FUN FACTS ABOUT SHARKS • A group of sharks is called a shiver. • You’re more likely to die from a lightning strike or a bee, wasp, or hornet sting than from a shark attack. • Sharks are relatives of manta rays. • Sharks have been on Earth longer than trees.

Sharks do not have bones. Sharks use their gills to filter oxygen from the water. They are a special type of fish known as "elasmobranchs", which translates into fish made of cartilaginous tissues— the clear gristly stuff that your ears and nose tip are made of. This category also includes rays, sawfish, and skates.

The first sharks lived more than 400 million years ago—200 million years before the first dinosaurs. They have changed very little over the eons. Shark don't have vocal cords. They communicate through body language, such as head butts, shaking their heads, or even hunching their backs.

Sharks live in every ocean on the planet. Sharks have eight orders of classification depending on their physical characteristics. Sharks are cartilaginous. What makes sharks different from fish is that their skeletons are made of cartilage instead of bone. Sharks are also different from bony fish because they have eyelids.

Some sharks have belly buttons. Many sharks are viviparous, meaning they give birth to live young. Like all sharks, species such as blue, bull, and hammerhead sharks rely at first on a yolk sac for nutrition. But they also develop a placental connection similar to a mammal’s umbilical cord.