No Venom, No Problem: This Spider Uses a Slingshot to Catch Prey

Courtesy of Sarah Han
Courtesy of Sarah Han

There are thousands of ways nature can kill, and spider species often come up with the most creative methods of execution. Hyptiotes cavatus, otherwise known as the triangle weaver spider, is one such example. Lacking venom, the spider manages to weaponize its silk, using it to hurl itself forward like a terrifying slingshot to trap its prey.

This unusual method was studied up close for a recent paper published in the Proceedings of the National Academy of Sciences by researchers at the University of Akron in Ohio. They say it's the only known instance of an animal using an external device—its web—for power amplification.

Hyptiotes cavatus's technique is simple. After constructing a web, the spider takes one of the main strands and breaks it in half, pulling it taut by moving backwards. Then, it anchors itself to a spot with more webbing in the rear. When the spider releases that webbing, it surges forward, propelled by the sudden release of stored energy. In the slingshot analogy, the webbing is the strap and the spider is the projectile.

This jerking motion causes the web to oscillate, tangling the spider's prey further in silk. The spider can repeat this until the web has completely immobilized its prey, a low-risk entrapment that doesn’t require the spider to get too close and risk injury from larger victims.

The triangle weaver spider doesn’t have venom, and it needs to be proactive in attacking and stifling prey. Once a potential meal lands in its web, it’s able to clear distances much more quickly using this slingshot technique than if it crawled over. In the lab, scientists clocked the spider’s acceleration at 2535 feet per second squared.

Spiders are notoriously nimble and devious. Cebrennus rechenbergi, or the flic-flac spider, can do cartwheels to spin out of danger; Myrmarachne resemble ants and even wiggle their front legs like ant antennae. It helps them avoid predators, but if they see a meal, they’ll drop the act and pounce. With H. cavatus, it now appears they’re learning to use tools, too.

[h/t Live Science]

20 Freaky Facts About the Giant Squid

Canadian Illustrated News, Wikimedia Commons // Public Domain
Canadian Illustrated News, Wikimedia Commons // Public Domain

Last week, scientists aboard a NOAA Ocean Exploration and Research ship in the Gulf of Mexico captured video of an elusive giant squid—the first recorded sighting in U.S. waters. In the 28-second clip, the cephalopod emerges from the blackness of the deep sea and attacks an electronic jellyfish. After wrapping its tentacles around the luminescent bait, the squid loses interest and disappears in the murk. Since ancient times, philosophers and naturalists have puzzled over this rarely seen enigma. There’s plenty we still don’t know about giant squid, but we’ve learned a lot over the past 20 years.

1. Giant squid eyes are the size of Frisbees.

Woman next to a preserved giant squid eye
Smithsonian Institution, Wikimedia Commons // Public Domain

A staggering 10.5 inches across, a squid’s eyeballs lack the jelly-like substance that gives ours their shape. Instead, they’re filled with water, which leaks out once the invertebrate dies. "The eyes collapse. It's like a collapsed plastic bag,” biologist Dan-Eric Nilsson told NPR in 2012.

2. Female giant squid are bigger than males.

On average, female giant squid are around twice the size of males from the tip of their beaks to the ends of their two longest tentacles.

3. Giant squid suckers can leave ugly battle scars.

The giant squid's main enemy is the sperm whale. While under attack, the squid often retaliate by inflicting large, circular wounds, courtesy of the serrated rings around each sucker.

4.The giant squid’s maximum length is about 43 feet.

At least, that’s what the available evidence tells us. Reports of 60- and 70-footers have never been verified scientifically.

5. Instead of a proper tongue, they use a radula.

This organ rests inside their beaks and is covered with seven rows of denticles—sharp, toothy, backwards-pointing protrusions.

6. There may be just one known species.

A genetic analysis in 2013 suggested that Architeuthis duxis the only species of giant squid, as revealed by a comparison of 43 specimens from around the world. The giant squid gene pool seemed abnormally shallow—all 43 subjects were pretty much indistinguishable in this regard. “It’s completely bizarre,” geneticist Thomas Gilbert said. “How can something be global but have so little variation?” Other researchers, however, argue that there may be as many as eight Architeuthis species out there.

7. Giant squid tentacles can regenerate.

One giant squid corpse found in Canada in 1968 had a partially regenerated tentacle. According to a study of the specimen in the Canadian Journal of Zoology, "the regenerated club differed in length and width, and in the size and pattern of suckers, when compared with the normal tentacular arm." Many cephalopods besides squid are capable of this feat, including octopuses.

8. An estimated 4.3 to 131 million get eaten by sperm whales each year.

The squid regularly show up inside sperm whale stomachs. Approximately 360,000 of these mammals swim the oceans. So, if every sperm whale on Earth devoured an average of one giant squid per month, that means 4.3 million would be offed annually.

But some experts think this figure is way too low. Every single day, male whales put away 300 to 400 squid of various species, while females consume an outrageous 700 to 800 squid. Should Architeuthis represent even 1 percent of their diet, then the whales eat 3.6 million daily. That’s 131 million giant squid killed annually.

9. Giant squid may have helped give rise to sea serpent legends.

In one of Moby-Dick’s more memorable chapters, an Architeuthis slithers towards Captain Ahab’s whaleboat. Apparently, Herman Melville wasn’t a fan—Ishmael describes the squid as a “vast, pulpy mass” complete with “innumerable long arms radiating from its center, curling and twisting like a nest of anacondas.” But Melville wasn't alone. Many believe that this predator’s writhing, snake-like limbs have long inspired sea serpent yarns.

10. 20,000 Leagues Under the Sea grossly overestimates the giant squid’s usual weight.

Jules Verne’s 1869 masterpiece remains impressive today: his novel predicted the invention of both scuba tanks and taser guns. But there are still a few gaffes to be found, particularly during the book’s most iconic scene. When hordes of giant squid attack, the narrator, a French professor named Pierre Arronax, estimates that each one must weigh “between four and five thousand pounds.” But as far as modern scientists can tell, the heaviest animals weigh around a ton—although most are less than 1000 pounds.

11. Like all squids, giant squids have three hearts.

A median heart pumps oxygenated blood throughout the body, which it receives from two smaller ones that pump blood through the gills.

12. Architeuthis penises are about a yard long.

Nobody has ever documented a pair of giant squid getting busy. But biologists suspect that males use their sex organs like syringes, injecting sperm into a female’s skin, where she stores the cells until her eggs need fertilizing. When that happens, the mom-to-be pulls them out of storage (though we’re not sure how).

13. The first giant squid photo ever shot was taken inside of a bathroom.

First photo of a giant squid
Wikimedia Commons // Public Domain

In 1873, Newfoundland minister Moses Harvey acquired a dead Architeuthis which he laid out over his shower curtain rod and preserved for posterity. He’d purchased this specimen for just $10 from a few local fishermen who’d ensnared it with their nets while out in Logy Bay.

14. Giant squid might be cannibals.

Bits and pieces of one Architeuthis showed up in a live giant squid's stomach. But this doesn’t necessarily prove that giant squid dine on one another—some scientists speculate that the squid may have accidentally swallowed a few parts of itself somehow.

15. The Smithsonian has two giant squid on display.

You can see them in the National Museum of Natural History’s Sant Ocean Hall. The pair represents both sexes—here’s a quick look at their 25-foot female (it was probably 36 feet while alive):

16. Their brains are donut-shaped.

But that’s not the weird part. What’s truly bizarre (at least from our mammal-centric perspective) is the fact that its esophagus passes through the hole in the middle of its brain. Giant squids have to be really careful while swallowing, because if a given meal isn’t broken down into small pieces first, it can rub against the brain and cause damage.

17. Before 2004, nobody had ever snapped any pictures of a live one …

History was made by residents of the Ogasawara Islands (located 600 miles south of Japan) on September 30, 2004. Using a line baited with shrimp, zoologist Tsunemi Kubodera and whale-watcher Kyochi Mori attracted an Architeuthis about 2950 feet beneath their vessel. Five hundred still images were then snapped by a submerged camera before the squid took off—leaving behind an 18-foot severed tentacle.

18. … And the world’s first giant squid video didn’t arrive until 2006.

Kubodera would top himself that year when his crew videotaped a young female as they dragged her up to the surface. “We believe this is the first time anyone has successfully filmed a giant squid that was alive,” he said. “Now that we know where to find them, we think we can be more successful at studying them in the future.” Sadly, Kubodera’s prize died during the ordeal.

19. Jellyfish help Architeuthis hunt.

They say the enemy of your enemy is your friend. Certain jellyfish are bioluminescent, which means that they can light themselves up and illuminate the ocean’s inky depths. Predators like giant squid eat many of the fish that hunt jellyfish. So, if a bioluminescent jelly finds itself under attack, it can issue a cry for help by flashing a distress signal, in the hopes that it might attract an even larger carnivore and scare off its assailant. That was the theory behind luring the giant squid with an electronic jellyfish, as seen in the recent NOAA video.

20. It’s not the only monster-sized squid out there.

Meet Mesonychoteuthis hamiltoni, better known as the colossal squid. Though Architeuthis probably exceeds it length-wise, M. hamiltoni is heavier on average, has even bigger eyeballs, and wields swiveling hooks on its tentacles. This isn't a creature you’d want to mess with.

11 Tips for Traveling With Your Pet, According to a Veterinarian

iStock/walik
iStock/walik

Planning a trip can be stressful no matter the circumstances. When you want to include the family pet in your plans, you have a whole new list of things to worry about, including packing the right equipment, checking your hotel’s pet policy, and making sure your pet meets the travel criteria for the state or country you’re visiting. But if you’re aware of the steps you need to take, traveling with your pet can be a positive experience for all involved. Mental Floss spoke with Dr. Danielle Bernal, a veterinarian with Wellness Natural Pet Food, about what to keep in mind before hitting the road with your furry companion.

1. Keep pets comfortable in a travel crate.

You may be tempted to give your pet plenty of room on long car trips, but giving them a confined space that’s their own is usually the better option. According to Bernal, “It’s often better for the dog, because if they’re crate-trained, that’s their area of security.” It’s safer as well: An animal is much better off in a durable crate than it is sliding around untethered in the backseat of a car.

2. Don’t fill your pet's crate with toys.

Giving your pet lots of toys to play with at home is a good thing—but on long car trips it's a different story. Packing every toy your pet loves into their crate takes up what little room they have to themselves. If the crate is too full, it can be impossible for them to move around and adjust their position. “Yes, you want them to be comfortable, but also you don’t want to fill that crate up,” Bernal says. “So almost less is more.”

3. Make sure you have all the correct paperwork.

If you’re planning a long trip with your pet, you won’t get very far without the right paperwork. Many places require incoming pets to have an up-to-date health certificate signed by an accredited veterinarian. Before signing the documents, vets will confirm that your pet is healthy and up-to-date on all vaccinations required by the receiving state or country. If you’re flying, contact the airline to see if any other special paperwork is required to transport your animal.

4. Make it easier to find your pet if they get lost.

An unfamiliar location miles away from home is the worst place to lose your pet. Before your trip, make sure they’re easy to find in case the worst happens. Implanting a microchip under your dog or cat’s skin will make them trackable no matter where in the country they wander off to. If you’re not willing to commit to that procedure, at least make sure the contact information on their tags is up-to-date—that way, they're more likely to be returned to satefy if someone finds them.

5. Skip a meal on travel days.

No matter how accommodating you are to your pet, some anxiety on their part is inevitable. Bernal says a common symptom of this is stress diarrhea—which is the last thing pet owners want to deal with on a long car or plane ride. Even if your pet doesn't seem stressed before the trip, plain old motion sickness can upset your animal’s stomach rather quickly. Bernal recommends feeding them less than you usually would prior to traveling to avoid future accidents: “If you have a pet you know has those sensitivities, I would keep their tummy empty. It will be good for the pet and it will be nicer for everyone in the car too.” That doesn’t mean you should starve your pet if they’re begging for food; just skip the last meal you would normally feed them before beginning your journey.

6. Keep your pet hydrated.

Without regular access to water whenever they need it, pets can get easily dehydrated when traveling. Keep this in mind when traveling and pack extra water for your four-legged passenger. Allowing animals to self-regulate their water intake, perhaps by attaching a bowl to the inside of their crate, is ideal, but if that’s not possible, stop frequently to give them a chance to drink. Another way to keep them feeling good is to feed them wet food instead of dry; according to Bernal, the water content in wet food can help hydrate pets.

7. keep them occupied with a toy.

If you can only give your pet one toy on a long trip, choose something that will keep them busy for as long as possible. Bernal recommends puzzle dog toys like those you’ll find from the pet brand Kong. When your dog is preoccupied on reaching the treat inside the toy, it's harder for them to focus on anything else—including the stress of traveling to a new place.

8. Never leave your pet in a car alone.

Hopefully this is common sense for most pet parents, but Bernal emphasizes that this is the most important thing to remember when traveling with an animal—especially during the summer months. “Don’t leave them in a locked car,” she says. “It takes seven minutes for them to basically move into a situation where it becomes fatal.” It doesn’t matter if you crack a window or if you’re only stepping out of your car for a few minutes. If it’s a hot day, dogs should never be left alone in a vehicle. “We need to make sure that all pet parents are aware of that,” Bernal says.

9. Choose pet-friendly accommodations.

You may love your pet, but that doesn’t mean the owner of the hotel or Airbnb where you’re staying will love them, too; be mindful of this when booking accommodations for your trip. There are plenty of hotels that offer perks for pet owners, like doggie daycare, but even if a place doesn’t advertise their pet policy, it doesn’t hurt to call and ask (or simply confirm what you're reading online so that there are no surprises when you arrive).

10. Make your travel destination feel like home.

Your pet’s crate may not be the best place for all their toys, but that doesn’t mean you shouldn’t pack them when going on vacation. Bringing their favorite items from home can make pets feel more at ease when they arrive at an unfamiliar destination. “Pack things that are familiar to them, so when they arrive at a new spot they’re like: ‘Ok, I feel a lot more comfortable,’” Bernal says. “It helps with their anxiety.” And you shouldn’t stop at toys: Packing their bed, bowl, and blanket can have the same calming effect.

11. Know when it's best to leave your pet at home.

Not every vacation is improved by bringing your pet along. If you plan on spending most of your trip in places that don’t allow animals, like museums, restaurants, and theme parks, it may be best to leave your pet at a kennel or with a sitter or trusted friend. Even if the vacation is pet-friendly, it may not be a good fit for an animal that’s especially anxious. “If you have a nervous dog, he’s actually going to be happier in his home if someone just comes in and feeds him,” Bernal says. Your pet will forgive you for having fun without them.

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