1. Chapter 16 Table of Contents Section 1 Fishes: The First Vertebrates
Fishes, Amphibians, and Reptiles
Chapter 16
Table of Contents
Section 1 Fishes: The First Vertebrates
Section 2 Amphibians
Section 3 Reptiles

2. Section 1 Fishes: The First Vertebrates
Chapter 16
Bellringer
What are some of the physical characteristics shared by dinosaurs and people?
Write your response in your science journal.

3. Chapter 16 Objectives List the four common body parts of chordates.
Section 1 Fishes: The First Vertebrates
Chapter 16
Objectives
List the four common body parts of chordates.
Describe the two main characteristics of vertebrates.
Explain the difference between an ectotherm and an endotherm.
Describe four traits that fishes share.
Describe the three classes of living fishes, and give an example of each.

4. Chapter 16 Chordates * are called vertebrates.
Section 1 Fishes: The First Vertebrates
Chapter 16
Chordates
* are called vertebrates.
Vertebrates belong to the phylum chordata.
While vertebrates make up the largest group of chordates, some chordates, such as lancelets and tunicates, do not have a backbone.
The four particular body parts shared by chordates are illustrated on the next slide.

5. Section 1 Fishes: The First Vertebrates
Chapter 16

6. Vertebrate Characteristics
Section 1 Fishes: The First Vertebrates
Chapter 16
Vertebrate Characteristics
Fishes, amphibians, reptiles, birds, and mammals are vertebrates.
* called vertebrae.
Vertebrates have a well-developed head protected by a skull. The skull can be made of either bone or cartilage.

7. Are Vertebrates Warm or Cold?
Section 1 Fishes: The First Vertebrates
Chapter 16
Are Vertebrates Warm or Cold?
All vertebrates need to live at the proper temperature. Animals have different ways to keep their body at the right temperature.
Staying Warm An Endotherm is an animal that *
Birds and mammals are endotherms. These animals are sometimes called warmblooded.

8. Are Vertebrates Warm or Cold? continued
Section 1 Fishes: The First Vertebrates
Chapter 16
Are Vertebrates Warm or Cold? continued
Cold Blood? An ectotherm is an organism that needs sources of heat outside of itself. Their body temperature changes as the temperature of the environment changes.
Nearly all amphibians, reptiles, and fishes are ectotherms. These animals are sometimes called coldblooded.

9. Fish Characteristics, continued
Section 1 Fishes: The First Vertebrates
Chapter 16
Fish Characteristics, continued
Making Sense of the World Fishes have a brain that keeps track of information coming in from the senses.
Most fishes also have a lateral line system. The lateral line is a row or rows of tiny sense organs on the side of fishes that detect water vibration.
Underwater Breathing Fishes use their gills to breathe. A gill is *

10. Chapter 16 Fish Characteristics
Section 1 Fishes: The First Vertebrates
Chapter 16
Fish Characteristics

11. Fish Characteristics, continued
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Fish Characteristics, continued
Making More Fishes Most fishes reproduce by external reproduction. *
Some species of fishes have internal fertilization. The male deposits sperm inside the female.
Most females then lay eggs with embryos inside of them. In some species, the embryos develop inside the female.

12. Chapter 16 Kinds of Fishes
Section 1 Fishes: The First Vertebrates
Chapter 16
Kinds of Fishes
There are five different classes of fishes. Two of these classes are now extinct.
The three classes of fishes that are still alive today are *

13. Kinds of Fishes, continued
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Kinds of Fishes, continued
Jawless Fishes The two kinds of modern jawless fishes are *
Hagfish and lampreys are eel-like. They have smooth slimy skin and a round, jawless mouth.
Jawless fish have a *

14. Kinds of Fishes, continued
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Kinds of Fishes, continued
Cartilaginous Fishes In most vertebrates, soft cartilage in the embryo is slowly replaced by bone. But in sharks, skates, and rays, the skeleton never changes to bone. So, they are called cartilaginous fishes.
Cartilaginous fishes have fully functional jaws.
Cartilaginous fishes store a lot of oil in their livers to help them float.

15. Kinds of Fishes, continued
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Kinds of Fishes, continued
Bony Fishes The largest class of fishes is the bony fishes. These fishes have a skeleton made of bone and a body made of bony scales.
Bony fishes have a swim bladder. A swim bladder is *

16. Kinds of Fishes, continued
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Kinds of Fishes, continued
There are two groups of bony fishes. Ray-finned fishes have pairs of fins supported by thin rays of bone.
Lobe-finned fishes have fins that are muscular and thick.

17. Section 2 Amphibians
Chapter 16
Bellringer
Name an advantage and a disadvantage of the thin, moist skin of amphibians.
Write your answers in your science journal.

18. Chapter 16 Objectives Explain how amphibians breathe.
Section 2 Amphibians
Chapter 16
Objectives
Explain how amphibians breathe.
Describe amphibian metamorphosis.
Describe the three groups of amphibians, and give an example of each.
Explain why amphibians are ecological indicators.

19. Section 2 Amphibians
Chapter 16
Moving to Land
Amphibians are animals that can live in water and have lungs and legs.
A lung is a *
Most of today’s amphibians are frogs or salamanders.
Fossils have been found of amphibians that looked very different––like a cross between a fish and salamander and up to 10 m long.

20. Characteristics of Amphibians
Section 2 Amphibians
Chapter 16
Characteristics of Amphibians
Amphibian means”double life.” Most amphibians live part of their lives in water and part of their lives on land.
Embryos must develop in water. The eggs do not have a shell or membrane that prevents water loss, so the eggs would dry up on land. Adults can live on land.
Amphibians are *

21. Characteristics of Amphibians, continued
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Characteristics of Amphibians, continued
Thin Skin Amphibian skin is thin, smooth, and moist. The skin is so thin that amphibians *
Amphibians can also lose water through their skin and become dehydrated. Their thin skin is one reason amphibians live in water or damp habitats.
Amphibians can breathe by gulping air. Many also absorb oxygen through their skin.

22. Characteristics of Amphibians, continued
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Characteristics of Amphibians, continued
Leading a Double Life Most amphibians change form as they grow.
A tadpole *
As a tadpole grows, it develops limbs and lungs and loses its tail and gills.
This change from an immature form to an adult form is called metamorphosis.

23. Section 2 Amphibians
Chapter 16

24. Chapter 16 Kinds of Amphibians
Section 2 Amphibians
Chapter 16
Kinds of Amphibians
Caecilians Caecilians live in tropical areas of Asia, Africa, and South America. They look like earthworms or snakes, but they have the thin, moist skin of amphibians.
Salamanders As adults, most salamanders live under stones and logs in the woods of North America. They have long tails and four strong legs.
Salamanders do not develop as tadpoles. But most do lose gills and grow lungs during development.

25. Kinds of Amphibians, continued
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Kinds of Amphibians, continued
Frogs and Toads About 90% of all amphibians are frogs or toads. They live all over the world, except in very cold places.
Frogs and Toads are highly adapted for life on land. Adults have strong leg muscles for jumping
They have well-developed *.

26. Kinds of Amphibians, continued
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Kinds of Amphibians, continued
Singing Frogs Frogs force air from their lungs over their vocal cords to make sound.
A thin-walled sac of skin called the vocal sac surrounds the vocal cords and increases the volume of the songs.
Frogs sing songs to communicate messages about attracting mates and marking territories.

27. Amphibians as Ecological Indicators
Section 2 Amphibians
Chapter 16
Amphibians as Ecological Indicators
Unhealthy amphibians can be an early sign of changes in an environment.
Amphibians are ecological indicators because they are very sensitive to changes in the environment. Their thin skin absorbs any chemicals in the water or air.

28. Section 3 Reptiles
Chapter 16
Bellringer
List three adjectives you associate with reptiles
Record your list in in your science journal.

29. Section 3 Reptiles
Chapter 16
Objectives
Explain the characteristics that allow reptiles to live on land.
Describe the characteristics of an amniotic egg.
Name the four groups of modern reptiles, and give an example of each.

30. Chapter 16 Living on the Land
Section 3 Reptiles
Chapter 16
Living on the Land
Reptiles have many characteristics that make them well suited for life on land.
Many reptiles are now extinct. Extinct species include dinosaurs, reptiles that could swim, others that could swim, and many that were similar to reptiles that are alive today.

31. Characteristics of Reptiles
Section 3 Reptiles
Chapter 16
Characteristics of Reptiles
Reptiles are well adapted for life on land.
Thick Skin Reptiles have thick skin that forms a watertight layer that keeps cells from losing water.
Body Temperature Nearly all reptiles are ectotherms. They are active when it is warm outside, and they slow down when it is cool. They do not live in very cold environments.

32. Characteristics of Reptiles, continued
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Characteristics of Reptiles, continued
The Amazing Amniotic Egg * an amniotic egg. Reptiles, birds, and mammals have amniotic eggs.
Reptiles eggs also have a shell. The shell *
A reptile’s eggs can be laid under rocks, in the ground, or even in the desert.

33. Section 3 Reptiles
Chapter 16

34. Chapter 16 Kinds of Reptiles
Section 3 Reptiles
Chapter 16
Kinds of Reptiles
Turtles and Tortoises Generally, tortoises live on land, and turtles spend all or much of their lives in the water. However, even sea turtles come on land to lay their eggs.
The trait that makes turtles and tortoises so unique is their shell. The shell gives them *

35. Kinds of Reptiles, continued
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Kinds of Reptiles, continued
Crocodiles and Alligators Crocodiles and alligators spend most of their time in the water. Because their eyes and nostrils are on the top of their flat heads, they can hide with most of their body under water.

36. Kinds of Reptiles, continued
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Kinds of Reptiles, continued
Snakes and Lizards Today, the most common reptiles are snakes and lizards.
Snakes have many adaptations for hunting. They can “taste” if their prey is nearby.
Some snakes have venomous fangs for killing prey. Other snakes squeeze their prey until they suffocate it.
Snakes swallow their prey whole.

37. Kinds of Reptiles, continued
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Kinds of Reptiles, continued
Most lizards eat small insect and worms, but some lizards eat plants.
Many lizards can break their tails off to escape predators and then regrow new tails.

38. Kinds of Reptiles, continued
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Kinds of Reptiles, continued
Tuataras Tuataras live on only a few islands off the coast of New Zealand.
Although they look similar to lizards, the two reptiles have some obvious differences. Tuataras do not have visible ear openings.
Unlike other reptiles, tuataras are most active when the temperature is low.