10 Body-Snatching Parasites

Hans Hillewaert, Wikimedia Commons // CC BY-SA 4.03
Hans Hillewaert, Wikimedia Commons // CC BY-SA 4.03

There are a lot of parasites out there. Some estimates suggest that as many as half of all the species on earth live inside—and feed off—other species. One new study published online (which hasn't been peer reviewed yet) argues that the parasitoid wasps might be the largest single group of animals—a title generally thought to be held by beetles.

Practically every species has its own set of parasites, and even parasites have parasites. In many cases, a parasite's host is little more than a habitat where it can eat and breed. But some parasites have gone a step further, evolving ways to manipulate their hosts in ways that give the parasite a better shot at growing up and spreading its young far and wide. Their methods can be as deliciously gross as the worst imaginings of horror movie screenwriters. Here are 10 examples to inspire new terrors of the silver screen.

1. JEWEL WASP // AUSTRALIA, PACIFIC ISLANDS


The jewel wasp Ampulex compressa is iridescently beautiful, but it's a nightmare for the American cockroach. When a pregnant female wasp gets hold of a roach, she temporarily paralyzes its muscles with a sting, then threads her stinger up into the roach's brain, injecting a cocktail of chemicals that turn the roach into a zombie. The roach could move when the paralysis wears off, but now it doesn't want to. Instead, it allows the wasp to gently lead it by one antenna to her burrow, where she walls it in with one of her eggs. That egg will soon become a larvae that spends its first week on earth eating the living roach bit by bit before pupating and emerging as a wasp to continue the cycle.

2. NEMATOMORPH HAIRWORM // EUROPE

Everything seems normal for weeks after a long-horned grasshopper has drunk water containing the microscopic larvae of the hairworm Spinochordodes tellinii, but that changes as soon as the worm grows big enough to start yearning for a mate. That's when it secretes chemicals that change its host's brain chemistry, making deep water seem enticing to the insect. The grasshopper suddenly has a suicidal urge to take a long hop off a short pier, and as it drowns, the worm—now as much as three times as long as the insect it lived in—squeezes out of its host and swims off to find a mate. Other hairworm species prefer praying mantises or spiders as hosts, but it's the same endgame for them all.

3. PARASITIC BARNACLE // MARINE COASTS

Sacculina carcini
John Aplessed, Wikimedia Commons // Public Domain

A female Sacculina carcini starts its life like any other barnacle—as a tiny planktonic baby floating free in the ocean. But unlike your average barnacle, when she drifts onto a crab she doesn't just settle down and become a warty bump riding on its shell. Instead, she burrows into the crab and grows until she infiltrates every crevice of the crab's body. This can take years, but eventually she's big enough to inflate her bulbous reproductive structures through the crab's abdomen so microscopic males of her species can fertilize her eggs. Once that happens, her crabby host stops molting and growing; all it does is eat and take care of its parasite. Her babies are incubated inside the crab's abdomen, and since part of her is inside the crab's brain by now, she also hijacks its egg-caring behaviors—even male crabs nurture them—to aerate and disperse thousands of her own future mind-controlling brood.

4. ICHNEUMOID WASP // NORTH AMERICA

ichneumoid wasp
MirandaKate, Flickr // CC BY-NC 2.0

A female ichneumoid wasp Campoletis sonorensis sneaking up on a grazing caterpillar isn't looking for a meal for herself—she's shopping for a nose-to-tail larder for her young. The wasp injects one or two fertilized eggs under the caterpillar's skin, and just for good measure, squirts in a virus that will keep the caterpillar's immune system from attacking the invaders. When she flies away, the caterpillar goes right back to eating, but it's a dead grub walking: In a few days, the wormlike wasp larvae hatch inside the caterpillar. They'll spend a couple of weeks munching away at its guts until they grow large enough to burst through its body wall. Then, they spin cocoons—often beside or on the dead body of their host—and pupate into another generation of chest-busting parasitoids (which, unlike most parasites, always kill their hosts).

5. GREEN-BANDED BROODSAC FLATWORM // EUROPE AND NORTH AMERICA

A land snail's eyestalks are normally a pretty drab affair, but that all changes if the snail licks up bird droppings infected with larvae from the flatworm Leucochloridium paradoxum. The baby worms move into the snail's digestive gland, forming an asexual colony that can eventually make up a quarter of the snail's mass. As the colony matures, it starts packing members into bright green, squirming brood sacs that writhe up into the snail's eyestalks, swelling them into fat approximations of wriggling caterpillars. If that's not enough to grab a hungry bird's attention, those pulsing, writhing brood sacs can also break through the snail's body wall and crawl off to mimic a juicy grub on their own.

6. PHRONIMA AMPHIPOD // DEEP OCEAN WORLDWIDE


Freshwater and Marine Image Bank, Wikimedia Commons // Public Domain

The deep-sea amphipod genus Phronima is a literal body-snatcher. This parasitoid captures gelatinous salps—jet-propelled, filter-feeding planktonic animals that are closely related to vertebrates—and hollows them out with jaws and claws, consuming the salp's brain, gills, stomach, and muscles, and scraping its inner walls smooth. The salp body—technically still living—becomes a barrel-shaped, ocean-going home that the amphipod can maneuver like a miniature submarine. It might eventually be a full house, too—female Phronima keep their young in the barrel and care for them until they've grown.

7. RIBEIROIAN TREMATODE FLATWORM // NORTH AMERICA

deformed pacific chorus frog infected with ribeiroia ondatrae parasite
Brett A. Goodman, Pieter T. J. Johnson, Wikimedia Commons // CC BY 2.5

The horror starts when larvae of the parasitic flatworm Ribeiroia ondatrae leave the snail they used as a nursery and burrow into the tail of a bullfrog tadpole. When the tadpole metamorphoses into an adult frog—a period of time that varies between species—the flatworms form cysts around its developing legs, disrupting their growth in ways that damage or double them. The crippled, flatworm-infested frog can't jump away from predatory birds like herons, which gobble them up. The flatworm then spreads to new waterways wherever the bird poops.

8. GALL WASP // WORLDWIDE

gall wasp eggs
Justin 0 of 0, Flickr // CC BY-NC 2.0

Not even plants are safe from parasitism. Females of Cynipidae, the family of gall wasps, lay their eggs inside leaves or under bark, and their larvae make the plant cells surrounding them grow faster than they would normally, effectively forcing the plant to grow them a house. Weird, nonleafy shapes rise up out of the plant, filled with juicy nutritious tissues that feed the wasp larvae and surrounded by tough woody walls that protect it until it becomes an adult (more than a year in some species) and chews its way out of its safe space.

9. ENTOMOPATHOGENIC FUNGUS // NORTH AMERICA

goldenrod beetle infected by mind-controlling E. lampyridarum fungus
Steinkraus et al. in Journal of Invertebrate Pathology, 2017

Goldenrod soldier beetles depend on the family of flowering plants commonly known as asters, which includes goldenrods and daisies. The beetles eat the plants' pollen and mate in their shade. But if a beetle gets infected with the fungus Eryniopsis lampyridarum, it climbs up an aster's stem, clenches the base of a flower with its mandibles, and dies. Within a day, the fungus forces the dead beetle's wings open to expose its spores, which rain down on the hapless beetles below.

10. OPECOELID TREMATODE FLATWORM // PACIFIC MARINE REEFS

Coral colony infected by trematode Podocotyloides stenometra
Alamy

The tiny polyps that build stony corals are usually an inconspicuous brown. But that changes whenever a polyp inadvertently grabs a young Podocotyloides stenometra flatworm for a meal. Somehow, the trematode worm doesn't get digested—instead, it invades the polyp's tentacles, swelling them and turning them bright pink. The color is a bright billboard advertising deliciousness to butterflyfish on the reef, who eat the flashy polyps and spread the worm to other corals across the reef.

Divers Swim With What Could Be the Biggest Great White Shark Ever Filmed

iStock.com/RamonCarretero
iStock.com/RamonCarretero

New pictures and video taken by divers show what could possibly be the largest great white shark ever caught on camera, CNN Travel reports.

Deep Blue, a 50-plus-year-old great white first documented 20 years ago, was spotted off the coast of Hawaii recently in a rare close encounter. Divers were filming tiger sharks feeding on a sperm whale carcass south of Oahu when Deep Blue swam up and began scratching herself on their boat. They accompanied the shark in the water for the rest of the day, even getting close enough to touch her at times.


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"She swam away escorted by two rough-toothed dolphins who danced around her over to one of my [...] shark research vessels and proceeded to use it as a scratching post, passing up feeding for another need," Ocean Ramsey, one of the divers, wrote in an Instagram post.


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Deep Blue is roughly 20 feet long and weighs an estimated 2 tons—likely making her one of the largest great whites alive. (The record for biggest great white shark ever is often disputed, with some outlets listing an alleged 37-foot shark recorded in the 1930s as the record-holder.)

Deep Blue looks especially wide in these photos, leading some to suspect she's pregnant. Swimming so close to great whites is always dangerous, especially when they're feeding, but older, pregnant females tend to be more docile.

Though great white sharks are the largest predatory sharks in the ocean, sharks of Deep Blue's size are seldom seen, and they're filmed alive even less often, making this a remarkable occurrence.

[h/t CNN Travel]

The Psychology Behind Kids' L.O.L. Surprise! Doll Obsession

Jack Taylor, Getty Images
Jack Taylor, Getty Images

Isaac Larian, the founder and CEO of toymaker MGA Entertainment, is an insomniac. Fortunately for him, that inability to sleep forced him to get up out of bed one night—a move that ended up being worth $4 billion.

Larian’s company is the architect of L.O.L. Surprise!, a line of dolls with a clever conceit. The product, which retails for about $10 to $20, is encased in a ball-shaped plastic shell and buried under layers of packaging, forcing children to tear through a gauntlet of wrapping before they’re able to see it. The inspiration came on that highly profitable sleepless night, which Larian spent watching unboxing videos on YouTube. It resulted in the first toy made for a generation wired for delayed gratification.

The dolls first went on sale in test markets at select Target stores in late 2016. MGA shipped out 500,000 of them, all of which sold out within two months. A Cabbage Patch Kid-esque frenzy came the following year. By late 2018, L.O.L. Surprise! (the acronym stands for the fancifully redundant Little Outrageous Little) had moved 800 million units, accounted for seven of the top 10 toys sold in the U.S., and was named Toy of the Year by the Toy Association. Videos of kids and adults unboxing them garner millions of views on YouTube, which is precisely where Larian knew his marketing would be most effective.

A woman holds a L.O.L. Surprise doll and packaging in her hand
Cindy Ord, Getty Images for MGA Entertainment

The dolls themselves are nothing revolutionary. Once freed from their plastic prisons, they stare at their owner with doe-eyed expressions. Some “tinkle,” while others change color in water. They can be dressed in accessories found in the balls or paired with tiny pets (which also must be "unboxed"). Larger bundles, like last year’s $89.99 L.O.L. Bigger Surprise! capsule, feature a plethora of items, each individually wrapped. It took a writer from The New York Times 59 minutes to uncover everything inside.

This methodical excavation is what makes L.O.L. Surprise! so appealing to its pint-sized target audience. Though MGA was advised that kids wouldn’t want to buy something they couldn’t see, Larian and his executives had an instinctual understanding of what child development experts already knew: Kids like looking forward to things.

Dr. Rachel Barr, director of Georgetown University’s Early Learning Project, told The Atlantic that unboxing videos tickle the part of a child’s brain that enjoys anticipation. By age 4 or 5, they have a concept of “the future,” or events that will unfold somewhere other than the present. However, Barr said, they’re also wary of being scared by an unforeseen outcome. In an unboxing video, they know the payoff will be positive and not, say, a live tarantula.

L.O.L. Surprise! is engineered to prolong that anticipatory joy, with kids peeling away wrapping like an onion for up to 20 minutes at a time. The effect is not entirely novel—baseball card collectors have been buying and unwrapping card packs without knowing exactly what’s inside for decades—but paired with social media, MGA was able to strike oil. The dolls now have 350 licensees making everything from bed sheets to apparel. Collectors—or their parents—can buy a $199.99 doll house. So-called “boy toys” are now lurking inside the wrappers, with one, the mohawk-sporting Punk Boi, causing a mild stir for being what MGA calls “anatomically correct.” His tiny plastic genital area facilitates a peeing function.

Whether L.O.L. Surprise! bucks conventional toy trends and continues its popularity beyond a handful of holiday seasons remains to be seen. Already, MGA is pushing alternative products like Poopsie Slime Surprise, a unicorn that can be fed glitter and poops a viscous green slime. An official unboxing video has been viewed 4.2 million times and counting.

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