Facts About Sharks

chapter 6

Shark Facts #49. Between 30% and 80% of a shark's flesh is made of water. A protein network gives the flesh its structure.
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Shark Facts #48. It takes a lot of work to maintain a gene pool: Some female sharks use sperm from multiple males to father a single litter. That makes her pups half-siblings, even though they're born at the same time.
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Shark Facts #47. Angel sharks, also known as sand devils, will dig themselves into piles of sand. They lie in wait, waiting for unsuspecting fish to pass by before rising up and attacking.
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Shark Facts #46. Jaws is considered to be the godfather of all shark movies, but six years before the Steven Spielberg blockbuster, Burt Reynolds got into a wet suit to star in Shark.
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Shark Facts #45. Whale sharks are three times larger than the average shark, but don't be afraid of these docile creatures. They are filter feeders that use their many rows of teeth to gather plankton, making them great diving companions for eco-tourists.

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Shark Facts #44. The size of a shark species relates to where they hunt: Smaller sharks tend to feed near the ocean floor, and larger sharks hunt in the middle depths and near the surface, where they can more easily snatch larger prey such as seals.
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Shark Facts #43. Some sharks start working before they're even born, chewing their way out of their egg to enter the open ocean.
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Shark Facts #42. The Aztecs attached strings of chili peppers to their canoes to keep sharks away, a practice that modern day scientists doubt was actually effective.
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Shark Facts #41. Reef sharks number among the shark species that have to keep moving so they can breathe. But in the 1970s, scientists discovered a place called the Cave of Sleeping Sharks near Mexico, where reef sharks could lie motionless. High levels of oxygen and low levels of salt in the water keep the sharks alive.
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Shark Facts #40. The Aztecs had a mysterious mastery over sharks. In 1978, archaeologists uncovered remnants of shark bodies under the ruins of the Aztec Great Temple. The sharks were likely used as a sacrifice to the gods.
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Shark Facts #39. Recreational shark fishing, which has become a large threat to the shark population, wasn't popular until 1975. After the premiere of Jaws, people wanted to snag a "man-eating" great white.
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Shark Facts #38. Blue sharks are piggy eaters. They'll keep eating until they regurgitate, after which they go back to eating!
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Shark Facts #37. Like lions on land, sharks are at the top of the food chain in the underwater jungle, and their eating habits affect the populations of all sea life below them. Without large sharks, octopus populations would jump, which would then decrease the number of lobsters, since they are one of the octopus' favorite snacks.
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Shark Facts #36. When on the hunt, sharks stalk their victims, staying far enough away to be hidden, but close enough to strike when the opportunity arises.
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Shark Facts #35. Electroreception allows sharks to notice the smallest changes in the electricity conducted through saltwater. Blood in the water changes its conductivity. So, sharks don't see blood and attack: They sense and smell it. See video at shark fact #30
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Shark Facts #34. Instead of closing its eyelids, a great white shark rolls its eyes into the back of its head when it attacks. This behavior helps the shark protect its eyes from debris and the thrashing of its prey.
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Shark Facts #33. It's possible that shark repellants could come from an unlikely source: magnets. Magnets in the water can interfere with a shark's electroreception. Don't just strap on some magnets and head to the beach, though. With current technology, sharks have to get very close to the magnets before they're affected.
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Shark Facts #32. You are more likely to be killed by a falling coconut than being killed by a shark. Roughly 150 people are killed each year by coconuts compared to sharks killing only 4-12 people a year. Coconuts are more dangerous than sharks!
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Shark Facts #31. Turkish car designer Kazim Doku designed a concept car modeled after the body of a shark. It's a hovercraft - after all, sharks glide through the water and don't clunk around on land - that won Audi and Milan's Domus Academy's 2008 Desire Design Competition.
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Shark Facts #30. Sharks can use heartbeats to track their prey. Sharks have nodules on their noses about the size of a pimple, called ampullae of Lorenzini. These nodules sense electricity, so the electrical pulses that come from a beating heart can act like a beacon for nearby sharks.