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]

100 Dachshunds Competed in Cincinnati’s Annual ‘Running of the Wieners’

NORRIE3699/iStock via Getty Images
NORRIE3699/iStock via Getty Images

Every year, to kick off Cincinnati’s Oktoberfest Zinzinnati, 100 dachshunds compete in heats to decide who the fastest dachshund in the Midwest is. This year marks the 43rd annual Oktoberfest—one of the biggest Oktoberfest celebrations outside of Germany (more than 500,000 people attend the three-day event).

On the afternoon of Thursday, September 19, 100 wiener dogs (and their owners and handlers) gathered in downtown Cincinnati for the 2019 "Running of the Wieners." The dogs, dressed in hot dog costumes, ran 10 heats, which lasted 75 feet or five seconds each. The winner of each heat advanced to the final round, where the top three finishers were decided.

Maple, a long-haired, one-year-old dachshund, ran his way into first place—and into our hearts.

Maple’s owner, Jake Sander, told WCPO that Maple is one of five dachshunds in the family, and that he learned to run fast by chasing his brother around. Leo and Bucky, two other doxies, placed second and third, respectively.

Besides the Running of the Wieners, Zinzinnati also hosts the World’s Largest Chicken Dance. However, the wiener dogs are more fun to watch.

Photographer Captures Polka-Dotted Zebra Foal in Kenya

Frank Liu
Frank Liu

Zebras are known for their eye-catching patterns, but this polka-dotted foal recently photographed in Kenya's Masai Mara National Reserve really stands out from the herd. As National Geographic reports, the zebra baby likely has pseudomelanism, a rare pigment condition that's been observed in the wild just a handful of times.

Nature photographer Frank Liu saw the zebra foal while looking for rhinos in the savannah wilderness preserve. After initially confusing the specimen for a different type of animal, he realized upon closer inspection that it was actually a plains zebra born with spots instead of stripes. The newborn foal was named Tira after the Maasai guide Antony Tira who first pointed him out.

Zebra foal with spots walking with mother.
Frank Liu

Zebra foal with spots.
Frank Liu

A typical zebra pattern is the result of pigment cells called melanocytes, which are responsible for the black base coat, and melanin, which gives the animal its white stripes. (So if you've ever wondered if zebras are white with black stripes or black with white stripes, the answer is the latter). In Tira and other zebras with pseudomelanism, the melanocytes are fully expressed, but a genetic mutation causes the melanin to appear as dots rather than unbroken stripes.


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Though rare, this isn't the only time a zebra with pseudomelanism has been documented in nature. Pseudomelanistic zebras have also been spotted in Botswana’s Okavango Delta, but Liu believes this could be the first time one was found in the Masai Mara preserve.

Zebra stripes aren't just for decoration. The distinct pattern may act as camouflage, bug repellant, and a built-in temperature regulation system. Without these evolutionary benefits, Tira has a lower chance of making it to adulthood: Pseudomelanistic zebra adults are rarely observed for this reason. But as Liu's photographs show, the foal has the protection and acceptance of his herd on his side.

[h/t National Geographic]

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