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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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iStock // Ekaterina Minaeva
Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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Nick Briggs/Comic Relief
What Happened to Jamie and Aurelia From Love Actually?
May 26, 2017
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Nick Briggs/Comic Relief

Fans of the romantic-comedy Love Actually recently got a bonus reunion in the form of Red Nose Day Actually, a short charity special that gave audiences a peek at where their favorite characters ended up almost 15 years later.

One of the most improbable pairings from the original film was between Jamie (Colin Firth) and Aurelia (Lúcia Moniz), who fell in love despite almost no shared vocabulary. Jamie is English, and Aurelia is Portuguese, and they know just enough of each other’s native tongues for Jamie to propose and Aurelia to accept.

A decade and a half on, they have both improved their knowledge of each other’s languages—if not perfectly, in Jamie’s case. But apparently, their love is much stronger than his grasp on Portuguese grammar, because they’ve got three bilingual kids and another on the way. (And still enjoy having important romantic moments in the car.)

In 2015, Love Actually script editor Emma Freud revealed via Twitter what happened between Karen and Harry (Emma Thompson and Alan Rickman, who passed away last year). Most of the other couples get happy endings in the short—even if Hugh Grant's character hasn't gotten any better at dancing.

[h/t TV Guide]