Halloween Special: Terrifying Parasites

I sat down recently with my girlfriend to watch Alien - a movie that I hadn’t seen in a long time. As you might guess from my granny-murdering epic on the flight-or-fight response, when I see a good horror movie I think two words: blog article. The classic chest-bursting, cat-rescuing, android-killing sci-fi horror flick got me thinking about parasites and how there were some I know of that are freaky-as-hell. So, in my typical fashion I began to do some research on some of the most incredibly nasty ones I could find.

This article is, quite fittingly for the time of year, not for the faint of heart. Join me as we delve into some of the most stomach-turning little critters that nature has to offer…

Cymothoa exigua

The tongue-eating louse. You would think
the fish would notice... (source)

As you will no doubt be aware, us biology types are really not good at coming up with names for stuff. You might be thinking ‘That doesn’t sound like a very scary creature, Adam – you promised me an H.R. Geiger-esque grossfest!’. Perhaps if I gave it its English name, you might get a picture of just how nasty this wee bastard is – the tongue-eating louse.

‘Ewww’ I hear you say. And right you are. But don’t worry – it doesn’t chow down on human tongues (as far as we know *scary music*) – it likes to dine on fish. The louse enters the body of the fish through the gills and attaches itself to the base of the tongue. This adorable little critter then begins to drain the blood from the tongue through the claws at the front of its body. The tongue eventually shrivels up and the louse attaches itself to the remaining muscles where it actually becomes the tongue of the fish. Perhaps the strangest fact about this relationship is that the fish continues to use the louse as its tongue, suffering no ill effect whatsoever (other than losing their tongue and having it replaced with something out of a Ridley Scott movie). 

Scientists reckon that, despite its horrifying appearance and habits, this parasite is benign. Though I expect if one were to ask a fish suffering from this particular affliction, it might offer an alternate opinion. That somehow brings me on to a worm that can control the behaviour of the host it infects.

Dracunculus medinensis (Guinea worm)

The young guinea worm - I mercifully decided
not to include a photo of the worm hanging out of
some poor dude'sleg. (Source: CDC Public Health Library)

The scientific one for this one sounds somewhat less cuddly – unfortunately the plain English name makes it sound like a long and wriggly but furry and adorable house pet. Unlike the tongue eating louse, this little fella does parasitize humans. D. medinensis shares many physical and behavioural characteristics with most worms that like to be really friendly with humans, but the thing that makes it particularly scary is the way in which it spreads from host to host.

As with most parasites, part of the life cycle of this adorable little worm partly takes place in a second type of host. The parasite larvae are initially eaten by water fleas which are then ingested by humans drinking unfiltered water. The fleas are broken down in the stomach acids of the unfortunate host, leaving behind the Guinea worm larvae. The larvae escape into the stomach lining and intestine where they mature and develop into an adult worm measuring something like two or three feet in length (I know – the more you learn about this thing, the less you like it).

When it comes time for the young worm to ‘sow its wild oats’, it migrates to the surface of the skin – usually in the lower portion of the leg. This is where it gets weird(er). The worm creates a blister on the surface of the skin and induces a burning sensation which causes the host to seek the comfort of some nice cold water. When the blister in question is submerged in order to provide some relieve from the burning sensation, the worm (now poking its wormy little head out of the host) releases its larvae into the water – thus starting the whole unpleasant cycle all over again. 

Ophiocordyceps unilateralis – zombifying

fungus

A victim of O. unilateralis - yes, that
a mushroom growing out of it's head.
(Source: PLoS One)

This one is probably my favourite, is arguably the most disturbing and is definitely the most horror movie-esque.  That’s right folks – this is a parasitic fungus that turns its unsuspecting host into a zombie. Before you start to panic and build a bunker under your house or find a shotgun and team up with a band of rugged survivors, this fungus only works on ants. This is considerably less scary. Of course if they were giant zombie ants things would be quite different. 

Anyway- not much is known about the life cycle of this fungus, but scientists believe that the fungal spores enter the ant’s body and begin to develop, all the while consuming the insect’s soft tissues. During this horrific process, the fungus produces compounds which alter the ant’s behaviour, turning it into a ‘zombie’. When this happens, it begins to convulse and falls out of the tree it usually lives in. After it hits the ground, the ant finds a plant, climbs the stem and clamps itself to a leaf vein with force far in excess of its usual abilities. At this point, the ant dies- but the fungus continues its grizzly work.

The fungus continues to grow throughout the ant corpse, consuming the rest of its soft tissues and structurally reinforces the exoskeleton of the unfortunate victim. The fungus also sprouts outside of the ant where it completely anchors the ant to the plant (hey, look at that – I made a rhyme!). Finally we make it to the nastiest part – when the fungus is ready, a mushroom (or fruiting body) grows out of the dead ant’s head where it releases its spores into the environment.

I imagine we are all too grossed out at this point to enjoy a smart-ass comment, so I won’t make one. Moving on.

Leocochloridium Paradoxum – zombifying flatworm

An infected snail. No, it's not a snail who has seen an
attractive lady snail to it's left. Photo by
Thomas Hahmann

From zombie ants to zombie snails. That’s right – you heard me. Leocochloridium paradoxum is a flatworm more commonly known as a green-banded broodsac- and it’s fairly disgusting. Where this critter really wants to be (its definitive host) is in a bird. Unfortunately birds don’t really like to chow down on a tasty flatworm, creating a significant obstacle for the little fella to overcome.

The flatworm larva hangs about on the ground until it is hovered up by a passing snail – its intermediate host. The flatworm is now presented with a new problem – birds don’t really like to eat snails much either. One thing they do like to eat, however, is caterpillar (I am going somewhere with this, don’t worry).

Inside the snail the developing flatworm migrates to the eyestalks (weirdly, they seem to prefer the left one) where they grow into broodsacs. This process has a dramatic effect on the antenna of the snail – the broodsac causes the stalk to elongate, swell and turn bright green and yellow. That’s right – it makes it look like a caterpillar. Now for the clever part. The infection of the eye changes the snail’s sensitivity to light, causing it to mindlessly seek out light, open areas – which is kind of like lighting up an ‘ALL YOU CAN EAT BUFFET!’ sign for birds flying overhead. 

The poor zombified snail is then eaten by a bird which thinks it has a caterpillar stuck to its head. The flatworm then finishes its development in the bird with its larvae being excreted back to the earth, beginning the whole cycle  all over 

again.

Cotesia Glomerata – the real ‘Xenomorph’

I’ve saved the best for last – this horrible little creature is the real-life inspiration behind the iconic scene from Alien you can’t un-see: the chest-bursting scene. When the writers of Alien were coming up with the scene that would freak out a generation, they looked to Cotesia glomerata- a parasitic wasp. Now, wasps are scary at the best of times- but this one takes the cake.

Thankfully Cotesia doesn’t prey on humans, but is the bane of the white butterfly – giving it its common and vaguely cuddly name of the White Butterfly Parasite. Don’t let the name fool you – this is one nasty little bugger. 

The whole thing starts when the female wasp injects its eggs into the caterpillars of the white butterflies using a needle-like organ called an ovipositor. Over a 14-day period, the wasp embyros consume the caterpillar from within, developing into larvae inside the body of the wasp with the size of the brood reaching up to 50-60, with each larva being about the size of a rice grain. While the larvae develop within the caterpillar its behaviour is altered – it gorges itself, eating 1.5 times its usual food intake to nurture its unwanted passengers.

An interesting little side note here is how the eggs survive when initially injected into their host. Normally when a foreign body enters the circulation of a living organism it is usually neutralised and cleared by the host immune response. In order to overcome this threat, the White Butterfly Parasite eggs are coated in a virus which paralyses the insect’s immune response. The virus is actually genetically coded in the wasp’s DNA.

Anyway, back to the zombified-caterpillar-wasp-incubator. While the larvae are growing inside the caterpillar they are careful not to actually kill the host – only drinking its blood and never damaging the vital organs. This is a characteristic shared by the most effective parasites – they keep the host alive. When their two –week development is up, the larvae are ready to emerge and the scene from Alien begins.

Someone get Ellen Ripley... and tell her to bring a
pulse gun. (source)

The larvae release a toxin which paralyses the caterpillar before burrowing out of their poor victim with their razor-like teeth – just like poor Kane in Alien. Unbelievably, the larvae aren’t yet done with their former host. The larvae themselves begin to spin protective cocoons to safeguard the rest of their development, but that might not be enough to prevent them from being targeted by other parasitic wasps – so they recruit their poor adopted parent to provide an additional layer of protection by coating the brood in the silk that would have normally been reserved for forming its own cocoon. The zombie caterpillar then spends its remaining days defending its adopted brood from the same fate it originally suffered.

You might think it’s no walk in the park being a human being  - but if you imagine you could instead be a snail, an ant or caterpillar living in that park, things probably don’t seem that bad.  

Happy Halloween, internet folks! Remember to like the Facebook page to help support and receive updates from ScienceUnplugged!

As much as these parasites are interesting to read about, parasitic organisms are a huge problem in developing countries where they can be a leading cause of disease and death in humans. If you would like to know more about the issue or donate money to help combat tropical diseases please feel free to check out the Bill and Melinda Gates Foundation, UNICEF and the World Health Organisation.

As with every article I post here, this one has been thoroughly researched and a list of sources can be provided for anyone who is curious – just check out the contact page 

Four space age technologies that already exist (kinda).

Yes, I know. You are all heartbroken because I haven’t posted an article in a while – unfortunately real life gets in the way of the internet. How awesome would it be to live as some sort of digital being floating amongst all the racism and cat pictures like some kind of electronic ghost of internet present?  Sneaking up on people and going “Well well well, what have we here?” when they open a private browsing window?

… anyway, moving on.

This week we bring you some space age technology that (kind of) already exists (a little). I’ll be honest with you, it’s not going to be my best work but I am working on a new article as you read this and it’s going to be a tour-de-force of whimsy and wonderment (It’s really not). As always, any complaints can be addressed to 123 Fake Street. As for the town? Just write down the town you live in and I’m sure it will find its way to me *snigger*.

Okay, let’s do this *cracks knuckles*

*Note: you will notice that, with the exception of the first image, my captions are somewhat lazy - this isn't a lack of creativity, but a fantastic new feature Google have added to their blogging service that makes captions of more than a few words take up several lines of the whole page - thanks Google! Making things easier through innovation!* 

A see-through phone 

 

I don’t know about you, but when I picture the future I see all computer technology being small, sleek, pretty and see-through, if not holographic or built into the brain in some sort of freaky melding of man and machine. If you go into any phone shop today you will notice that more and more advanced technology is being crammed into smartphones no bigger than a few square inches – so we are well on our way to downsizing the helpful technology we use every day.

Its a carrot! Not really, it's a see-through 
phone. (Source: Polytron)

As for the see-through part, a Taiwan-based company called Polytron has recently unveiled a prototype of the hardware of a transparent handset. The phone contains all the hardware you would expect from a modern handset: an expansion card slot, a battery, speakers and a microphone. Unfortunately the handset is currently unable to run an operating system such as Android or Windows 8 and is just a hardware prototype which is only currently capable of playing music. 

Polytron currently specialises in privacy glass – another neat item of technology which works by altering the alignment of crystals within the glass to alter the amount of light that gets though. When a current is applied to the glass it is clear and when there is no current the crystals align in such a way that lets less light though, making the glass appear cloudy. It is thought that this might be how the phone could display data.

Advanced humanoid robots

 

ASIMO (Source: Vanillase)

Walking, talking and thinking robotic pals are probably a big part of most people’s vision of the future and are a staple of science fiction’s vision of the future from HAL (crazy) to C3PO (annoying and technically from the past, somehow).  It turns out that there are several amazingly advanced robots in existence today that you might not know about.

Most people will have heard of ASIMO, first introduced by Honda in 2000. ASIMO stands for Advanced Step in Innovative MObility and the robot was designed (through 20+ years of research) to be able to walk with agility and interact with people and its environment and to improve the quality of life of humans. ASIMO can do several impressive things besides being able to run, walk, dance, climb, kick and conduct an orchestra: the 2011 model of ASIMO can work cooperatively with other ASIMO units, step aside when approached and return to its charger when it senses its batter levels are running low. 

ATLAS (Source: DARPA)

Unfortunately Honda doesn’t currently have any plans to market ASIMO. An interesting fact about ASIMO: his designers were so shocked by his lifelike movement that they travelled to Vatican City to ask whether it was cool with the man upstairs to make a robot that can walk like a person – luckily for ASIMO they gave the go ahead.

The most recent addition to the world of bipedal robots is Atlas – an adult-sized robot designed and produced by a US robotics company called Boston Dynamics contracted by the US Defence Advanced Research Projects Agency (DARPA). Atlas is perhaps less impressive than ASIMO as it is human controlled, but makes up for it with some other feats. Much like a coked-up gorilla made out of lead, Atlas is hard to knock down. It has been shown walking over rough terrain with perfect balance and balancing on one leg whilst being struck repeatedly with a large weight. Thankfully DARPA is not developing Atlas for combat applications, but to assist with search and rescue in hazardous environments.

Ion thrusters

 

It genuinely surprised me that this exists. If you remember last month’s article about interstellar travel, I talked about methods of jet propulsion to carry space crafts between stars alternative to current technologies. One such alternative method to generating thrust for space craft are ion thrusters, some examples of which already exist and have been used on the Deep Space 1 and Dawn space crafts. For some years NASA have been working on NEXT – the NASA Evolutionary Xenon Thruster – which aims to be three times more powerful than the NSTAR ion thruster used on Dawn and Deep Space 1.

The NEXT thruster: look at it shine! (Source: NASA)

In order to explain how NEXT (or any other ion thruster) functions, we have to talk about ionisation. That’s right folks – its chemistry time! (and after all, it is all about chemistry).  In their normal state, atoms exist without an overall charge – the negative charge of the electrons and the positive charge of the nucleus kind of cancel each other out (for a more detailed explanation of atomic structure, have a look at my previous article or this article at Howstuffworks.com). 

I will say first of all that I am over-simplifying this for the sake of making this article more interesting and easy to read and any sciency types going “HURURURUR  ACTUALLY, I THINK YOU WILL FIND…” will be summarily ignored. When an atom gains or loses an electron, the ‘balance’ between the negative charge of the electrons and positive charge of the nucleus is upset and the atom gains a positive or negative charge depending on what is lost or gained, becoming an ion. The reason why this happens involves the differing energy levels electrons occupy around the nucleus - I’m not going into detail because it isn’t really relevant here, but if you want to know more you can check out this excellent page on the subject.

In an ion thruster, a neutral xenon atom is released into a magnetic field along with a free electron. The atom and electron collide to produce a positive xenon ion which is accelerated through the magnetic field, propelling the craft forwards.

The NEXT thruster has recently set a record for remaining active for 5.5 years without any loss of function. The longevity and extreme fuel efficiency of this thruster gives hope for the success of more ambitious deep space missions in the future. 

Universal constructor/Cornucopia machine 

A 3D printer! (Photo by Bart Dring)

Okay, I will admit that this one is a stretch - but can't a nerd dream? You might have guessed from my previous articles (and this one) that I have no life am something of a fan of Sci-Fi. My favourite video game (and one of my favourite things too) is the 2001 masterpiece Deus Ex – and many people agree with me on this one. One of the fictional technologies featured in the game is a universal constructor, or UC. This is an example of a theorised device known as a molecular assembler – this is pretty much a machine that can construct anything by arranging atoms at the molecular level (in the case of Deus Ex this was achieved by using nanobots – nanoscopic robots).

You are probably thinking that no such thing exists – you would have heard of it. And you’d be correct.  The closest thing we have at the moment is a 3D printer. Again, I know it’s a bit of a stretch – but it is a step in the right direction. A 3D printer is an amazing device which takes a digital 3D model and constructs the object in the physical world by laying down thin layers of a material and building up a physical reconstruction of the 3D model. When you think about this for a minute, its pretty amazing – its kinda like having a magic crayon which you can draw something with and have it appear next to you (yes, I do write science articles). 

At the moment 3D printers can make things out of a wide variety of materials including metal alloys, plaster and ceramics. 3D printers are commercially available and it is possible to buy one for personal use, the cheapest ones being around £1000 (about $1600 USD) – you could buy something which you could use to make many of the simple everyday objects you might need.

Again, this is still quite far off from a machine that can make anything, but it is still amazing – and who knows? One day this technology could develop into a machine which could make literally anything and solve world hunger. So keep an eye on it.

That about rounds this one up (I know, only four items – you must feel cheated). Stay tuned for more sciencey goodness next week. In the meantime, check out the Facebook page from the link at the top of the page. 

As with every article I post here, this one has been thoroughly researched and a list of sources can be provided for anyone who is curious – just check out the contact page

Weird and wonderful - five curious critters

Breaking the streak of physics and/or space articles (but not the streak of lists of five - I'll warn you now that I might mix it up for the next one and make it a list of six and maybe make your brain explode). Without any further adieu, I bring you a list of odd organisms, curious critters, amazing animals, lovely lifeforms (I have literally thousands of these, so I'll stop now or we will be here a while).

Freezable frogs

It is hard to tell from a photograph but... this frog is not currently frozen. Photo by W-Van (Wikimedia Commons)

Many animals have very interesting methods of surviving changes in their environment – this one tops the list. The wood frog, or Rana sylvatica, is a freeze-tolerant frog which literally becomes a frogsicle in the winter months. Pretty cool, huh? (See what I did there?).

As we all know, frogs are cold-blooded. This means that, unlike warm-blooded creatures, they tend to be roughly the same temperature as their environment, so when winter rolls round the tree frogs can drop to freezing temperature. When ice starts to form on a frog’s skin, its body begins a process of putting the frog into a kind of ‘freeze mode’. If you remember my article about life in extreme environments I talked about certain bacteria producing cryoprotectants to survive in sub-zero temperatures – kind of like biological antifreeze. Probably the most abundant compound in biology which can act in this manner is glucose. The frog’s liver begins to convert stored sugars into glucose which gets pumped round the body where it protects cells from becoming damaged by the freezing process. 

This is the most fascinating part: while the frog is freezing its heart begins to slow and eventually stops completely along with all of its other internal organs. In this state up to 70% of the water in the frog’s body can be frozen and you wouldn’t be mistaken for thinking it is dead. Luckily for Kermit, this is not the case: come spring time the frog melts and happily comes back to life and resumes hopping around and doing its many and various frog things and frog-related business.

When it melts, the frog has to do some general repairs to recover any damaged cells, but other than that they seem generally unfazed by the whole ordeal. Scientists say that the frog can happily undergo numerous freeze –thaw cycles during the winter but nobody is quite sure through what mechanism their heart restarts.

Note: Don’t try this at home. It only works with a very limited number of species – I tried it with my pet frog Happy Marge and he’s gone now *sniff*.

Barreleye fish

I know it looks like some kind of novelty submarine but it is actually a see-through fish. (Source: Monterey Bay Aquarium Research Institute)

How could any list of weird and wonderful creatures be complete without some kind of freaky transparent thing?  The barreleye can be found deep down in the warmer parts of the Indian, Pacific and Atlantic oceans and has a see-through head. While this sounds a lot like something that might be witnessed whilst under the influence of the previously mentioned shrooms, I assure you it is not.

The barreleye fish is so named because of its barrel-shaped eyes which protrude from its skull into soft transparent flesh, allowing them to see. Their eyes are naturally directed upwards through their see-through head (makes sense, really), allowing them to detect prey swimming above them. 

Luckily for the freaky fish, it can also direct its eyes forward – it probably wouldn’t last long if it was constantly swimming into rocks or the mouths of big sharks or underwater sea gods and what-have-you.

  

Dumbo octopus

Have you ever seen an octopus fly? (Source)

I don’t know how scientific it is to include a creature on this list because it looks hilarious but I like to bend the rules because I’m a bit of a rebel (I have SO MANY unpaid library fines!) and I think it’s a pretty sweet octopus. Some people may be familiar with the folksy-racism-filled-fun-for-all-the-family Disney flick Dumbo. These octopuses (octopi?) are named after the eponymous elephantine hero due to the large ear-like fins growing at the top of their bodies. Yes. There actually is an octopus named after an elephant.

The Dumbo octopuses (octopi?) (Their less amusing name is Grimpoteuthis) float slightly above the sea bed using their ‘ears’ to swim, munching up any little critters they can find. They live at extreme depths of up to 7,000 meters and unlike most octopuses (octopi?) they swallow their prey whole.

There isn’t really much more to say – it’s an octopus and it has big ears. Moving on.

Armillaria bulbosa

Lovely, aren't they? Don't lick them though - you might eat your own knees and die. Photo by Dan Molter (Wikimedia Commons)

This one isn’t perhaps as interesting as the others, but someone has to stick up for the fungi. Armillaria gallica is a fungus that is thought to be amongst the largest living things in nature. In 1990 a specimen was found in a Michigan forest spanning an area of at least 15 hectares (150,000 meters squared) and weighing around 10,000 kg. It was also calculated that this particular fungus was around 1,500 years old – making it one of the largest and oldest organisms ever to be discovered.

You might be picturing a mushroom the size of a blue whale. While this would be the most awesome thing ever, it’s not quite accurate. It’s time to talk about the structure of fungi! Aren’t you lucky? The mushrooms that you eat (or smoke, lick, drink – I don’t judge) are actually not the whole fungus – they are just the fruiting bodies. Most fungi grow through the ground as long thin tendril-like cells called hyphae which grow together into a complex underground network called mycelium. The fruiting bodies, or mushrooms, are the part of the fungus which sheds spores above the ground, allowing for reproduction. Turns out they are also delicious and/or deadly and/or hallucinogenic. 

Underneath the bright yellow mushrooms (called honey mushrooms) of A. gallica lies a vast network of mycelia. Any fans of The X-Files might think this sounds familiar – the fungus was the inspiration for an episode where Mulder & Scully get kidnapped by a giant fungus and become wrapped in a vivid hallucination. For all you know you could be having a mushroom hallucination right now. I might not even exist. Or your computer. Or you… *doo dee doo dee doo doo*

Unfortunately for both of us, I do exist. I had the pleasure of working on a 9 month research project involving this magnificently massive mushroom as a microbiology student , which involved calculating how much water it contained and how much of that water a mouse might absorb… I know, right? It was a rollercoaster. You can imagine how glad I am to be able to talk about these things once more. 

To counterbalance the boringness of this section I will give you an interesting fact: Beatrix Potter, the author of children’s classics such as Peter Rabbit, was as mushroom expert.

Sea Sparkle

Purty, ain't it? (Source)

This is literally one of my most favourite things in the universe. I am aware that this sounds like a character from a weird, brightly coloured and annoying Japanese children’s cartoon, but I assure you it isn’t. Sea sparkle is the friendly name for a single-celled-organism called Noctiluca scintillans – I know, catchy. During the day sea sparkle isn’t much to look at; in fact it can be responsible for huge, ugly red blooms on the surface of the sea called ‘red tides’. At night time though, it’s a whole different story. You guessed it - it sparkles!

When something living glows, biologists give it the fancy name bioluminescence. In many cases bioluminescence is caused by a luciferin-luciferase reaction. This is the same process which makes fireflies glow and involves a chemical called luciferin interacting with an enzyme called luciferase in the presence of oxygen. Enzymes are proteins which lend a helping hand to biological chemical reactions, and in this case luciferase converts oxygen and luciferin in to a molecule called oxyluciferin which emits light.

When sea sparkle is in still water it doesn’t glow because it isn’t in contact with oxygen – this missing ingredient prevents the bioluminescence from happening all the time. When the water is disturbed, by a wave or a swimmer for example, the cells come into contact with the air and the reaction begins, producing a beautiful otherworldly blue glow.

Scientists believe that this light show is a defence mechanism taking advantage of the food chain. If a small fish comes along and begins to feed on the poor sea sparkle cells it will disturb the water, inevitably causing the awesome blue glow. This blue glow will then attract a bigger fish which will come along and much down the smaller fish,  leaving the sea sparkle to glow another day. I guess in this situation everyone wins… except the little fish. There is probably a profound life lesson in this – there is always a bigger fish.

If you ever happen to be visiting Puerto Rico, I highly recommend checking out a bioluminescent bay.

Also, please check out an article by a fellow blogger Peter Harrison:
http://endlessforms.net/2013/01/22/my-top-5-weirdest-animals/

That about does it for me, join me next time for something possibly technology related (exciting!). In the meantime, check out the Facebook page from the link at the top of the page.

As with every article I post here, this one has been thoroughly researched and a list of sources can be provided for anyone who is curious – just check out the contact page.