-shaped, cone-shaped, or round. Shark scales are similar to teeth found in other vertebrates.

33. Section 30.1 Summary – pages 793-802 Jaws evolved in fishes Gill arches Gill slits Jawless, filter-feeding fish Jaws Skull Gill slits Gill arches Fish with jaws Beginning of jaw formation • The advantage of jaws is that they enable an animal to grasp and crush its prey with great force.

34. Section 30.1 Summary – pages 793-802 Jaws evolved in fishes Gill arches Gill slits Jawless, filter-feeding fish Jaws Skull Gill slits Gill arches Fish with jaws Beginning of jaw formation • Jaws also allowed early fishes to prey on a greater variety of organisms.

35. Section 30.1 Summary – pages 793-802 Jaws evolved in fishes • Sharks have up to 20 rows of teeth that are continually replaced. • Their teeth point backwards to prevent prey from escaping once caught.

36. Section 30.1 Summary – pages 793-802 Jaws evolved in fishes • Sharks are among the most streamlined of all fishes and are well adapted for life as predators.

37. Section 30.1 Summary – pages 793-802 Most fishes have bony skeletons • Bony fishes, a successful and widely distributed class, differ greatly in habitat, size, feeding behavior, and shape.

38. Section 30.1 Summary – pages 793-802 Most fishes have bony skeletons • All bony fishes have skeletons made of bone rather than cartilage as found in other classes of fishes. • Bone is the hard, mineralized, living tissue that makes up the endoskeleton of most vertebrates.

39. Section 30.1 Summary – pages 793-802 Bony fishes have separate vertebrae that provide flexibility • The evolution of a backbone composed of separate, hard segments called vertebrae was significant in providing the major support structure of the vertebrate skeleton. • Separate vertebrae provide great flexibility.

40. Section 30.1 Summary – pages 793-802 Bony fishes have separate vertebrae that provide flexibility A tuna keeps its body rigid, moving only its powerful tail. Fishes that use this method move faster than all others. A mackerel flexes the posterior end of its body to accentuate the tail -fin movement. An eel moves its entire body in an S-shaped pattern.

41. Section 30.1 Summary – pages 793-802 Bony Fish

42. Section 30.1 Summary – pages 793-802 Diversity of fishes • Fishes range in size from the tiny dwarf goby that is less than 1 cm long, to the huge whale shark that can reach a length of about 15 m—the length of two school buses. Whale shark

43. Section 30.1 Summary – pages 793-802 Agnathans are jawless fishes • Lampreys and hagfishes belong to the superclass Agnatha. Lamprey • The skeletons of agnathans, as well as of sharks and their relatives, are made of a tough, flexible material called cartilage.

44. Section 30.1 Summary – pages 793-802 Agnathans are jawless fishes • A hagfish has a toothed mouth and feeds on dead or dying fishes. • It can drill a hole into a fish and suck out the blood and insides. • Parasitic lampreys use their suckerlike mouths to attack other fishes. • They use their sharp teeth to scrape away the flesh and then suck out the prey’s blood.

45. Section 30.1 Summary – pages 793-802 Sharks and rays are cartilaginous fishes • Sharks, skates, and rays belong to the class Chondrichthyes. • These fishes, like agnathans, possess skeletons composed entirely of cartilage. • Sharks are perhaps the most well-known predators of the oceans.

46. Section 30.1 Summary – pages 793-802 Sharks and rays are cartilaginous fishes • Like sharks, most rays are predators and feed on or near the ocean floor. • Rays have flat bodies and broad pectoral fins on their sides.

47. Section 30.1 Summary – pages 793-802 Sharks and rays are cartilaginous fishes • By slowly flapping their fins up and down, rays can glide as they search for mollusks and crustaceans along the ocean floor.

48. Section 30.1 Summary – pages 793-802 Subclasses of bony fishes • Scientists recognize two subclasses of bony fishes—the lobe-finned fishes, including lungfishes, and the ray-finned fishes. • The lobe-finned fishes are represented by seven living species: six species of lungfishes, which have both gills and lungs, and the coelacanth.

49. Section 30.1 Summary – pages 793-802 Subclasses of bony fishes • In the ray-finned fishes, such as catfish, perch, salmon, and cod, fins are fan-shaped membranes supported by stiff spines called rays. Perch

50. Section 30.1 Summary – pages 793-802 Origins of Fishes • Scientists have identified fossils of fishes that existed during the late Cambrian Period, 500 million years ago. • At this time, ostracoderms (OHS trah koh durmz), early jawless fishes, were the dominant vertebrates on Earth.