As MNN reports, "The hammerhead's increased ampullae sensitivity helps it track down its favorite meal, stingrays, which are usually hidden under the sand. They can be as terrifying as the great white shark or as docile and harmless as the basking shark. The largest embryo in a shark litter is known to eat its fellow embryos, in an act known as intrauterine cannibalism. They can grow as long as the semis you see on the interstate, in the case of the whale shark, or they can be only as long as your mobile device, in the case of the dwarf lantern shark. For example, when attacking an elephant seal, a great white will immobilize it by taking a bite out of its hindquarters and retreating, returning once it's died and won't struggle. Great whites' famously powerful sense of smell comes from its giant olfactory bulb, an organ that connects to its nostrils and allows it to detect prey with impressive sensitivity. Here are 10 fun facts about sharks that will give you a new appreciation for this ancient beast that has swam the world’s oceans for 420 million years and miraculously survived all five of the earth’s major mass extinctions. "The eyes of hammerhead sharks are tilted slightly forward," as BBC Earth put it, "allowing the field of vision of each to significantly overlap.". In another case, a hammerhead shark gave birth in a Nebraska aquarium without mating at all. Login or Register above to download the content. While many people think of sharks as ferocious predators that might attack at any time, divers have a different point of view. Since both humans and sharks are jawed vertebrates, we share a common ancestor, believed, according to Nature, to be the Acanthodes bronni. Shark teeth from millions of years ago have been preserved at the bottom of the ocean. But, there are only a few such animals that are as much threatening as the sharks to the human beings. Defenders of the Wild. Your email address will not be published. Sandy sediment that covered the shark teeth protected them from oxygen and bacteria, allowing them to fossilize over the course of 10,000 years. Here are ten exciting facts you may not know about these majestic marine creatures. You thought nine months seemed like a while, but the spiny dogfish species of shark can take two years to gestate before delivery—making it the longest gestation period of any vertebrate. Out of over the 350 different species of sharks that we have, only about 30 of these species have … And even more horrifying is that the study suggested that 100 million is a low estimate, and the real number may be as high as 273 million, or 519 sharks every minute. It may be reaching these depths in order to search for food, especially when crossing the ocean water, food is little on the surface. As the largest fish in the sea, whose lengths are 40 feet or more, whale sharks have a huge menu that you can choose from; fortunately we humans are not on this list. The animals go back to the late Silurian period when coral reefs were first beginning to form. Whale sharks have been known to give a ride to hitchhiking swimmers, and cruise through the water atop them. There is some evidence to suggest that not all babies are born all at once, but over a long period. A shark may grow (and lose) over 30,000 teeth in its lifetime. Trivia sure to send you scrambling for shore. But since this doesn't work as well on sharks, according to Smithsonian, "Recently, scientists have been using a new method of determining shark age: by using a radiocarbon timestamp found in the vertebrae of sharks left over from nuclear bomb testing in the 1950s and 1960s.". That strategy allows sand tiger sharks to have much larger babies at birth than other shark species, making the little ones relatively safe from other predators." 6. There are some estimates that for every person killed by a shark, 25 million sharks are killed by people on an annual basis. By Justin Kovach. They also have, on average, as many as seven replacement rows of teeth behind the front row, ready to move into place if a tooth is damaged or falls out. July 10, 2018. The pores connect to long, jelly-filled bulbs that connect to nerves below their skill. Great whites do specialize in sneak attacks. The United States averages about 19 shark attacks a year, with one fatality every two years. For instance, whale sharks (which generally range from 18 to 32 feet/5.5 to 10 meters in length) can live up to 100 years, while the smooth dogfish (with an average length between 2 and 4 feet/0.6 and 1.2 meters) might only live for 16 years. It’s interesting that the largest fish in the sea eats the smallest creatures in the sea. Discuss their benefits or other measures that may be necessary to ensure their survival. As the whale shark swims through water with its mouth open, a built-in filter, commonly known as a “gill raker,” traps teeny tiny and microscopic plankton, which is their main form of nourishment. Required fields are marked *. If you’re snorkeling or diving, it’s good to be aware of the body language sharks use to communicate that they’re uneasy. That full formation extends to the teeth of baby sharks, with shark pups entering the world with a full set of teeth intact and ready to fight off threats—including their littermates and own mother. Teeth of the sharks do not have any root. Most of the time is spent in the crustal or surface layer of the ocean that reaches a depth of 200 meters. We have more in common with them than you'd think. As huge as some sharks may be, their ancestors are even more impressive. It's hard to think of creature more awesome, in a literal sense, than the shark. Sharks are so tough, their embryos are known to attack one another. Those razor-sharp chompers hide a treasure trove of secrets and surprises—and yes, we went hunting for said treasure. Viviparous sharks include blue and hammerhead sharks, which grow live sharks in their bellies, which are nourished with a type of placenta, and give birth to fully developed shark pups. Meet the bikes that cost more than a car. Shark Guardian Shark and Marine Conservation Projects Worldwide. Those not killed directly by the hands of humans end up trapped in fishing nets or on longlines. And for more secrets from the seven seas, see the 30 Facts About the World's Oceans That Will Blow Your Mind. Sharks have been around for a long, long time—about 450 million years, according to scientific estimates.