Baby sharks are called pups, male sharks are called bulls and female sharks are just called females.
Shark pups are born or hatch fully nourished. While they can swim right away, they don't need to hunt for food for the first few weeks of their lives.
What happens to sharks when they get old? If they evade other predators, they die from heart or liver problems, kidney failure, or other diseases – just like us.
Shark life expectancy varies dramatically. Blue sharks only live for about 16 years, while Greenland sharks can live up to 200 years ago. That means there could be sharks alive now that were born when James Madison was in the White House.
People think of tropical waters when they think of sharks, but some sharks can survive in freezing waters, like Greenland sharks, slow-moving sea sharks that typically swim about a mile below the ocean's surface. They are the northernmost of all sharks.
Talk about your social network! While some sharks are loners, Hammerheads gather in schools. No one is sure why, but it may be to help protect themselves from larger predators, or to help males find mates.
Hammerhead sharks have been around for millions of years – long enough for different species to develop different-shaped heads.
Do sharks ever sleep? Many species need to keep moving to keep water moving over their gills, but some sharks can find places where the ocean currents are strong enough to keep water flushing over their gills, allowing for short naps.
Many male sharks let females know they are interested in mating by biting them. That's why female sharks develop tough skin – sometimes three times as thick as the males in their species.
Blue sharks are notorious for over-eating, but that doesn't mean they are fatties. Some food may remain in their bodies undigested for days or even weeks until it's needed for energy. That allows them to keep swimming even during periods when food isn't readily available.
Bull sharks are one of the few varieties that can live in either salt or fresh water. That's why they've been spotted in the Mississippi River as far north as Illinois, and why they were found in Lake Pontchartrain in the aftermath of Hurricane Katrina. Bull sharks are anything but docile. They're territorial and will attack when threatened – even animals that are larger than them.
Thresher sharks have the longest tails, which can grow to half their body length and can be used as weapons. But those tails pose a liability, too, since they can get caught in nets and fishing lines.
That should give you a few fun facts to share in the break room as you eat your tuna fish sandwich.
con't from pg. 53
Shark Week - Final