1. FISHES Chapter 30

2. Learning Targets 30.2 Identify the characteristics of fishes Summarize the evolution of fishes. Explain how fishes are adapted for life in water. Describe the three main groups of fishes Identify the characteristics of fishes Summarize the evolution of fishes. Explain how fishes are adapted for life in water. Describe the three main groups of fishes

3. Fishes Fishes are aquatic vertebrates that are characterized by Paired fins Scales Gills Fishes are so varied, however, that for almost every general characteristic there are exceptions. Example: Catfish don’t have scales Fishes are aquatic vertebrates that are characterized by Paired fins Scales Gills Fishes are so varied, however, that for almost every general characteristic there are exceptions. Example: Catfish don’t have scales

5. Evolution of Fishes They did not arise directly from tunicates or lancelets. Fishes and non-vertebrate chordates evolved from common invertebrate ancestors. The evolution of jaws and the evolution of paired fins were important developments during the rise of fishes They did not arise directly from tunicates or lancelets. Fishes and non-vertebrate chordates evolved from common invertebrate ancestors. The evolution of jaws and the evolution of paired fins were important developments during the rise of fishes

6. Evolution of Fishes The first fishes were thought to be jawless creatures whose bodies were armored with bony plates The Arrival of Jaws and Paired Fins Jaws make it possible for vertebrate to nibble on plants and to munch on other animals Animals with jaws are able to eat a wide variety of food They are able to defend themselves by biting These adaptations alone have increased survival The first fishes were thought to be jawless creatures whose bodies were armored with bony plates The Arrival of Jaws and Paired Fins Jaws make it possible for vertebrate to nibble on plants and to munch on other animals Animals with jaws are able to eat a wide variety of food They are able to defend themselves by biting These adaptations alone have increased survival

7. Form and Function in Fishes Adaptations to aquatic life include: Various modes of feeding Specialized structures for gas exchange Paired fins for locomotion Adaptations to aquatic life include: Various modes of feeding Specialized structures for gas exchange Paired fins for locomotion

8. Feeding and Respiration in Fishes Feeding: Every mode of feeding is displayed Respiration: Most fishes exchange gases using gills that are located on either side of the pharynx Feeding: Every mode of feeding is displayed Respiration: Most fishes exchange gases using gills that are located on either side of the pharynx

10. Circulation in Fishes Fishes have a closed circulatory system The system has: Heart It pumps blood around the body in a single loop Single Loop Circulatory System Single loop from the heart to the gills From the gills to the rest of the body Then back to the heart Fishes have a closed circulatory system The system has: Heart It pumps blood around the body in a single loop Single Loop Circulatory System Single loop from the heart to the gills From the gills to the rest of the body Then back to the heart

12. Excretion Like many other aquatic animals, most fishes get rid of nitrogenous waste in the form of ammonia. Some of the waste will diffuse through the gills into the surrounding water Others will remove waste by kidneys These are excretory organs that filter wastes from the blood. Like many other aquatic animals, most fishes get rid of nitrogenous waste in the form of ammonia. Some of the waste will diffuse through the gills into the surrounding water Others will remove waste by kidneys These are excretory organs that filter wastes from the blood.

13. Excretion cont. Kidneys help to control the amount of water that is in their bodies Fishes in saltwater tend to lose water by osmosis and excrete concentrated wastes In contrast, freshwater fishes pump out plenty of dilute urine. Kidneys help to control the amount of water that is in their bodies Fishes in saltwater tend to lose water by osmosis and excrete concentrated wastes In contrast, freshwater fishes pump out plenty of dilute urine.

14. Response Fishes have well developed nervous systems organized around a brain with many parts The cerebrum is responsible for all voluntary activities in the body The cerebrum of fish primarily processes the sense of smell Fishes have well developed nervous systems organized around a brain with many parts The cerebrum is responsible for all voluntary activities in the body The cerebrum of fish primarily processes the sense of smell

15. Fish Brain

16. Response The optic lobe processes information from the eyes The cerebellum coordinates body movements The medulla oblongata controls the functioning of many internal organs In addition, fishes use a lateral line system to sense motion of other fishes or prey The optic lobe processes information from the eyes The cerebellum coordinates body movements The medulla oblongata controls the functioning of many internal organs In addition, fishes use a lateral line system to sense motion of other fishes or prey

17. Fish Brain

18. Movement Fishes move by alternately contradicting paired sets of muscles on either side of their backbone. Many bony fishes have an internal, gas filled organ called a swim bladder It adjusts the fishes buoyancy Fishes move by alternately contradicting paired sets of muscles on either side of their backbone. Many bony fishes have an internal, gas filled organ called a swim bladder It adjusts the fishes buoyancy

19. Reproduction The eggs of fishes are fertilized either internally or externally Types of Development: Oviparous Ovoviviparous Viviparous The eggs of fishes are fertilized either internally or externally Types of Development: Oviparous Ovoviviparous Viviparous

20. Reproduction Oviparous: Eggs hatch outside the mother’s body Example: Salmon, fish, and crocodiles Ovoviviparous: Eggs stay in the mother’s body and the young are then born alive Obtain the nutrients needed from the egg yolk Example: Insects, fish, snakes, and lizards Viviparous: The young are born alive The young obtain nutrients directly from the mother’s body Example: Humans, snakes Oviparous: Eggs hatch outside the mother’s body Example: Salmon, fish, and crocodiles Ovoviviparous: Eggs stay in the mother’s body and the young are then born alive Obtain the nutrients needed from the egg yolk Example: Insects, fish, snakes, and lizards Viviparous: The young are born alive The young obtain nutrients directly from the mother’s body Example: Humans, snakes

21. Groups of Fishes

22. When you consider their basic internal structure, all living fishes can be classified into three groups: Jawless Fishes Cartilaginous Fishes Bony Fishes When you consider their basic internal structure, all living fishes can be classified into three groups: Jawless Fishes Cartilaginous Fishes Bony Fishes

23. Jawless Fishes Have no teeth or jaws Skeleton are made of fibers and cartilage They lack vertebrae and keep their notochords as adults Modern jawless fishes are divided into two groups: Lampreys Hagfishes Have no teeth or jaws Skeleton are made of fibers and cartilage They lack vertebrae and keep their notochords as adults Modern jawless fishes are divided into two groups: Lampreys Hagfishes

24. Lamprey Hagfish

26. Sharks and their Relatives The class: Chondrichthyes Contain: Sharks, Rays, Skates, Sawfishes and Chimaeras The skeletons of these fishes are built entirely of cartilage….NOT bone The class: Chondrichthyes Contain: Sharks, Rays, Skates, Sawfishes and Chimaeras The skeletons of these fishes are built entirely of cartilage….NOT bone

30. Bony Fishes The class: Osteichthyes Contain: Combtooth Blenny, Emperor Angelfish, Flying Fish, Peacock Flounder, Leafy Sea Dragon Examples: Almost all living bony fishes belong to a huge group called ray-finned fishes The skeletons of these fishes are made of hard, calcified tissue called bone The class: Osteichthyes Contain: Combtooth Blenny, Emperor Angelfish, Flying Fish, Peacock Flounder, Leafy Sea Dragon Examples: Almost all living bony fishes belong to a huge group called ray-finned fishes The skeletons of these fishes are made of hard, calcified tissue called bone

31. The End!

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