Phorid Horror

There are many ways to enter this humble world of ours. Some are more dramatic than others, but not many can surpass the entrance of a young phorid fly for sheer triumphant drama.

In this sequence of photos (via National Geographic) you'll see a female phorid fly hovering over a fire ant, who gets pierced by her needle-sharp ovipositor. The egg now planted inside the ant will soon hatch, and the larva will migrate to the ant's head, where, over the course of a few weeks, it will suck up the ant's brain. What is left of the ant after all this? A zombie ant, of course.

The phorid fly larva then commandeers the ant, and can even force it to wander away from the ant hive to protect the ant from the other ants who might begin to get suspicious of the zombie ant. Once in seclusion, the larva pops off the ant's head and proceeds to emerge. How's that for drama? The insect world provides us with horror stories better than most human minds can conceive.

Thanks for the article, Moneca.

Parasitic Harbinger of Good News

It's often all a matter of perspective and context. If I were taking a pleasure stroll along one of my favorite waterways and stumbled across a dead eel thing with a gnarly set of teeth, my day would be ruined. But such was not the case for a volunteer cleanup crew working on the shores of the Thames River.

What Oscar Bridge discovered turns out to be a recently deceased sea lamprey, a parasitic fish that predates the dinosaurs. The fact that it was dead was of no concern, since these fish die after they spawn. That it was found in the Thames is considered to be fantastic news (unless you're a sea lamprey host).

Not long ago the Thames was so polluted that it was considered to be "biologically extinct." But thanks to a variety of efforts, it is now considered to be one of the cleanest city rivers in Europe. Ergo, the return of a sea lamprey to these waters is a very good sign. After all, lampreys are picky spawners: they only enter water they consider to be clean. Picky, picky.

These parasites were once considered to be delicacies (of course). In fact, King Henry I is reputed to have died from eating too many of these. I think one would be enough to do me in.

Thanks for the link, anonymous.

Photos via BBC News

Damsel in Distress

This damselfly was already having a bad day when it came to a spider-iffic end. And there's no Prince Charmingfly that'll come along and rescue it.

Steve, who took this photo, discovered that the poor damselfly was already infested with mite larval sacs, which are the pomegranate seed-like knobs at the base of its wing. I wonder what the spider will think of the sacs when he comes across them. Maybe a bit of dessert? Maybe a little bit of mite infestation for him?

Medicinal & Disciplinary Leeches

Steve was hiking the Beaver Trail just outside Ottawa, Canada, when he saw this leech swimming across open water. So he leaned out over the wooden bridge he had been crossing and snapped this shot.

There are over 600 identified species of leeches in the world, but only 15 are used in medicine. They've been used for such purposes since ancient times, and are still used very effectively to treat abscesses, painful joints, glaucoma, myasthenia, and to heal venous diseases and thrombosis, to name a few.

I intend to use them to discipline my children. Letting a few of these loose in the bath water might teach the kidlets to clear their plates after supper.

Thanks for the photo, Steve.

Tick Trio

Judy sent along this slideshow from WebMD. Want to see what some of the most commonly encountered bugs and their bites look like? Then peruse the gallery. You'll feel itchy, be jumpy, and be more educated once you've done so.

You're looking at a trio of deer ticks. These parasites are diminutive (the average adult is the size of a sesame seed -- think of that the next time you're eating a Big Mac), but you still need to be on the alert. These ticks are vectors for the bacteria that causes Lyme disease.



















I've never had ticks myself, though I once de-ticked a wild skink I caught. That was fun for a wee lad, as it involved fire (a blown out match, which I've since learned isn't the best way to rid oneself of ticks), a reptile, and blood (the ticks made a slight popping noise when I smashed them). And I got a warm-fuzzy feeling from being able to release a skink back into the wild that was better off for having met me. Not every lizard met the same fate (quite a few alligator lizards snapped off their tails in protest of my handling of them), but I'm sure that skink still tells its grandkids about that time when a grubby boy-hand plucked it from its basking rock and used flame to take away its hurt.

Blood-filled Barnacles

Morgan saw that I had been on a spree of posting on marine parasites and predators, and so thought to add some more ugly to the salty stew.

You're looking at what is described as "red, sausage-sized structure [which] is the external portion of an unusual, parasitic barnacle, Briarosaccus callosus." Charming. These barnacles, which turn red as they become engorged with crab their own hemoglobin (thanks for the correction, anon3), render their hosts sterile, use the crab's energy to produce swarms of baby parasitic barnacles, and can even induce the crab to protect the barnacle and assist with larval release.

Photo source: Tom Shirley via NOAA





















The only danger I've ever thought of in association with barnacles is the occasional knee or palm scrape I get when I clamber about tidal pools. But then, my experience has been limited to benign barnacles (a possible band name), and I'm not a crab. I can't imagine what it would be like to have a blood-filled barnacle sticking out of my belly button and telling me what to do. Suddenly ticks and lice don't seem so bad.

Thanks, Morgan. And good luck with your BA thesis.

Long-lived Leech

I'm having a hard time digging up much detail on Pontobdella muricata linnaeus, a marine leech. But it's looking like they feed of the gills of their hosts, and once engorged with blood, they politely disengage and drift away. One source says they can then go upwards of 18 months without feeding again.

I'm not happy with the existence of such long-lived leeches, though I have no idea how long leeches live in general. But there's some silver lining to be found in the fact that they don't need to feed that often. That must be some consolation to their oceanic hosts.

Thanks for the link, Ida.

Photo source: IMARES via World Register of Marine Species,

A Lousy Affair

This poor fish has an infestation of sea lice, and he doesn't look to be doing well. Many dozens of species of fish in the cold waters off Norway's coast are infected with them, and many experts are concerned about how the infestation will spread from wild populations to farmed stock.

I had lice twice while I was in elementary school, and the worst of it was the itching and the treatment (a scalp soak in cod liver oil). But I couldn't imagine what my horror would have been if my eight-year-old scalp had been beset by parasites proportionally as large as these...



















...or if I were to look one in the face and see this staring back at me (color added to electron microscope image to freak you out). Do they have to look so hunched over and eager to suck out my juices?

Photo source: Kevin Mackenzie























Once again, I've been blessed to have been raised in a temperate climate, largely free of significant parasites, and that I'm not a Norwegian fish.

Thanks for the links, Rebecca.

Eye of the Beholder

STOP!

STOP!

Stop right there. Don't go any further. Some things can't be unseen. You're brain isn't a hard drive from which you can permanently erase images. These images will sear into your neocortex, much to your eyeballs' dismay. Scroll down to find out why. But if you don't want to know why and you want to see previous posts, close your eyes and give your mouse wheel a few rotations, or press that Page Down button a few times. You'll be safe.

If you want to read on, you proceed at your own risk.

****

Behold the parasite known as the African Eye Worm. Yes, that's a parasitic worm in that poor soul's eyeball.

Read this Wikipedia article (link above) for all the gory details, but suffice it to say that the vectors for this parasite include bites from the horse, deer, and mango flies, and that you don't want this infection.





















...and you don't want this treatment...





















I've been denied the use of photos by offended photographers who say that all of nature is beautiful, not ugly. Well, I guess ugly truly is in the eye of the beholder (pun intended).

Thanks again, Becca. My eyes itch now--my one consolation: I've never been to West Africa.

Falling Ticks

David Pearson removed this from a patient's ear. It's most likely Dermacentor variabilis, an American dog tick. You can even see a scrap of the ear canal that got removed along with the tick.

Ticks are very common disease vectors, meaning that, like the mosquito, they are responsible for carrying a variety of illnesses from host to host. If you end up with a dog tick in your ear, perhaps you'll be relieved to know that while you might contract Rocky Mountain spotted fever, you won't get Lyme disease. That's carried by the deer tick. I imagine in such a situation, you'd scramble for any form of solace.

It's also a relief to know that ticks don't fly or jump. They usually just fall. Sounds a lot like my son, who's just learned how to walk. No one tell him that I compared him to a tick.

Photo source: David Pearson

Guess I'll Go Eat Worms

WARNING: This post is not for the faint of heart. If you're pregnant, post-partum, intestinal-fortitude-challenged, or just plain ol' squeamish, you may want to bypass this post and head straight for the baboons and birds below.

Now that you've been warned, let's hop aboard the Parasite Express and take a tour of the human body, as abused by the roundworm known as Ascaris lumbricoides.

Here are some tame photos of this parasite, brought to us by Amy. I don't suggest doing an image search for this creature. They aren't pretty.

Photo source: carage.org.lb


















They don't look so menacing when placed beside a ruler. But when placed inside your system, you get a whole different story. If I may quote Amy: after contracting them (by coming in contact with infected feces),

The eggs hatch in your intestine, penetrate the intestinal wall and travel in the blood stream to your liver. From the liver, they travel to the lungs, where you cough up the tiny larvae and re-swallow them. This is how they reach your intestines again, where they attach and mature to the adult stage. Adults grow up to 35 cm long and can shed up to 250,000 eggs a day, which are passed in the feces.

Photo source: Portalesmedicos.com




















...nobody likes me, every body hates me, guess I'll go eat worms...

Oh, but that's not all. Amy has more to share:

One person may be host to hundreds of these worms, and when the worms are threatened by bodily defenses like fever, or by medications, they can begin to migrate. Migration can cause blockage of the intestines, where they bunch up, or they can try to exit the body from the anus or mouth/nose.

And don't think you North American readers are safe from this parasite, which seems like it should only dwell in the deepest regions of the tropics. No, they are prevalent in the Appalachian mountain region.

Now, go wash your hands.

On a lighter note, Amy has something far nicer to share. She's a terrific painter. Check out her portfolio.

Thanks Amy. How can one woman be such a harbinger of ick and beauty?

One Less Worm

What's this? Good news? Yes. It turns out that thanks to a variety of eradication efforts, time, materials, and education, Guinea worm infections are at an all-time low (assuming President Carter can be believed...)

This parasitic worm is being drawn out of a child's foot by a clinic worker in Savelugu, Ghana. Guinea worm (Dracunculiasis) infections are nasty deals, caused by imbibing small water fleas that are in turn infected with worm larvae. When the flea-born larvae enter the human body, they grow, sometimes to a length of three feet. When they finally emerge into the big, blue world, it is through a festering blister on the person's skin.

Thanks to all those workers who have fought this parasite. I'm sure a purist out there will say that the Guinea worm plays a vital part in some section of the African ecology, but that's little consolation to children such as this one. The world can do with one less parasitic worm.

Photo source: AP Photo/Olivier Asselin via Yahoo!

Cosmic Dessert

This harvestman is having a bad day. Not only is he often mistaken for a spider, but he has only a single pair of eyes, his legs (which function as sensory organs in their own right) are prone to falling off, he has no venom, no silk glands, has to molt every ten days, and he's often lost in the shuffle of a possible 10,000 different species of harvestmen. But that's all in a day's work. What's really bothering this arachnid are those red parasites (I'm thinking they're mites).

As I look at this photo, I realize that if I were to come back to this planet as some other life form, probably the worst thing I could come back as is a parasite who feeds off of spiders and their kin. I can't imagine having to have my mandibles buried inside a harvestman's carapace all day long, siphoning off its juices. That's a cosmic dessert I don't wish to be served.

Thanks for the photo, Rick. I'm going to go do some really good deeds today.

UPDATE: Based upon the comments, this might be an instance of phoresy -- the benign insect equivalent of hitch hiking, rather than parasitism.

Death by Horsehair Worm

What you're looking at below is a handful of adult horsehair worms. You'll see that they vary quite a bit in length and color, but all have the appearance of wriggling, coarse hairs or wire.

But it's not the adults that are so fascinating. It's their life cycle before reaching maturity that is the most intriguing.

Photo source: Texas A & M






















The next time you see a beetle or a grasshopper floating dead in the water, don't assume it was a case of a simple drowning. In fact, in the case of the potato bug, more often than not it was murder (cue screechy stabbing noise...)

The young horsehair worm begins life as an egg that is ingested by a hapless insect. The egg then hatches, and the little worm grows inside its host in typical parasite fashion. But the worm doesn't stop there. No, it will settle for nothing less than the death of its host. And it does so by causing the host to drown itself, so that the matured worm(s) might burst forth into the water just in time to mate.

Wow, murder, betrayal, mating. This has all the hallmarks of a good soap opera.

Thanks for the horsehair worm, Rae.

Hematophages

Mosquitoes come in all shapes and sizes and species. Not all drink blood. Not even those that do drink blood do so for their own survival. Rather, the female hematophages (blood drinkers) do so to supplement their need for protein and iron in an effort to spawn still more mosquitoes.

Here is one such instance. See her ram her siphon into the human's skin and tank up? All that blood is human blood. It's because of this blood drinking, and the attendant spread of blood-borne pathogens, that mosquitoes are responsible for the death of more humans in world history than any other animal.

Mosquito photos: venwu225




















You can swat 'em. You can fumigate 'em. You can even enlist the help of members of the Toxorhynchites, the largest extant mosquitoes out there. These mosquitoes don't drink blood; they prey on other mosquitoes. But you can always count on spiders. They seem to have the last word in a lot of these discussions.

Spider photo: Brian Valentine
(bye bye, little midge)

Zombie Spiders

Want to read an article that will have you leave you squirming? Then check out this link, brought to us by Casey. It shows how in nature there are parasites, and then there are parasites who up the ante. And the world is more zombie-rich for it.

Behold the alien beauty (I'm stretching here, for the sake of this post) of a Costa Rican orb weaver known as Plesiometa argyra. This spider is known for its perfectly symmetrical and round webs.



















Ah, but what happens when a parasitoid wasp comes along and stings the spider? The spider goes comatose for about 15 minutes and wakes up and resumes its normal routine. But the spider is unaware that the attack it just *survived* resulted in it being inject with a wasp egg.

A little while later, that same little waspling will hatch and begin dining on the spider. Typical parasite behavior--until it gets time for the little larvae to pupate. It enlists the spider's help in that, by making it a zombie. The larvae hijacks the spider's brain and induces it to ply its web-weaving skills at pupae making. The orb weaver literally spins a cocoon for the larvae and suspends it above the forest floor, safe and out of the way of would-be predators. See the photo below: the left is of a normal web, the right is a zombie web.














And what does the larvae do to show its appreciation? It drains the spider dry and tosses aside its shriveled carcass. I'm afraid that's what my kids will do when they've used me up. I've already got a head start on the zombie thing after a couple of weeks of sleep deprivation.

Body-snatching Barnacles and Zombie Crabs

I stole the title to this post because I loved it so much (and I couldn't think of something better). Turns out not all barnacles are conical-shelled crustaceans that began life as free-floating plankton. Some barnacles are the scourge of any crab they encounter.

When the female Sacculina barnacles invades a crab's body, she does so in an amorphous gelatinous form. She then sends roots throughout the crab's body and begins to feed on it while she grows into a tumorous growth. She even carves out a little spot (the barnacle equivalent of a studio apartment) for the male Sacculina so that she might have baby Sacculinas. But the barnacle doesn't stop there.

Photo source: hku.hk
She seizes control of the crab's mind and forces it to do her bidding. The crab ceases to grow and looses the urge to mate. Instead, it unwillingly devotes itself to caring for the barnacle's eggs, using all of its time and resources to do so (disciplining the barnacles youngsters when they get rowdy, reading to them, singing lullabies just before nap time, etc.). The barnacle even alters the physiology of a male crab so that it becomes a female, so that it might better tend to the eggs.

Come on. I know all creatures need to make a living, but some just take it too far. Some parasites manage to be beneficial, and some become tongues. This one just owns its host in every conceivable way and then discards it. My neighbor has a mooching, parasitical son, who I now suspect might be a variant of the Sacculina barnacle.

Thanks for the link, anonymous.

Louse Tongue

Cymothoa exigua has the dubious distinction of being one of the only parasites on the planet that actually replaces one of the host animal's organs.

Upon entering the spotted rosesnapper's mouth, the nubile sea louse attaches itself to the fish's tongue and starts feeding off the tongue's blood. As C. exiqua grows, the tongue atrophies and falls off. But the sea louse remains, firmly grasping the stump of the tongue. The fish is actually able to move and use the sea louse as if it were its own tongue, and sustains no additional harm.

From what I've read, C. exigua only latches on to the spotted rosesnapper's tongue. How does such a specific parasitism arise? Are they too good for other fish? Is there something extra fancy about spotted rosesnapper tongue?

I imagine that when spotted rosesnappers go out on dates, one of the first things they ask each other--certainly before the first kiss--is if they have a sea louse tongue. That might be a deal breaker for some.

Thanks for the photo, Jelo.

Cuterebras

Those of you who enjoyed my previous bot fly posts will love this next one. Megan is a biology student who is earning her keep at a veterinary clinic. About a month ago she had to deal with a rash of cuterebra cases in dogs.

Cuterebras are but one iteration of the bot fly. What's a bot fly?

Photo source: Brittanica
Well, the fly itself is harmless. They don't bite or sting. They do vaguely resemble bees, but they have nothing, ecologically speaking, in common with them. You see, a bot fly (a cuterebra in this case), lays its eggs along the paths or around the dens frequented by small mammals (dogs, cats, squirrels, rabbits, etc.). The hapless animals then either rub up against or ingest the eggs, which then hatch. The newly spawned bot fly larvae travel to a spot just beneath the skin and form a 'nodule'.

These nodules can be sizeable, since the larvae which inhabit them can get upwards of two-inches long. The larvae have cutting teeth that they use to cut a little hole on the outside so they can breathe. Look up 'bot fly' on YouTube for videos of them in people's backs. You won't be the same afterwards.

Photo source: unknown




















If you find a squirrel with cuterebra nodules, don't worry. The larvae will drop out within 30 days and pupate on the ground. The nodule will heal up. You might not be so cavalier, though, if you get infected. If you do, you'll want to cover the hole with petroleum jelly, which will cause the larvae to emerge for fresh air. Then you can grab it with tweezers. But don't squeeze too hard. If it pops or crumbles inside your skin, it can trigger an infection or even anaphylactic shock.

Ugly, people. Ugly. Thanks, Megan.

Tick Tock

Some time ago, when I had to scrounge for photos and beg permission to use them, I was rebuffed by some wildlife photographers who said that there are no ugly animals. That all of nature was beautiful, and therefore I could not post their photos on a site called Ugly Overload. I would respond by saying that my site isn't a freak show; it is but one humble attempt to restore balance to the blogosphere. After one such rebuke, when a photographer wouldn't let me post on his hamadryas baboon, I posted on a tapeworm to prove that nature could be ugly.

The tick is still more proof. So I revel in posting on it.

There are many varieties of ticks. All of them suck blood from their hosts. They can't fly or jump. They only scamper and drop--and they do so for blood. How do they know where to find their prey? They seek out heat and/or carbon dioxide.

I actually have a fond memory of ticks. When I was a lad I had captured a skink and placed it in a spare terrarium. For about a week I mistook the black orbs nestled against the skink's ears as some sort of skink ear decoration. But then I realized that those orbs were ticks. With one hand I held the skink secure, and with the other I pressed a just-blown-out match tip to the ticks. One by one, they released their grip and fell to the countertop and began scampering away. But they met a swift end beneath my thumb (a bloody end, as it turned out). I then released the skink in the same place I had found him. For once, a reptile left a boy's care better for the experience. See? How's that for improving reptile-human relations?

Thanks for the photo, Booge (I'm still scratching myself).