Port Jackson sharks lay eggs that have a corkscrew shape.
Basking sharks suck in more than 10,000 quarts of plankton-filled water in one hour.
Sharks have 5 to 7 pairs of gills on the sides of their heads, which they use to extract oxygen from water.
Great white, mako and salmon sharks will drown if they stop moving because water won't pass over their gills.
Some sharks have strong cheek muscles and can store water in their mouths to force over their gills.
Great white sharks like to roam, and may travel thousands of miles between favorite feeding grounds. Other sharks are relative homebodies, like the angel shark, which lives in a relatively small area.
Shipwrecks are like a playground for sharks. Hulls sink to the ocean floor, where they eventually develop their own ecosystems, attracting all manner of marine life, including sharks.
Very few of the more than 350 species of shark – a small minority – are known to attack humans. Great Whites, Tiger & Bull sharks are responsible for the majority of shark attacks on humans. Shark attacks on humans run about 50 times a year. And of those attacks less than 10% are fatal.
Sharks don't actually chew their prey, but tear it up into chunks and swallow.
Sharks' eyes are on the sides of their heads, so they have an amazingly wide sightline spanning nearly 360 degrees.
Sharks have highly tuned inner ears that help them hear their prey from a distance of up to two city blocks away.
The Cookie Cutter shark is a master of camouflage. This shark's underside glows, with the exception of a small strip on its neck that looks like a much smaller fish.
Predators mistake this strip for a snack, and the Cookie Cutter takes a bite of their flesh before swimming away.
A shark's tooth-shaped scales are designed for dynamic movement but have also been mimicked in biotechnological research for their ability to repel barnacles and algal growth.
Sharks can sense injured fish that make infrasonic sound vibrations in the water and quickly become an easy dinner.
Some shark species moms can be pregnant for up to two years.
Some sharks can glow in the dark using light-emitting organs called photospheres. That allows them to live in deep, dark waters but still have the ability to see prey or be visible for mating.
Sharks living in frigid waters can heat their eyes using a special organ next to a muscle in their eye socket to keep hunting their prey in extreme temperatures.
Sharks never run out of teeth. They have new ones on a "conveyor belt" at the ready to move up and replace any that become lost during feeding. Some sharks can produce over 30,000 teeth in their lifetime.
Sharks have existed almost unchanged for 400 million years – long before the dinosaurs – and yet are at risk from human activities such as fishing.
50-foot Megalodon sharks swam the oceans for more than 50 million years, but became extinct about 35 million years ago. These sharks inspired "Megalodon: The Monster Shark Lives” a fake two-hour documentary that enraged Shark Week fans in 2013.
Salmon sharks are the world's fastest sharks and can swim up to 55 miles per hour.
Great white sharks eat more than 20 times what a human eats in a year.
The Bluntnose Sixgill shark can dive as deep as 7,550 feet, or the length of more than five Empire State Buildings.
The largest shark family, scyliorhinidae, is comprised of about 90 catsharks, many of which are commonly called dogfish.
con't from pg. 7