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Karsten Hartel / Wikimedia Commons

14 Facts About the Cookiecutter Shark

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Karsten Hartel / Wikimedia Commons

The cookiecutter is a cinematic star thanks to a supporting role in the 2011 horror film Shark Night 3D, but there’s a lot about this rarely-seen shark that’s still a mystery. Here are a few things we do know.

1. It’s had three scientific names: When the shark was discovered in 1824, it was named Tristius brasiliensis, followed by Scymnus brasiliensis, and, finally, its current name, Isistius brasiliensis. The genus name refers to Isis, the Egyptian god of light; the species name refers to one place it's found, off the coast of Brazil. 

2. Its common name comes from the cookie cutter-like wounds it leaves in its prey. Its shape has also led some to call it the cigar shark. If you prefer to refer to it in another language, though, the Florida Museum of Natural History has you covered: almindelig cookiecutterhaj (Danish), cação luminoso (Portuguese), kleiner leuchthai (German), koekjessnijder (Dutch), squalelet féroce (French), and tiburón cigarro (Spanish) are just a few you could use.

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3. The name cookiecutter is somewhat misleading—the shark’s bites are actually conical. (Ed Yong at National Geographic suggests that “ice cream scoop shark” might be more accurate.) 

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4. The entire underside of the cookiecutter glows thanks to light-emitting organs in its skin called photophores. Some scientists think the sharks use this bioluminescence to blend in with the moonlight, while a dark, unlit collar around its throat, which resembles a fish, draws its prey up from the bottom. (The sharks are also capable of using the organs to flash like a strobe light.) However, George Burgess, a shark expert at the Florida Museum of Natural History, told Wired that the collar does, in fact, glow, and “suggests that by flashing, the band may help draw would-be predators to the 'business end' of the shark.” Regardless of what’s luring the prey, once it’s close enough, the cookiecutter does a bait and switch and has a meal itself.

5. The fish lives at depths of 3200 feet during the day, but migrates vertically at night to feed.

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6. Speaking of eating: To feed, the shark uses its suctorial lips to suction itself onto its prey. Once it’s attached, the cookiecutter spins its body, using the row of serrated teeth on its lower jaw to remove a plug of flesh—leaving behind a crater-like wound that is 2 inches across and 2.5 inches deep—and dinner is served.


7. The sharks typically feed on animals much larger than them, including tuna, stingrays, other sharks (even great whites!), seals, whales, dolphins, and more.

8. They’ve even bitten humans. There have been a couple of cases where the sharks have fed on bodies in the water, and one long distance swimmer, Mike Spaulding, was bitten by a cookiecutter while doing a night swim off the coast of Hawaii. Spaulding later described the circumstances behind the incident to Deep Sea News:

I was swimming along in perfect conditions. The wind kicked up a little and I was hoping that it was a local condition that would disappear. We were on 30 min[ute] feeding schedule. At 8:15 I was trailing the boat by about 80 to 100 yards. The boat captain liked to run ahead and then go out of gear and wait for me to catch up. On the previous feeding stop he complained about not being able to see the Kayak and requested we turn on our emergency light so he could see us better. He also turned on his cabin lights at the same time. Fifteen minutes after we turned on the lights and I had my feeding I started to feel squid bumping into me. I assumed they were squid as they felt soft. I did not like this at all ... After the 4th bump I felt a sharp prick just to the left of my sternum. It was excruciating and I gave a yelp. As soon as that happened I knew I had to get out of the water and the swim was over. I reached the front of the kayak and turned off the light and started climbing into a one person kayak. As I was about to push onto the kayak I felt a hit on my left calf. I ran my finger down my leg and felt a 2.5” by ¾ inch hole where I had been hit. … The lights attracted squid with in turn created a food chain which the cookie cutter shark was a part of.

Still, despite what Shark Night 3D would have had you believe, they’re not a danger to us.

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9. The shark loses its bottom row of triangular teeth—25 to 31 of them—as a unit, then ingests them, probably for calcium. Cookiecutters also have 30 to 37 tiny teeth on the top jaw.


10. The shark was discovered in the 1800s, but no one knew it was responsible for the marks on other sharks until the 1970s. According to Yong, “The first breakthrough came in 1963, when a man called Donald Strasburg noticed that the cookie-cutter shark would shed its saw-like lower teeth as a single unit. … In 1971, Everet Jones discovered small conical plugs of flesh in the stomachs of these sharks. He also noticed that their mobile tongues and large lips allow them to form a vacuum on a smooth surface. It became clear that this tiny animal was wounding some of the ocean’s mightiest residents.”

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11. Some inanimate objects also have something to fear from cookiecutter attacks: The shark posed a threat to nuclear submarines in the 1970s. Cookiecutters took chunks out of the neoprene-covered sonar domes of several American subs, which caused the sound-transmitting oil to leak and blinded the vehicles. To solve the problem, the domes were covered with fiberglass. Telecommunications and oceanographic research equipment have also been damaged by cookiecutters.

12. The shark is small: Males grow to a maximum of 16.5 inches, while females grow to 22 inches.

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13. Cookiecutters give birth to live young that develop inside egg sacs in the shark’s uterus; the mother gives birth shortly after the baby cookiecutters hatch out of the egg cases.

14. Reportedly, a shark's photophores can emit a glow up to three hours after it dies. Creepy!

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Watch as Hummingbirds Fly, Drink, and Flap Their Tiny Wings in Slow Motion
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Hummingbirds have more feathers per inch than nearly any other bird, but it’s hard to fully appreciate their luminescent colors when they beat their wings between 70 to 200 times per second.

For the enjoyment of birders everywhere, National Geographic photographer Anand Varma teamed up with bird biologists and used a high-speed, high-resolution camera to capture the tiny creatures in slow motion as they flew through wind tunnels, drank artificial nectar from a glass vessel, and shook water from their magnificent plumage.

[h/t The Kid Should See This]

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9 Wild Facts About the Bronx Zoo
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Even if you’ve never set foot in New York, you almost certainly know of the Bronx Zoo. Opening its doors for the first time in 1899, this sprawling 250-acre wildlife reservation has over 4000 different animals and 650 species. Take a look at a few things you might not have known about one of the world’s most famous zoological retreats.


William Temple Hornaday was working as a taxidermist for the Smithsonian Institution when he noticed that the nation’s population of bison was shrinking. Eager to promote conservation efforts, Hornaday used his voice with the Smithsonian to spread the word about the threatened species. After a spat with the Institution, he was approached by the New York Zoological Society in 1896 to serve as director of the Bronx Zoo. In doing so, Hornaday helped bring the bison back from the brink of extinction by sending several of the Zoo's bison back out west in 1906. He remained with the zoo for 30 years.


Thylacines, or Tasmanian tigers, were nearing extinction in the early 1900s, but the Bronx Zoo was able to acquire several for exhibition beginning in 1902. The first lived for six years; the next two, arriving in 1912 and 1916, lived only a short time in captivity before perishing. The zoo's last thylacine was secured in 1917. The species was thought to have died out in 1936, but in early 2017, several eyewitness accounts of the distinctive animals were reported in Australia. Zoologists are working to determine if the thylacine might still be alive.


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In the most ignoble chapter in the zoo’s history, organizers opened an attraction in 1906 that featured a "Mbuti pygmy” or “bushman”—an African man named Ota Benga. Benga and other tribesmen had been brought to America by anthropologist Samuel Verner at the behest of organizers of the 1904 St. Louis World's Fair so visitors could gawk at them in mock-up villages. When the fair was over, Verner brought Benga and others back to Africa: the two struck up a friendship, and Benga reportedly asked to come back to the States. Verner approached the Bronx Zoo with the prospect of Benga becoming a fixture: Hornaday agreed to let him live on and roam the grounds. Public outrage followed, and Benga was released after just two weeks to the care of an orphanage. He committed suicide in 1916.


Too much children’s literature about cuddly bears may have proven disastrous for early zookeepers at the park. In 1919, Hornaday told the New York Tribune that he had to constantly warn his employees not to try and befriend the mammoth bears housed on the property. Two keepers ignored his advice; both had to be pried from the clutches of the bear and suffered “severe” injuries.


Not all of the Zoo’s attractions are feathered or furred. The Rocking Stone sits near the World of Darkness exhibit and packs 30 dense tons into a formation standing 7 feet tall and 10 feet wide. The boulder was carried by glaciers in the last Ice Age. The “rocking” label came from the fact that the stone was so perfectly balanced that it could be moved with slight pressure. The Zoo, fearing someone might one day push it too far, eventually shored up the base to keep it on firmer footing.


The kihansi spray toad was in dire circumstances in 2009: A hydroelectric dam in Tanzania had dried up mists showering a five-acre area near Kihansi Gorge, the toad's only known micro-habitat, and the species was officially declared extinct in the wild. Fortunately, Tanzanian authorities had seen the situation coming and allowed the Bronx Zoo to come in and obtain 499 toads to bring back to America. A portion went to the Toledo Zoo; both facilities spent nearly a decade breeding them in a captive assurance population. The Zoos replicated their habitat while Tanzania created a gravity-operated misting system that would restore water. Roughly 100 toads were returned in 2010 as test cases; a full-scale reintroduction followed in 2012.


A photograph of an Egyptian cobra

Animal escapes have been few and far between at the Zoo. One of the most publicized was the the disappearance of a 20-inch venomous Egyptian cobra in 2011. Zoo officials weren’t certain how the reptile broke out of her habitat, but felt confident she would remain in the building. She did, and was found after a week’s search. In the interim, someone on Twitter engaged 203,000 followers with the freed snake’s fictional exploits. It’s still tweeting.


In 2016, the Zoo was recognized by Guinness World Records as having the largest displayed collection of origami elephants in the world: 78,564. The display, which was briefly open to the public, was intended to draw attention to the plight of the creatures and their poaching rivals through their 96 Elephants campaign meant to stop the trafficking of ivory. The Zoo is down to just three live elephants, and has vowed not to acquire any more once they pass. On August 3, 2017, Zoo organizers plan to crush two tons of ivory in Central Park as part of the awareness campaign.


A shovel is stuck in a pile of fertilizer

With thousands of daily visitors, the Bronx Zoo could probably make use of its own sewage system. Instead, the park unveiled an eco-friendly restroom on park grounds in 2006 that captures human waste and diverts it into compost. The system, which uses only six ounces of water per flush, is estimated to save a million gallons of water a year.

Want to learn more about the Bronx Zoo? Catch The Zoo, a documentary series now airing on Animal Planet. New episodes premiere in February.


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