March 13, 2011
Noah from Hamilton, Ohio, wrote recently with a good question. He asked: "What is the biggest shark?"
I told Noah that the Whale Shark (Rhincodon typus) is the largest shark in the world. In fact, it is the largest living fish species.
Then, I suggested to Noah that he do some research and come up with some more interesting information about the whale shark. Here is part of what he wrote:
"I found a lot of good facts about Whale Sharks. One is they have no known predators. Another fact is they use their stripes and dots as camouflage through disruptive coloration."
Noah is correct. "Disruptive coloration" is a common type of camouflage that we see in nature. The mix of different patterns (in the case of the whale shark, both stripes and dots) is thought to hide the overall shape of the animal’s body, making it more difficult to spot in the water.
When I say that a whale shark is big, I mean really BIG! The whale shark can grow as long as 41 feet and weigh as much as 15 tons.
To understand just how large that is, look at this drawing from Wikipedia, which shows the size of a Whale Shark compared to the size of an adult human. These huge fish are found in tropical and warm water oceans, and have been known to live as long as 70 years.
There is no reason to be afraid of whale sharks. They are not predators; rather, they are slow-moving filter feeders. Animals who are filter feeders simply open up their mouths and take in whatever food happens to be in the water, while filtering out the undesirable debris. Whale sharks feed mainly on tiny bits of food like plankton, as well as microscopic plants and animals.
If you want to read more about sharks, you can probably find one or more of my books in your school library. There is a Smithsonian book called SHARKS and a SeeMore Reader called INCREDIBLE SHARKS, which is also available en Español: TIBURONES FABULOSOS. Some of you may have ordered my book SHARKS: 3D from the Scholastic Book Club.
If you are wondering why I have written so many books about sharks, it’s because they are fascinating to me, just as they are to you!
Note to Parents, Teachers and Librarians: There is a free, downloadable Sharks Teacher Guide on my website, which I invite you to use to enhance the reading experience of students who are reading these books.
Whale Shark Photo: Zac Wolf
Posted by: Seymour Simon
