#arthrobotrys

“Maybe it's just us, but it's somewhat unsettling to realize that this insidiousness is all the work of a fungus, a thing that can seem so inert compared to the wiggling, active worm that it targets. But fungi do have a kinship with horror stories. Their frequent roles as decomposers naturally connects them with the dead. Plus, they come equipped with their own creeping sense of dread with images of mycelia weaving through bodies.”

Journey to the Microcosmos- The Fungus That Traps and Kills Nematodes

Images Originally Captured by Jam’s Germs

“But whatever we seek to scare ourselves with in fiction, horror has its purpose in nature. As we've pointed out, nematodes are one of the most abundant animals on earth. They play an important role in decomposition...but they're also the source of many diseases--both in animal bodies and in plants. So having them slightly less abundant is important to our ecosystem as well... So as is the case with many good horror villains, there is a version of this story where the nematode-trapping fungus is the hero. Unless, of course, you're the nematode.”

Journey to the Microcosmos- The Fungus That Traps and Kills Nematodes

Images Originally Captured by Jam’s Germs

“Here is one nematode, just reacently trapped. And here is the worm again, four days later. You can see the infection bulb where the fungus first punctured and expanded. And the whole body of the worm seems taken over, no longer a clear tube, but instead a corpse that has become home to its cause of death.”

Journey to the Microcosmos- The Fungus That Traps and Kills Nematodes

Images Originally Captured by Jam’s Germs

“The fungus hyphae begin to grow off from the loop, puncturing the worm's cuticle and paralyzing it. The threads swell up into a bulb that produces more hyphae to spread through the rest of the nematode. And then the fungus feeds and feeds, quickly digesting the rest of the nematode's body from within. It is a gruesome death.“

Journey to the Microcosmos- The Fungus That Traps and Kills Nematodes

Images Originally Captured by Jam’s Germs

“It begins by weaving a trap out of itself. It threads the hyphae of its mycelium out and then back in, forming a living loop that repeats to form a net. But a net is only one part of a trap--the other part is the lure. The fungi can find nematodes by following traces of their pheromones like they're breadcrumbs. And more nefariously, they can mimic the smell of certain food cues to draw the worm in, like a siren working through scent instead of song. The nematode has no reason to suspect anything, even as it swims closer and closer and eventually through the fungal rings. But as it does, the movement of worm and water triggers the rings to constrict. The worm is trapped, but the worst is still yet to come.”

Journey to the Microcosmos- The Fungus That Traps and Kills Nematodes

“It does spend much of its life aligned with the dead, but only to sustain itself on the remains of decayed life and organic matter. Arthrobotrys species are found all around the world, occupying everything from soil to animal feces in the many varied climates that make up our planet. And wherever it is, the fungus ensures that nutrients like nitrogen from dead organisms and other waste cycle through ecosystems. But when nitrogent is carece, these fungi will resort to hunting in down from living sources. And what better prey than the nematode, a fellow dweller of the soil and one of the most abundant animals on earth?”

Journey to the Microcosmos- The Fungus That Traps and Kills Nematodes

“When James put his slides into the humidity chamber, he had no notion of what these nematodes would be facing, and so no expectation of what he would find. But when the slides came back out, what he observed was something he'd only seen once before, in a drawing done two years ago by one of his close friends, Katelyn Solbakk. In it, you can see a nematode whose body has been clinched into segments by some kind of bulbous... thing. What you're seeing is the fungus' most brutal design. But to get there, it must morph from decomposer to predator--no longer consuming what has already been dead, but actively killing..”

Journey to the Microcosmos- The Fungus That Traps and Kills Nematodes

Images Originally Captured by Jam’s Germs

“We're looking at the spores of a fungus, one belonging to the group Arthrobotrys. And when it's just floating around like this, it seems quite harmless--especially when compared to the nematodes we showed earlier, which are part of a whole family of worms that are notorious for their parasitic lifestyle. And if you were to write off Arthrobotrys as a potential threat, you would be correct... most of the time.”

Journey to the Microcosmos- The Fungus That Traps and Kills Nematodes

Images were Originally Captured by Jam’s Germs