A creepy video that's gotten new life as a GIF shows a slime mold on the hunt.
The slime mold, a species called Physarum polycephalum, is not actually a mold at all; it's a single-celled protist. These giant cells can grow to square meters in area, though most are a few square centimeters or inches instead. Their potential for enormous size explains the movement and flowing "veins" seen in the mesmerizing video and GIF, said Audrey Dussutour, a researcher at Universite Paul Sabatier in France who studies slime molds.
"What it's doing is compressing and contracting these veins, and by contracting these veins, the liquid is pushed forward against the membrane" of the cell, Dussutour told Live Science. This liquid movement of the cell's cytoplasm pushes the cell forward, she said. The cytoplasm veins also carry nutrients throughout the organism. [Tiny Grandeur: Stunning Photos of the Very Small]
Unlike most cells, those of P. polycephalum have many nuclei, meaning they make decisions "by committee," said Megan Dobro, a biologist at Hampshire College in Massachusetts. This makes slime molds intriguing objects of study for scientists, who have found that the organisms can store "memories" of past events in their slimy trails, despite being entirely brainless. Chemical information stored in the slime trails can help lead a slime mold to a food source faster, one study found, because the mold doesn't waste time sending out feelers into areas it's already explored.
Slime molds can even learn, Dussutour and her colleagues have found, and then pass on that learned information by fusing with other slime molds.
And they just look cool, especially for something gooey that prefers to lurk on the underside of moist leaves. In one study, researchers set out dabs of oatmeal (a favorite food for slime molds in the laboratory, Dussutour said) mimicking the location of cities around Japan. Slime mold let loose on this playground of food formed a network that beautifully mimicked Japan's rail system.
The GIF recently getting attention on Reddit is a sped-up version of an already sped-up video originally posted on YouTube in 2011. User Will Stevens made an 8-minute time-lapse video of the slime mold growing over the course of two days, sending tendrils out to four different circles of food. The slime mold advances and retreats in response to what it finds as it explores.
"It's optimizing the shape of its network as it takes in information," Dobro told Live Science.
It's hard to describe the slime mold's behavior precisely without knowing more about what was in the food, Dussutour said. (Live Science was unable to reach Stevens by press time.) In the wild, slime molds eat fungi and bacteria, she said. In lab dishes, the slimy cells can detect oats from about 0.4 inches (1 centimeter) away, she said, and sugar from an inch (2 to 3 cm) away. When the molds run low on food and moisture, they can enter a dormant state for up to a year.
There are multiple species of slime mold, Dussutour said, but even among the same species, different strains seem to have different personalities. In her lab, one strain bought from a United States supplier is constantly escaping its dish, she said, while her Australian strain is "really quiet."
"You get attached to them," she said.
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Originally published on Live Science.
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Stephanie Pappas is a contributing writer for Live Science, covering topics ranging from geoscience to archaeology to the human brain and behavior. She was previously a senior writer for Live Science but is now a freelancer based in Denver, Colorado, and regularly contributes to Scientific American and The Monitor, the monthly magazine of the American Psychological Association. Stephanie received a bachelor's degree in psychology from the University of South Carolina and a graduate certificate in science communication from the University of California, Santa Cruz.