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LEVELED READER • Q
Written by Kira Freed • Illustrations by Cende Hill
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Sharks
A Reading A–Z Level Q Leveled Reader • Word Count: 1,376
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Photo Credits:
Front cover, back cover, title page, pages 4, 5, 6, 10, 11, 12,
15, 17, 22, 23: © Digital Stock; page 16: Dr. Mathew Gilligan,
National Oceanic and Atmospheric Administration/Department
of Commerce; page 21: William B. Folsom, National Oceanic
and Atmospheric Administration/Department of Commerce
Sharks
Level Q Leveled Reader
© 2002 Learning Page, Inc.
Written by Kira Freed
Illustrations by Cende Hill
ReadingA–ZTM
© Learning Page, Inc.
All rights reserved.
Learning Page
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Correlation
LEVEL Q
Fountas & Pinnell
Reading Recovery
DRA
N
21
30
www.readinga-z.com
Written by Kira Freed
Illustrations by Cende Hill
Table of Contents
Introduction .........................................................................................4
Physical Description .............................................................................7
Eating .................................................................................................10
Reproduction ......................................................................................14
Shark Attacks......................................................................................15
Strange Sharks....................................................................................17
Shark Survival.....................................................................................21
Glossary .............................................................................................24
3
4
Blue shark
Sharks have lived in the
world’s oceans for more
than 350 million years.
They even lived before
dinosaurs walked on Earth.
There are more than 350
kinds of sharks. They can
be found from the equator
to the poles, and from
shallow seashores to the
deepest waters. Sharks are
possibly the world’s most
successful hunters.
Introduction
Sharks are the great hunters of the world’s oceans. They have an
excellent sense of smell and are able to see well in poor lighting. Sharks can
sense the slightest movement of other animals. They are especially sensitive
to the sounds and movements of injured animals. Sharks can even sense
tiny bits of electricity, which are produced by all living things. Sharks can
sense fish buried under the sand on the ocean bottom. People have even
found shark tooth marks in electrical cables that run along the ocean floor.
Mako shark
6
5
Sharks are fish, but they are different from most other fish. Sharks have
no bones. Instead, their skeletons are made of cartilage, which is the same
material that forms our outer ears. This makes sharks very flexible and light.
They also do not have scales on their skin, as most fish do. Instead, they
have rough skin. The closest relatives of sharks are skates and rays, which
are flat, diamond-shaped fish. They also have skeletons made of cartilage.
Southern stingray
Illustration of a swell shark. The dotted
line indicates the shape of the shark’s
belly when it is puffed up.
Most large sharks are so fierce that they have few natural enemies.
Smaller sharks are often protected by camouflage patterns that help
them blend with their surroundings. Even large sharks use camouflage.
They are dark on the top and pale on the bottom. This helps disguise
a shark’s outline so it is harder to see. Some sharks, called swell sharks,
protect themselves from attack by puffing up their bodies with air or
water. This makes them appear larger and helps to keep predators away.
8
7
Sharks come in many sizes. Some dogfish sharks are only a few inches
long. The whale shark is the largest fish in the world. It can grow as long
as two buses and can weigh as much as three elephants. Most sharks have
powerful, streamlined bodies to help them swim quickly and catch their
prey. They have pointed noses and long, slender bodies that look like
torpedoes or airplanes.
Physical Description
Size variation
in sharks and
comparison
with human
spined pygmy shark
great white shark
whale shark
Eating
Most sharks’ mouths are located
on the underside of their heads. The
shape of a shark’s teeth depends on
the kind of food it eats. Most sharks
have many rows of teeth in their
mouths. When one tooth breaks off,
the one in the row behind it moves
up to take its place. Sharks’ teeth
break off easily. Many sharks have
jaws that fit loosely in their heads.
Their jaws can swing forward to bite
prey, and then pull the food back in
toward the shark’s stomach.
10
Do You Know?
A shark may wear out and regrow
a thousand teeth during its lifetime.
Great white shark
9
Sharks swim by swinging their tails from side to side. They have fins
on the top, sides, and underside of their bodies. Fins help sharks steer,
turn, and keep their balance. The dorsal fin, which sharks use to keep
upright, sometimes sticks out above the water. This can let humans
know a shark is present.
caudal fin
anal fin
pelvic fin
pectoral fin
second dorsal fin
dorsal fin
Other sharks, such as cat
sharks, eat clams, crabs, and
lobsters. These sharks have flat
teeth for crushing and grinding
shells. The huge whale shark
has no teeth at all. It eats tiny
ocean plants and animals, called
plankton, that float and drift on
or near the ocean’s surface. It
swims with its enormous mouth
open, swallowing water as it
moves along. Special filters in
its gills catch the plankton and
let the water flow through.
12
Do You Know?
The word “plankton” comes from the
Greek word for “drifting.” Plant plankton
are called phytoplankton. Animal plankton
are called zooplankton.
Whale shark mouth
11
Most sharks are fish eaters. Many of the largest sharks eat sea lions,
dolphins, and other sharks. These large sharks have triangular teeth with
edges as sharp as knives. The teeth point backward to help the shark catch
and hold onto its prey. They also help the shark tear its prey into chunks
that it can swallow.
Great white shark
A great white shark
can swallow a whole
seal in one gulp.
Do You
Know?
Do You Know?
Unlike humans, baby sharks are
not helpless when they are
born. They are able to hunt for
food right away.
A dogfish egg case
Reproduction
Baby sharks are called pups. Most kinds of sharks bear live young.
A few kinds of sharks, including the dogfish, lay eggs that hatch a few
months later. Each egg is protected by a leathery egg case while the
shark is developing. The cases are rectangular, and many have stringshaped ends that attach to seaweed. Some people call shark egg cases
“mermaids’ purses.” Most sharks have fewer young at a time than
other fish do. Sharks usually have only one or two pups at a time.
14
13
Many sharks are accompanied by pilot fish. These small fish swim close
to sharks, waiting for scraps of food to float by when the shark feeds. Other
small fish, called cling fish, cling to the shark’s body and keep the shark’s
skin free of parasites. Cling fish also feed on leftovers from shark meals.
These fish are safe around sharks because few of their predators dare to
come near a shark.
Cling fish
attach themselves
to a shark’s body.
Do You Know?
Of the millions of people who
swim in oceans every year,
only about a hundred are bitten
by sharks.
Nurse shark
Other kinds of sharks also have attacked humans. Even small sharks
may bite if disturbed or surprised. Shark attacks are usually the result
of people swimming in shark territory. People who swim too close to a
shark or who startle it are in danger of being attacked. Many scientists
think that sharks confuse swimming humans with their normal prey.
Many shark attacks involve the shark taking one “test” bite and then
swimming away when it realizes that the human is not its normal prey.
16
Great white shark
15
Sharks have a reputation
for being terrifying, but most
sharks do not attack humans.
In fact, bees kill more humans
each year than sharks do.
Only a few kinds of sharks
are known to attack humans
regularly. One of these is the
great white shark, which can
even attack small boats. Great
white sharks usually eat large
animals, such as sea lions and
other sharks.
Shark Attacks
Cookie-cutter shark
Close-up of mouth of
a cookie-cutter shark
The cookie-cutter shark is a very small shark that has a rounded
mouth and extremely sharp teeth. It takes circular bites out of seals,
whales, and dolphins. The bites do not kill the victims, but they leave
round scars in the shape of cookies. The cookie-cutter shark also has
skin that glows dimly in the darkness of the ocean.
18
17
One of the strangest looking sharks is the hammerhead shark. It has a
flat head with large lobes on each side. The eyes and nostrils are positioned
on the ends of these lobes. Its strange head shape helps the hammerhead
see around and behind it. There are nine kinds of hammerhead sharks.
Strange Sharks
Hammerhead shark
Wobbegong shark
The wobbegong shark is a master of camouflage. It is covered with
colorful splotches and spots that help it blend in with seaweed, sand, and
pebbles on the sea floor. The wobbegong also camouflages its body shape.
It has fringes of skin around its head and mouth that resemble the shape
and movement of seaweed and coral. A curious crab, lobster, or fish may
think these flaps of skin are plants—that is, until it becomes a tasty meal.
19
20
The thresher has a whiplike lobe at the top of its tail. When a
thresher finds a group of fish, it swims in the middle of them and
moves its tail around violently. Many fish are either killed or stunned,
which makes them easier to capture and eat. The thresher’s tail makes
it a very strong swimmer. It can leap completely out of the water.
Thresher
Shark fishing boats
Shark Survival
Sharks are hunted for many reasons. Sharkskin is used to make shoes,
belts, and wallets. Shark oil is used in many cosmetics. Shark teeth are used
for jewelry. Shark meat is eaten by many people. Shark fins are used in a
popular soup, and the shark usually dies when its fin is removed.
21
22
Many kinds of sharks are now in danger of extinction (being
completely wiped out). People often do not protest when sharks
are killed because sharks are thought to be mean and dangerous.
However, most sharks are dangerous only when they are trapped
and fighting for their lives.
Great white shark
Glossary
tiny plants and animals that live on or near
the ocean’s surface (p. 12)
plankton
the process by which an entire group of animals
or plants dies out (p. 22)
extinction
the fin on the top of a shark’s body (p. 9)
dorsal fin
an elastic tissue that makes up the skeletons
of sharks, rays, and skates (p. 5)
cartilage
an adaptation whereby many sharks and other
animals blend in with their surroundings in order
to be less visible to predators (p. 8)
camouflage
24
23
Sharks do not reproduce nearly as quickly as other fish. When they are
killed, it takes much longer for their numbers to increase again. Sharks are
a top predator, meaning that they are at the top of their food chain. They are
an important part of the balance of life in the world’s oceans. They have as
much right to exist as any other animal.
Gray reef shark