So far you lucky readers -- if that’s really what you are -- have been treated to lost nuclear hardware, misplaced biological weapons, an18th century spiritualist and his clockwork ‘God,’ and recently, creatures great and small (mostly small) that can kill you faster than you can read this sentence -- even if you’re a slow reader.
But there’s an even more terrifying, creepy, freaky, disturbing subject we haven’t talked about yet: one that can make even the heartiest, stone-stomached of you clutch your tail-wagging doggies and purring kitties while rocking back and forth mumbling “nature is good, nature is good, nature is good …”
As you’ll soon read, however, even your loving pets can save you from the nightmare that is, more than likely, with you already.
Or, to be precise, living inside you already: parasites.
YouTube has far too many clips of botflies, tapeworms, or pinworms in all their disgusting glory: squirming and writhing from puss-glistening holes in their victims, squirming in the bellies of those unfortunate enough to have become part of their life cycle. But that’s not the worst.
We like to think we’re the masters of our destiny, that “I think I shall do (fill in the blank)” comes only from our minds and wills. But in some cases that’s just not true -- or, perhaps, that’s what the creature living inside me is telling me to say.
Welcome to the wonderful world of not just parasites, but parasites that directly influence or flat-out control their hosts.
Beginning big or at least not microscopic, the emerald cockroach wasp has a very unique, and rather frightening, method of supplying its pupal young with a meal. Like some other insects, the wasp feeds its young living prey: paralyzing the snack and then laying an egg on its still-living body. But the emerald isn’t a very big bug, unlike the monstrous tarantula wasp, so it can’t drag its prey back to its burrow. Instead, the emerald performs a type of on-the-go brain surgery, carefully stinging a roach in a few selected parts of its brain, disabling its escape reflex. The wasp then chews off the roach’s antenna, effectively blinding it. Hijacking the roach’s remaining stub of an antenna, it then leads the still-living and -- if roaches have a form of consciousness -- aware bug back to its burrow where it will be a still-living dinner for its offspring.
Yes, you may shudder. But it gets worse.
You’re just lucky you’re not a snail, especially one that happens to become part of a leucochloridium paradoxum ’s elaborate lifecycle. Beginning as eggs in bird droppings, leucochloridium enters the snail’s body and then proceeds into its digestive tract. After a bit of time there, it develops into a larva – and then things get interesting.
How, you might ask, does leucochloridium go from snails to birds? Well, we know how -- but you might not want to know the answer.
What leucochloridium does is make its way from the snail’s gut to one of its eyestalks. There it causes the stalk to become red and inflamed. But that’s not all. The parasite also distorts the snail’s light perception so that it doesn’t hide from light anymore. So, out in the broad daylight, one eyestalk brightly colored, it becomes a something very much like a grub or caterpillar -- which birds love to eat. So the whole cycle begins again.
Then there’s sacculina, a type of barnacle. It loves crabs, but not in a healthy kind of way. What sacculina does, while in the barnacle’s larval phase, is find a nice, juicy crab and land on it. Then it walks around the unlucky crustacean until it finds an unarmored joint, and injects itself into the crab’s tasty meat. But sacculina doesn’t eat the crab. Oh, no – it’s not as simple as that. After a time in the crab’s body, the barnacle reproduces and reproduces and reproduces some more until it emerges as something a lot like a female’s egg sac.
That’s important, because it’s not just the female crab this happens to. If you should happen to be a male crab then transvestitism is in your future. Sacculina messes with the hormones in the male crab, making it basically a female -- especially appealing to other male crabs. It even goes as far as adjust the male’s behavior so it actually begins to act like a female crab, all to attract a male crab that may or may not have other sacculina parasites to fertilize and keep the cycle going. Once sacculina has you, if you’re a crab that is, then you belong to it. Sterilized, you become nothing but a mother to its eggs. Until you die.
We’re not finished yet -- far from it. Just be lucky you’re not a grasshopper or a cricket. Spinochordodes tellinii (the hairworm) larva finds its way into an unlucky hoppity by being eaten. Once in the bug it grows -- but don’t think the worm just gets bigger. It gets so big that when the adult worm comes out of the cricket it can be four times longer than the bug. It’s how it comes out that’s going to give you the shivers. When it simply has had enough of the bug, having pretty much eaten all of it from the inside, the worm takes possession of the insect’s brain, causing it to single-mindedly hunt out water. When it does, the bug jumps in -- and that’s when the worm erupts out of the host and swims away.
Okay, so it’s not fun to be a snail, or a crab, or a cricket. But what about poor homo sapiens? Please don’t tell me you think we don’t have our own, completely unwelcome passengers. I’ve already mentioned botflies, pinworms and tapeworms. But they are just freeloaders. They aren’t driving the bus that is us like these other manipulative parasites do.
Hold that puppy close, cuddle that kitten -- but maybe not that close. Ever heard of toxoplasma gondii? No? Well you might have but it’s certainly heard of you. In fact I’ll bet dollars to donuts that it’s paying a lot of attention to these words right now. Feel like doing something else? Anything else but reading this?
Maybe that isn’t you. Maybe it’s toxoplasma gondii.
I love kitties. But after reading about toxoplasma gondii I think I’m going to become a dog person. Primarily a cat parasite, gondii’s a protozoa that enters the feline system when the animal eats an infected animal. Once in the system, the protozoa can then reproduce asexually, making life pretty damned easy for itself.
But not for its hosts. Although the protozoa is mostly a cat fancier, it also can infect rats and mice. When it does, it does something rather creepy: it directly screws with the infected animal’s brain, taking out Mickey’s fear of cats. Think about that for a second: not open spaces, not water, not something big and general. Gondii only takes out a mouse’s fear of cats -- making sure it’ll get eaten by one, its host of preference.
Like I said, I really like kitties. But is that really ‘me’ who likes cats? Rats and mice and other warm-blooded creatures can carry gondii. You and I and every other homo sapien are also warm-blooded. I think you see where this is going.
Here’s a number for you: 25%. That’s a rather benign amount until you think of 25% of humans. Especially when I add that it’s been theorized that 25% of human beings may be infected by gondii – a parasite that affects the behavior of its hosts.
Some researchers have suggested that men who have gondii in their systems have lower IQs, are more prone to ‘novelty seek,’ and more masculine. Weirdly, infected women come out with higher IQs.
Then there’s reproduction. Not only do some think gondii changes what we are personality-wise, but its also been suggested that women who are infected have a tendency to give birth to more sons -- and males are more likely to spread the infection.
We’ve lost nuclear weapons, contaminated whole islands with biological devices, created mechanical Gods, and have been killed by very small critters with very nasty venoms. But when you think about parasites, especially certain kinds of parasites, the question then becomes:
Who are ‘we’? And who are you?
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