1. End Show Slide 1 of 62 Copyright Pearson Prentice Hall Biology

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

3. End Show 30-2 Fishes Slide 3 of 62 Copyright Pearson Prentice Hall What Is a Fish? What are the basic characteristics of fishes?

4. End Show 30-2 Fishes Slide 4 of 62 Copyright Pearson Prentice Hall What Is a Fish? Fishes are aquatic vertebrates. Most fishes have paired fins, scales, and gills. Anal fin Eye Mouth Dorsal fin Caudal fin Operculum (gill cover) Pelvic fin Pectoral fin Lateral lineScales

5. End Show 30-2 Fishes Slide 5 of 62 Copyright Pearson Prentice Hall Evolution of Fishes What were the important developments during the evolution of fishes?

6. End Show 30-2 Fishes Slide 6 of 62 Copyright Pearson Prentice Hall Evolution of Fishes Fishes and nonvertebrate chordates probably evolved from common invertebrate ancestors. The evolution of jaws and the evolution of paired fins were important developments during the rise of fishes.

7. End Show 30-2 Fishes Slide 7 of 62 Copyright Pearson Prentice Hall 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.

8. End Show 30-2 Fishes Slide 8 of 62 Copyright Pearson Prentice Hall Evolution of Fishes The Age of Fishes During the Devonian Period, some fishes were jawless species that had very little armor. Armored fishes became extinct at the end of the Devonian Period.

9. End Show 30-2 Fishes Slide 9 of 62 Copyright Pearson Prentice Hall 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.

10. End Show 30-2 Fishes Slide 10 of 62 Copyright Pearson Prentice Hall Evolution of Fishes Fishes evolved paired pectoral (anterior) and pelvic (posterior) fins. These fins were attached to girdles—structures of cartilage or bone that support the fins. Cartilage is a strong tissue that supports the body and is softer and more flexible than bone.

11. End Show 30-2 Fishes Slide 11 of 62 Copyright Pearson Prentice Hall Evolution of Fishes Paired fins gave fishes more control of body movement. Tail fins and powerful muscles gave fishes greater thrust when swimming.

12. End Show 30-2 Fishes Slide 12 of 62 Copyright Pearson Prentice Hall 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.

13. End Show 30-2 Fishes Slide 13 of 62 Copyright Pearson Prentice Hall How are fishes adapted for life in water? Form and Function in Fishes

14. End Show 30-2 Fishes Slide 14 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Adaptations to aquatic life include various modes of feeding, specialized structures for gas exchange, and paired fins for locomotion.

15. End Show 30-2 Fishes Slide 15 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Feeding Every mode of feeding is seen in fishes. A single fish may exhibit several modes of feeding, depending on the type of food available.

16. End Show 30-2 Fishes Slide 16 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Food passes through the mouth and esophagus, into the stomach. In the stomach, the food is partially broken down. Mouth Esophagus Stomach

17. End Show 30-2 Fishes Slide 17 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes In many fishes, the food is further processed in fingerlike pouches called pyloric ceca. The pyloric ceca secretes digestive enzymes and absorbs nutrients from the digested food. Pyloric cecum

18. End Show 30-2 Fishes Slide 18 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes The liver and pancreas add enzymes and other digestive chemicals to the food as it moves through the digestive tract. Liver Pancreas

19. End Show 30-2 Fishes Slide 19 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes The intestine completes the process of digestion and nutrient absorption. Intestine Only show “Intestine” label on this slide.

20. End Show 30-2 Fishes Slide 20 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Undigested material is eliminated through the anus. Anus

21. End Show 30-2 Fishes Slide 21 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Respiration Most fishes exchange gases using gills located on either side of the pharynx. Gills

22. End Show 30-2 Fishes Slide 22 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes 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

23. End Show 30-2 Fishes Slide 23 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Circulation Fishes have closed circulatory systems with a heart that pumps blood around the body in a single loop from the heart to the gills, from the gills to the rest of the body, and then back to the heart.

24. End Show 30-2 Fishes Slide 24 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes In most fishes, the heart has four parts: the sinus venosus the atrium the ventricle the bulbus arteriosis

25. End Show 30-2 Fishes Slide 25 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Body muscle circulation Brain and head circulation Heart Digestive system circulation Gills Circulation in a Fish

26. End Show 30-2 Fishes Slide 26 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Oxygen-poor blood from the veins collects in the sinus venosus. Sinus Venosus

27. End Show 30-2 Fishes Slide 27 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes The atrium is a large muscular chamber that serves as a one-way compartment for blood that is about to enter the ventricle. Blood enters the atrium and flows to the ventricle. Atrium

28. End Show 30-2 Fishes Slide 28 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes The ventricle is a thick- walled, muscular chamber that is the actual pumping portion of the heart. The ventricle pumps blood into the bulbus arteriosus. Ventricle

29. End Show 30-2 Fishes Slide 29 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes The bulbus arteriosus moves blood into the ventral aorta and toward the gills. Bulbus arteriosus

30. End Show 30-2 Fishes Slide 30 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Excretion Fishes eliminate nitrogenous wastes in the form of ammonia. Some wastes diffuse through the gills into the surrounding water.

31. End Show 30-2 Fishes Slide 31 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Others wastes are removed by kidneys. The kidneys of marine fishes concentrate wastes and return water to the body. Kidney

32. End Show 30-2 Fishes Slide 32 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes The kidneys of freshwater fishes pump out dilute urine. Kidney

33. End Show 30-2 Fishes Slide 33 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Response Fishes have well-developed nervous systems organized around a brain. Brain

34. End Show 30-2 Fishes Slide 34 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes The olfactory bulbs are involved with the sense of smell, or olfaction. Olfactory bulb

35. End Show 30-2 Fishes Slide 35 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes In most vertebrates, the cerebrum is responsible for all the voluntary activities of the body. In fishes, however, the cerebrum primarily processes the sense of smell. Cerebrum

36. End Show 30-2 Fishes Slide 36 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes The optic lobes process information from the eyes. Optic lobe

37. End Show 30-2 Fishes Slide 37 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes The cerebellum coordinates body movements. Cerebellum

38. End Show 30-2 Fishes Slide 38 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes The medulla oblongata controls the functioning of many internal organs. Medulla oblongata

39. End Show 30-2 Fishes Slide 39 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Almost all fishes that are active in daylight have well- developed eyes and color vision. Many fishes have extraordinary senses of taste and smell. Most fishes have ears but may not hear sounds well.

40. End Show 30-2 Fishes Slide 40 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Fishes use the lateral line system to sense the motion of other fishes or prey swimming nearby. Some fishes can detect low levels of electric current.

41. End Show 30-2 Fishes Slide 41 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Many bony fishes have an internal, gas-filled organ called a swim bladder that adjusts their buoyancy. Swim bladder

42. End Show 30-2 Fishes Slide 42 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Movement Most fishes move by contracting paired sets of muscles on either side of the backbone. A series of S-shaped curves move down the fish’s body. The force and the action of the fins propels the fish forward. The fins of fishes are used to keep on course and adjust direction.

43. End Show 30-2 Fishes Slide 43 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes Reproduction The eggs of fishes are fertilized either externally or internally, depending on the species. Fishes whose embryos in the eggs develop and hatch outside the mother's body are oviparous. The embryos of oviparous fishes obtain food from the yolk in the egg.

44. End Show 30-2 Fishes Slide 44 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes In ovoviviparous species, the eggs stay in the mother's body after internal fertilization. Each embryo develops inside its egg, using the yolk for nourishment. The young are “born alive” like most mammals.

45. End Show 30-2 Fishes Slide 45 of 62 Copyright Pearson Prentice Hall Form and Function in Fishes In viviparous animals, the embryos stay in the mother's body after internal fertilization. These embryos obtain the substances they need from the mother's body (not from material in an egg). The young of viviparous species are “born alive.”

46. End Show 30-2 Fishes Slide 46 of 62 Copyright Pearson Prentice Hall Groups of Fishes What are the three main groups of fishes?

47. End Show 30-2 Fishes Slide 47 of 62 Copyright Pearson Prentice Hall Groups of Fishes All living fishes can be classified into three groups: jawless fishes, cartilaginous fishes, and bony fishes. Groups of Fishes

48. End Show 30-2 Fishes Slide 48 of 62 Copyright Pearson Prentice Hall 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. Groups of Fishes

49. End Show 30-2 Fishes Slide 49 of 62 Copyright Pearson Prentice Hall Modern jawless fishes are divided into two classes: lampreys and hagfishes. Lamprey Groups of Fishes

50. End Show 30-2 Fishes Slide 50 of 62 Copyright Pearson Prentice Hall Lampreys are typically filter feeders as larvae and parasites as adults. Adult lampreys attach themselves to fishes, whales, and dolphins. They scrape away at the skin with small toothlike structures. The lamprey sucks up the tissues and body fluids of its host. Groups of Fishes

51. End Show 30-2 Fishes Slide 51 of 62 Copyright Pearson Prentice Hall Hagfishes have pinkish gray, wormlike bodies and four or six short tentacles around their mouths. They lack eyes, but have light-detecting sensors scattered around their bodies. They feed on dead and dying fish by using a toothed tongue to scrape a hole into the fish’s side. Groups of Fishes

52. End Show 30-2 Fishes Slide 52 of 62 Copyright Pearson Prentice Hall Sharks and Their Relatives The class Chondrichthyes contains sharks, rays, skates, sawfishes, and chimaeras. The skeletons of these fishes are built entirely of cartilage. Many sharks have thousands of teeth arranged in several rows. Most species of sharks do not attack people. Groups of Fishes

53. End Show 30-2 Fishes Slide 53 of 62 Copyright Pearson Prentice Hall Some skates and rays feed on bottom-dwelling invertebrates. The largest rays eat floating plankton. Skates and rays glide through the sea with their large, winglike pectoral fins. Many skates and rays cover themselves with sand and rest on the ocean floor. Groups of Fishes

54. End Show 30-2 Fishes Slide 54 of 62 Copyright Pearson Prentice Hall 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. Groups of Fishes

55. End Show 30-2 Fishes Slide 55 of 62 Copyright Pearson Prentice Hall Only seven living species of bony fishes are not classified as ray-finned fishes. These are the lobe-finned fishes, a subclass that includes lungfishes and the coelacanth. The fleshy fins of lobe-finned fishes have support bones. Some of these bones are jointed. Groups of Fishes

56. End Show 30-2 Fishes Slide 56 of 62 Copyright Pearson Prentice Hall Ecology of Fishes Some fishes spend most of their lives in the ocean but migrate to fresh water to breed. These fish are called anadromous. Salmon are anadromous.

57. End Show - or - Continue to: Click to Launch: Slide 57 of 62 Copyright Pearson Prentice Hall 30-2

58. End Show Slide 58 of 62 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.

59. End Show Slide 59 of 62 Copyright Pearson Prentice Hall 30-2 Fishes whose eggs hatch outside the mother’s body are a.ovoviviparous. b.oviparous. c.viviparous. d.parous.

60. End Show Slide 60 of 62 Copyright Pearson Prentice Hall 30-2 Salmon are anadromous fishes that a.spend their lives in the sea. b.spend their lives in rivers or streams. c.migrate to the sea in order to spawn. d.migrate to rivers and streams to spawn.

61. End Show Slide 61 of 62 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.

62. End Show Slide 62 of 62 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.

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