This Snake’s Venomous Powers Morph as It Grows Up

Snakes: Ian Macdonald / Art: Rebecca O'Connell
Snakes: Ian Macdonald / Art: Rebecca O'Connell

Our relationship to food changes as we age. Our metabolisms slow. We start carrying antacids when going out to dinner. Sometimes we’ll even intentionally eat vegetables. But our transformation has nothing on the brown snake, whose venom gradually morphs to accommodate its new eating habits. Researchers described the snake’s enviable aging process in the journal Comparative Biochemistry and Physiology, Part C: Toxicology & Pharmacology.

Australian brown snakes (genus Pseudonaja) pack some of the most deadly venom in the world. As the authors of the new paper note, brown snakes are also “responsible for the majority of medically important human envenomations in Australia.” And that's saying something.

To better understand how that venom works, researchers collected samples from adult and juvenile snakes from nine known Pseudonaja species. Then they tested each venom’s effect on blood and other substances.

Eight out of the nine species showed a distinct change in venom action between the snake’s youth and adulthood. Brown snake venom is known for its anticoagulant, or blood clot–preventing, properties, which can lead to deadly strokes in small animals and internal bleeding in humans. But only the grown-ups’ venom contained anticoagulants. The babies’ toxic spit had its own power: attacking the nervous system, causing paralysis.


Juvenile (L) and adult (R) brown snakes.
Snakes: Stewart Macdonald / Art: Rebecca O'Connell

The venom’s transformation over time is not random, lead author Bryan Fry, of the University of Queensland, says, but a brilliant adaptation to the snake’s preferred diet at different stages in its life. Baby brown snakes eat tiny lizards, while adults prefer meatier—but scrappier—mammalian fare like rodents. They need a venom that knocks out their opponents fast.

"Young brown snakes may produce clinical symptoms like that of a death adder, as they seek out and paralyze sleeping lizards,” Fry said in a statement. "Once older, their venom contains toxins that cause devastating interference with blood clotting, causing rodent prey to become immobilized by stroke.”

Within the adult snakes’ venom lay another surprise. Scientists knew that brown snake venom worked by converting one blood protein into another, but other snakes do that, too, and their venom isn’t as fast-acting. Some other, hidden process, was going on, and Fry and his colleagues found it.

"Our team discovered brown snakes are potent in activating Factor VII, another blood-clotting enzyme, which is the missing (dark matter) element of brown snake envenomations,” he said. "The feedback loop created by this enzyme would become a venomous vortex and dramatically accelerate the effects upon the blood."

Reminder: It’s not that brown snakes want to be responsible for medically important human envenomations. Like sharks and bears, they’d much rather be left to go about their business. So the best thing for you, and them, is to leave them alone.

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]

Plano, Texas Is Home to a Dog-Friendly Movie Theater That Serves Bottomless Wine or Whiskey

K9 Cinemas
K9 Cinemas

For dog owners in Plano, Texas, movie night with Fido no longer just means cuddling on the couch and browsing Netflix. The recently opened K9 Cinemas invites moviegoers—both human and canine—to watch classic films on the big screen. And the best part for the human members of this couple? Your $15 ticket includes bottomless wine or whiskey (or soft drinks if you're under 21).

The theater operates as a pop-up (or perhaps pup-up?) in a private event space near Custer Road and 15th Street in Plano. Snacks—both the pet and people kind—are available for $2 apiece. Dogs are limited to two per person, and just 25 human seats are sold per showing to leave room for the furry guests.

Pet owners are asked follow a few rules in order to take advantage of what the theater has to offer. Dogs must be up-to-date on all their shots, and owners can submit veterinary records online or bring a hard copy to the theater to verify their pooch's health status. Once inside, owners are responsible for taking their dog out for potty breaks and cleaning up after any accidents that happen (thankfully the floors are concrete and easy to wipe down).

While many of the movies shown are canine-themed—a recent screening of A Dog's Journey included branded bandanas with every ticket purchase—they also hold special events, like a Game of Thrones finale watch party (no word on how the puppers in attendance responded to Jon Snow finally acknowledging what a good boy Ghost is).

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