WRITE ON! Sandra Markle: Dive Into SHARKS: BIGGEST! LITTLEST!

These fun activities will let you dive into my book SHARKS: BIGGEST! LITTLEST! to investigate some of the world's most fascinating sharks. You'll discover that big or little or having special big or little features is how sharks are just naturally adapted to being a success in their part of the ocean.

Size Matters!

Rearrange the list of sharks in order from the biggest to the very smallest.

Adult Whale Sharks, like this one, can be 45 feet (about 14 meters) long.

Start by looking at the photos and reading the text. For even more clues, check out the map on page 30.
Swell Shark
Cookie-Cutter Shark
Whale Shark
Basking Shark
Port Jackson Horned Shark
Thresher Shark
Ornate Wobbegong Shark
Longnose Sawshark
Spined Pygmy Shark
Great White Shark

Would You Believe?

Can shark skin be used as sandpaper?

Like your teeth and a shark's teeth, denticles have a soft center pulp and a hard enamel coat.

Read pages 12 and 13 to discover a shark's body is covered with little parts called denticles. Search on Google to find out if anyone ever used shark skin for sandpaper in the past.

Check out this Myth Busters episode to see a test to find out if shark skin will work as sandpaper.

Thanks to all its denticles, this Swell Shark looks like a rough character. You might be surprised to learn the denticles do more than act like a suit of armor. The shape helps a shark slip move more easily through the water. Sharks also regularly shed and replace denticles just the way they do the teeth in their jaws. As they grow bigger, some kinds of sharks add more little denticles to cover their body. Others replace smaller denticles with larger ones.

A Shark Gave Me The Idea

There are lots of special things about sharks. Check out the follow list. Then think of something you might invent for people to use based on something special about sharks.

See the nictitating membrane partly covering this blue shark's eye.

Some sharks have a special eye membrane, called a nictitating membrane. When the shark gets close to something, such as its prey, this moves over the eye to shield it. Great Whites have a set of muscles that roll the entire eye into its socket to protect it.

A shark's nostrils are on the outside of its body and lead into nasal sacs. These aren't for breathing--only smelling. The sacs are made up of lots of folds of tissues, all packed with scent sensors. No wonder a shark can detect as little as five drops of blood mixed into the amount of water it takes to fill an average swimming pool.

These spiracles are on a zebra shark.

What look like freckles on some sharks are the openings of special electricity sensors. These let the shark detect tiny charges produced by a prey's heartbeats or muscle movements. This lets the shark be particularly sensitive to wounded animals, the easiest prey to catch.

A shark can move its upper jaw forward and out to bite. You can only move your lower jaw.

A shark's skeleton is entirely cartilage, the rubbery kind of supporting structure you have in your external ear. That helps sharks in a number of ways. Cartilage is lighter than bone, which helps sharks stay afloat. It's also more flexible than bone, letting sharks make really tight turns.

Shark Tale

Pick one of the sharks you read about in SHARKS: BIGGEST! LITTLEST!.

This Ornate Wobegong Shark ambushes its prey using fanglike teeth to snag its prey.

Read the section about that shark again. Next, go on-line to learn more about the life history of the shark you picked. Then write a short story about a day in the life of that shark. This will be a factional story, a made-up story packed full of real facts.

Look Again!

The pictures in SHARKS: BIGGEST! LITTLEST! have their own stories to tell. Take another look at the pictures in the book to answer these questions.

Cookie Cutter Shark takes a bite on pages 10 and 11.

A Great White Shark's mouth has five or more rows of teeth. Do all the rows stand up straight or do some of the teeth lie flat?

Do Cooke-Cutter Sharks have lower teeth that are different sizes and shapes or are they all the same size?

Are sharks as big today as during prehistoric times? How do you know?

Which sharks that appear in the book have their mouths at the front end of their head? Which have their mouths under a nose?

Sharks For Good Measure

An adult Great White Shark never stops growing. So it gets a little longer every year of its life. They're born alive and about four feet (1.2 meters) long at birth. One of the biggest kinds of sharks, adults often grow to be 20 feet (6 meters) long. Measure off a piece of string that length. Stretch it out on the floor and lie down next to it with your feet at one end of the string. Set something, like a pencil, across the string next to your head. Now, use a measuring tape to find out how many feet/meters shorter you are than a Great White Shark.

Now, find at least 3 things about the same length as a Great White Shark. What are they? Now find out how much longer or shorter each of the following things is compared to a Great White Shark.

The class's two tallest students lying head to feet on the floor
Your school's librarian
The length of the school principal's car.

While you're measuring, here's some cool facts you'll enjoy learning about Great White Sharks:

Mother sharks give birth to as many as 60 babies at one time. The babies are on their own immediately after they're born.

Great White Sharks swim very fast compared to other sharks. They've been clocked swimming as fast as 40 miles per hour. But they can never stop swimming. They sink if they stop moving. Their bodies also aren't designed to let them swim backwards. So they can't backed up.

More Action