Zombie Birds, Astronaut Fish, and Other Weird Animals

by Becky Crew

  “Marvelous beasts, aren’t they?” I remarked, gesturing at the rug with my glass of rye.

  “You have no idea,” said the man, addressing his untouched glass of deep red wine in a dreary, yet unmistakably ominous, tone.

  “You’ve seen one?”

  “I’ve seen everything,” he told me, exasperated, pained, and intensely bored all at once.

  “That explains why you’re not scared of spiders!”

  The man gave his wine glass a withering look.

  I offered one of my free legs to him. “My name is Pavenic. I’m an art dealer on my way to Mooreth.”

  “I know who you are. And I know that you’re no ordinary spider.” He was ignoring my outstretched leg.

  “You do?”

  “My name is Farkaskoltus, I am a vampire, and I am 4000 years old. I think you should take a seat.”

  That night I stood in the bathroom doorway of my hotel room, willing myself to go in. “Just go in, regard yourself in the mirror, and put an end to all this nonsense. You’re not a vampire, you’re just a normal spider.” But I knew it was fruitless. I wasn’t a normal spider. I’ve never been a normal spider, because of the blood.

  The next morning I postponed my trip and retreated home. At my request, Grul strung black, floor-length curtains across every window, never to be drawn. It was a miracle, said Farkaskoltus, that I’d survived the sunlight for so long. I isolated myself from the rest of the village, because that seemed like the appropriate thing to do.

  “Sir, the mayor has left something for you. A gift, in return for the generous donation you made to the hospital after their entire blood supply went missing …”

  “I know you’re trying to make me feel guilty, Grul, but it won’t work. Let me see that.”

  The gift was wrapped in an ornately embroidered handkerchief made of cotton the color of antique ivory with brilliant maroon lace around its edges. I gently peeled away the edges to reveal a silver eggcup with a delicate golden rim. It was so highly polished, I could actually see myself in it. “Good God!” The eggcup tumbled to the floor and rolled smoothly under a nearby armchair. “Is that what I look like now? Wait, why do I have a reflection? What the devil’s going on here? Could Farkaskoltus have been a simple con artist?”

  “That would explain why he insists you send your monthly Vampire League membership fee directly to him, sir.”

  “So I’m not really a vampire spider after all. I’m just a normal spider. I’m just a normal spider.” It had well and truly dawned on me. I was just a normal spider. “Grul, I’m melancholy.”

  “If it’s any consolation, sir, you’ll always be a vampire as far as the villagers are concerned.”

  “That’s true, Grul. Good point.”

  So Grul and I strapped a drained and headless corpse to one of my dappled mares and sent it down the hill to the village square. It seemed like the appropriate thing to do.

  A Slime-Wielding Predator

  HAGFISH

  (Myxine glutinosa)

  Dear Manager

  I am writing in response to your accusation that I left your establishment on Saturday night without paying for my meal. If I had eaten my meal, I would have paid you for it, but as several witnesses will tell you, I never once opened my mouthparts. If I knew how my meal disappeared like that, I would tell you. But I don’t.

  Please find enclosed your unpaid bill, which I trust you will refrain from sending me in the future.

  Yours sincerely

  Hagfish

  CLEAR CONTENDER FOR UGLIEST creature in the world, the hagfish is one of the only surviving jawless vertebrates in the world, unchanged since its ancestors slunk around the ocean between 530 and 300 million years ago. Long thought to be sedate scavengers, researchers have recently unmasked these primitive, eyeless “snot eels” as skilled, slime-wielding hunters.

  Though technically classified as a vertebrate (an animal with a backbone), the hagfish is so primitive that its backbone is nothing more than a flexible rod of tissue cells called a notochord. Hagfish are found all over the world, at depths of between 165 and 2300 feet below sea level, trawling the bottom of the ocean for carrion and other decaying food scraps. If a hagfish is lucky enough to come across a sizeable carcass it will ensconce itself inside, and rather than nibble at it with its mouthparts, it will absorb the nutrients directly through its skin.

  In early 2011, researchers led by physiologist Chris Glover from the School of Biological Sciences at the University of Canterbury in New Zealand discovered this phenomenon by watching what happened when two types of radioactively labeled amino acids were applied to multiple pieces of hagfish skin and gills. Publishing in Proceedings of the Royal Society B, the team described how the amino acids passed easily through the outer layers of the skin and gills, which is often seen in invertebrates (animals without backbones) such as jellyfish, corals, and sea stars, but never in another vertebrate. This is because vertebrates need to regulate their internal environment, which is why we humans have such impermeable skin. But somehow the hagfish has evolved in such a way that it can cope with serious changes to its internal chemistry.

  The researchers suggested that this could be because the hagfish represents a transitional state between the simple feeding mechanisms of aquatic invertebrates and the more specialized and complex digestive systems of aquatic vertebrates. So by absorbing its food through its skin, the hagfish could be demonstrating how it is a combination of vertebrate and invertebrate characteristics, its bizarre eating behavior a reminder of how little it has changed in millions upon millions of years.

  Although they weigh only 5 ounces, hagfish can each produce over 5 gallons of slime in a matter of minutes. They are covered in a collection of slime glands that are connected to two rows of 90–200 pores that run down the full length of their bodies. When threatened, the hagfish will excrete huge amounts of mucins, which are slimy, gel-like secretions bonded together with protein threads that expand the instant they come in contact with seawater. To avoid being smothered by its own cloud of goo, the hagfish will twist its body into an overhand knot and slide through itself, wiping itself clean as it escapes.

  Researchers have long assumed that the purpose of the hagfish’s ability to produce such copious amounts of slime was to defend itself against gilled predators, because some captive hagfish had been accidentally blocking their own gills with it and suffocating. Using underwater cameras set up off the coast of Great Barrier Island in New Zealand, a team of researchers, led again by Glover, obtained video footage of this occurring in the wild for the first time. They reported in a mid-2011 issue of Nature that the “slime secreted by hagfishes fills the mouth and gill chamber of their predators, acting as a very rapid (<0.4 sec[ond]) and effective defense mechanism. The predators convulsed their gill arches dramatically in a gagging-type effort to clear the slime from their gill chambers.”

  The video footage showed an array of species being overwhelmed by hagfish slime, including sharks and bony fishes. Each time, the hagfish would remain where it was, unharmed, while the predator moved away, gagging. Because they can only refer to what they can see in the video footage, the researchers are not sure whether these predators eventually died due to suffocation from the slime, or survived because the slime dissolved in the water soon after.

  What the researchers didn’t expect to see in their video footage was hagfish actively hunting their prey. One species—the slender hagfish (Nemamyxine elongata Richardson)—actually chased a red bandfish into its seafloor burrow and grabbed it with its twin rows of teeth, called toothplates. When the hagfish emerged from the burrow the bandfish was incapacitated, and the researchers suggested that it could well have been slimed. Not bad for one of the most primitive marine vertebrates on Earth.

  The Spider-Eating Spider

  PALPIMANUS SPIDER

  (Palpimanus gibbulus and Palpimanus orientalis)

  “What’ll it be, sir? Are you interested in any of our specials this evening?�
�

  “I think I’ll just have the spider, thanks.”

  “No, I said ‘what’ll it be’.”

  “I know. I said I want the spider.”

  “But sir, you’re a spider …”

  “Do you mind keeping it dow—never mind, everyone’s looking now. It’s cool, everyone, I’m not a cannibal, I’m just getting a beer.”

  “A beer? You didn’t order a beer. But if you want a beer, I can get you a beer—”

  “Just give me a Whale Ale.”

  “—to wash down that cannibal meal you just ordered. Sicko.”

  THEY’RE THE SPIDERS OTHER spiders should be terrified of. Not only are the species Palpimanus gibbulus and Palpimanus orientalis built to battle spiders up to twice their size, but their stealthy patience and ninja-fast moves are the perfect combination for turning the hunter into the hunted.

  These two species belong to the Palpimanus family, which includes about 100 species of elusive spiders that all have huge, strong forelegs, which are kept raised while the spider is walking. P. orientalis and P. gibbulus are the only spider-eating Palpimanus spiders, and they are found in Mediterranean countries such as Portugal, Spain, and Israel. Told apart only by the shape of their sex organs, this fearsome duo sport bright red, heavily armored abdomens and rich, brown cephalothoraxes, the area that combines the head and the thorax. Both species are extremely rare and nocturnal, so it wasn’t until February 2011 that researchers from the Czech Republic discovered exactly how they executed their hunt. “Ten years ago, I went to Israel to the Negev desert … and I came across a number of these peculiar spiders. With their huge forelegs they looked like wrestlers,” says lead researcher Stano Pekár, an assistant professor from the Institute of Botany and Zoology at Masaryk University. “A colleague told me that these are supposed to feed on other spiders. So I performed first feeding trials and [then] observed their behavior, which was very strange. I found that they refuse most other prey but spiders.”

  Catching over 150 individuals, the researchers dropped them in a box with another spider species and watched what happened through the lens of a high-speed camera. Once a Palpimanus spider recognized its prey, it moved very slowly toward it, forelegs raised. When it was about half a body length away it stopped dead still, legs up, ready to strike. The moment the prey decided to move, the Palpimanus spider would lunge at it, grabbing at its body with its forelegs and biting it with its fanglike chelicerae. It would manage all of this in the space of 0.2 seconds. Once the prey was overcome, the Palpimanus spider would wrap it up in silk and start feeding on it. In 90 percent of Pekár’s trials, the two species of Palpimanus spiders managed to successfully overcome their prey, and in the other 10 percent of trials they were captured by rival spiders.

  The researchers had a close look at the Palpimanus spiders’ legs under an electron microscope, discovering that every inch of these species works to ensure they are the perfect predators. Each leg ends with a dense pad of 1500 hairs, called scopulae, which allow the spiders to grip their prey using the same force that allows all species of spiders to climb walls. When Pekár covered the pads in paraffin wax, the spiders’ success rate fell so drastically that instead of needing an average of 1.4 tries to catch a meal, they needed 5.9.

  In the wild, these spider-eating spiders don’t have the benefit of an enclosed space alone with their prey, which can often successfully outrun them. For this reason, the researchers think the Palpimanus spiders target so-called retreat-dwelling spiders that hole themselves up in burrows and silk cocoons. If the only exit is suddenly blocked by a Palpimanus spider, there’s not much a retreat-dwelling spider can do to get away, except inflict a lethal bite. Which won’t do them much good either, because both P. orientalis and P. gibbulus are protected by a layer of cuticle that is twice as thick as the cuticle worn by other spiders on their front halves, and five times as thick on their back halves.

  But despite their tough exterior, these Palpimanus spiders aren’t particularly aggressive. “These spiders are indeed very calm,” says Pekár. “For most of the day they sit motionless under rock and come out only at night. When they come across a web or a retreat, they invade it and aim to catch the spider. If the spider escapes, they wait patiently … for its return.”

  These are not the only known spider-eating spiders. Portia is a genus of spider-eating jumping spider that includes seventeen species found in tropical forests everywhere from Africa, Australia, China, Malaysia, Nepal, and the Philippines. Portia spiders don’t have thick armor, massive forelegs, and hairy pads, so they rely far more on strategy than sheer brawn. They wait until their prey is distracted by food before attacking, or using cryptic stalking to disguise their approach, twanging the silk of a prey’s web to imitate struggling prey or the courtship signals of a mate.

  Portia spiders have proven themselves to be intelligent hunters in laboratory experiments, performing unusually well in a number of problem-solving tasks. White-mustached Portia spiders (Portia labiata) have been named one of the smartest animals in the world for their uncanny ability to learn from previous experience, remembering the rhythmic patterns that work to capture the spider species that they have encountered before. They are also incredibly patient planners, sitting and waiting for hours if they miss their prey, knowing that it will return to a particular spot.

  A Mind-Controlling Parasite

  GREEN-BANDED BROODSAC

  (Leucochloridium paradoxum)

  “Hey man, let’s go shopping, you’re low on Doritos.”

  “I just bought you an entire packet yesterday! Fine, okay, but can you please tell me when you plan on moving out of my stalks? I get that this is nature and sometimes some of us have to deal with having parasites, but, I don’t know. I feel like I’m going crazy or something, like you’re doing something to my brai—Hey, there’s a bird, let’s go say hi.”

  YOU’D BE HARD-PRESSED TO find an organism more despicable than the helminth. These wormlike creatures, also known as flatworms, are defined by their ability to live inside and feed off living hosts, stripping them of their nutrients and wreaking havoc on their digestive systems. While we humans (and our pets) have to worry about helminths such as roundworms, hookworms, and whipworms, which make homes in our intestines through contaminated water or soil, snails and birds face the terrifying prospect of an encounter with the green-banded broodsac.

  First discovered in Germany, the green-banded broodsac maintains an incredible lifestyle. As with all life cycles, it can be pretty difficult to decide where to start, but when you’re talking about flatworms, a pile of shit seems pretty apt. Ranging from northern to central Europe, the green-banded broodsac lays its eggs in bird feces, which a species of small, amber-colored snail called Succinea putris promptly eats. Luckily for the green-banded broodsac, the snail cannot digest these eggs, so once in the snail’s digestive system, the broodsacs hatch into free-swimming larvae called miracidia.

  Not content to spend its days inside a lowly snail, the green-banded broodsac sets its sights on a grander home—a mansion with wings. While inside the snail’s stomach, the larvae use their tiny, fiberlike structures called cilia to move from the snail’s stomach to its eyestalks. Here the larvae will morph into a more advanced form of larvae and then team up in hundreds to create long, living tubes called sporocytes. The sporocytes not only give the snail’s eyestalks a colorful appearance, but they also hinder the snail’s eyesight and override its preference for dark environments in order to make it more visible to the green-banded broodsac’s original host.

  Once the parasitized snail stumbles out of the darkness, unable to see that it is now in danger of being spotted by predators, the light causes the sporocytes to twitch and pulsate, giving the eyestalks the appearance of two juicy caterpillars. A passing bird will spot the infected stalks and tear them from the snail’s head, ingesting the broodsac larvae in the process. At this stage the larvae will transform once again, this time into adult flatworms, while the snail is left
to die or be reinfected. The adult flatworms will breed at a rapid rate inside the bird’s digestive system, producing hundreds of eggs that will end up in the bird’s droppings. And so the sickening life cycle of the green-banded broodsac is complete.

  I hope you weren’t eating just now.

  Isopod Got Your Tongue?

  TONGUE-EATING ISOPOD

  (Cymothoa exigua)

  IN 1983, A NEW species was discovered that is literally your worst nightmare if you’re a fish. Known as the tongue-eating isopod, this parasitic crustacean belongs to a group including woodlice and pill bugs, whose ancestors date to at least 300 million years ago. There are over 4000 species of isopods living in the world’s oceans, and they make a living out of parasitizing other animals, but none go to the extreme lengths of the tongue-eating isopod to ensure a lifetime of easy meals.

  In 2009, a tongue-eating isopod was discovered inside a type of large fish called a weever by fishermen off the Minquiers, near the Island of Jersey in the English Channel. This 0.8-inch-long buglike parasite had burrowed into the fish through its gills, attached itself to the muscular base of the tongue and sucked the blood from it until it withered away to nothing. Grasping the inside of the fish’s mouth, the isopod plays the part of a replacement tongue, feeding off the scraps of food that enter its mouth. This is the only known case of a parasitic animal being able to replace a host organ so effectively.