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Yahoo
2 days ago
- Science
- Yahoo
Watch 'superorganism' created by tiny worms — the first time it's ever been spotted in the wild
When you buy through links on our articles, Future and its syndication partners may earn a commission. Nematodes have been spotted forming writhing towers of tiny worms in the wild for the first time, according to a report in the journal Current Biology. The bizarre behavior had previously only been observed in experimental settings, thought to be a competitive attempt to escape from the rest of the group. However, new images of these towers forming in the wild hint at a more mutually-beneficial motivation. The footage was captured by researchers in Konstanz, Germany, on fallen apples and pears at local orchards. The team from the Max Planck Institute of Animal Behavior (MPI-AB) and the University of Konstanz were then able to combine these images with follow-up laboratory experiments to demonstrate that the 'towering' behavior happens naturally, and that the worms engage in such behaviour as a means of mass transit. 'I was ecstatic when I saw these natural towers for the first time,' said senior author Serena Ding, group leader at the MPI-AB, describing the moment when co-author Ryan Greenway, a biologist at the University of Konstanz, sent her a video recording from the field. 'For so long natural worm towers existed only in our imaginations. But with the right equipment and lots of curiosity, we found them hiding in plain sight.' That curiosity also revealed some interesting aspects of worm cooperation. While the researchers observed many nematode species crawling inside the fruit, only a single species in the same developmental period — a tough larval stage known as a 'dauer' — participated in tower building. That level of species specificity in worm tower 'construction' hinted that there might be more driving the behavior than a seemingly random creature cluster. Related: Nematode resurrected from Siberian permafrost lay dormant for 46,000 years 'A nematode tower is not just a pile of worms,' said study first author Daniela Perez, a postdoctoral researcher at MPI-AB. 'It's a coordinated structure, a superorganism in motion.' The paper suggested these observations could serve as a 'missing link' into behavior of similar organisms. Such towering behavior has previously been observed in slime molds, fire ants and spider mites, but it is still relatively rare in nature. To see if other kinds of worms could also form such a 'superorganism', researchers created conditions to coach the roundworm Caenorhabditis elegans into assembling into similar structures. C. elegans is a model organism that is widely studied for both its behavior and biology. Perez stuck a toothbrush bristle into a food-free agar plate to act as a sort scaffold — then unleashed the worms. Within two hours, the C. elegans formed a tower using the bristle as its spine. Some smaller clusters of worms reached out exploratory 'arms,' while others bridged gaps between spaces. And when researchers tapped the top of the tower with a glass pick, the worms wriggled toward that stimulus. 'The towers are actively sensing and growing,' says Perez. 'When we touched them, they responded immediately, growing toward the stimulus and attaching to it.' RELATED STORIES —Why do worms come out in the rain? —Australian 'trash parrots' have now developed a local 'drinking tradition' —Wandering salamander: The tree‑climbing amphibian with a blood‑powered grip The researchers also wondered if there was some sort of worm hierarchy driving this activity. Did younger worms have to do all the work? Stronger ones? Smaller, weaker ones? It turns out that the roundworms were remarkably egalitarian in their efforts. Unlike the orchard-based nematodes, the laboratory-bound C. elegans represented a range of life stages, from larval to adult — but they all pitched in. That suggests 'towering' may be a more generalized strategy for group movement than previously thought. 'Our study opens up a whole new system for exploring how and why animals move together,' says Ding.
The Independent
19-02-2025
- Science
- The Independent
Scientists perplexed to see wild fish recognise specific humans: ‘It was like they were studying us'
Scientists at a Mediterranean research station have found that some wild fish can tell apart humans, recognising and targeting specific divers who had fed them before. The study, published in the journal Biology Letters on Tuesday, found that some wild fish can use visual cues to identify specific humans even when their faces are covered by diving gear. Previous lab studies have shown that captive fish, like archerfish, can recognise human faces in controlled settings. However, there is little evidence that wild fish could do the same, say researchers from Germany 's Max Planck Institute of Animal Behaviour (MPI-AB). To test this, scientists conducted a series of experiments at a research site eight meters underwater in the Mediterranean Sea where wild fish have become habituated to divers. In the first phase of the experiments, study co-author Katinka Soller attempted to attract the attention of local fish by wearing a bright red vest, and fed fish while swimming a length of 50m. Gradually, she removed the vest and wore plain dive gear, kept the food hidden, and fed fish only after they had followed her the full 50m. The fish, according to scientists, were 'willing volunteers' in the study who came and went as they pleased. Two species of seabream fish were particularly willing to engage, they said. After 12 days of training, 20 fish followed Ms Soller, who could recognise several of the fish from their physical traits. 'There was Bernie with two shiny silver scales on the back and Alfie who had a nip out of the tail fin,' she said. In the next experimental phase, researchers tested if these same fish could tell Soller apart from another diver, study senior author Maëlan Tomasek. Dr Tomasek's diving gear 'differed notably' in some colourful parts of the wetsuit and fins, researchers said. This time the divers started at the same point and then swam in different directions, but Dr Tomasek never fed the fish that followed him. Scientists were surprised to find that while the fish followed both divers equally on the first day, the number of fish following Ms Soller increased significantly from day two. Researchers then focused on six fish out of the large group to study individually and found that they showed 'strong positive learning curves.' The findings suggest the fish were conscious of both divers and tested each one to learn that Katinka produced the reward at the end of the swim. However, when scientists repeated the experiment wearing identical diving gear, the fish were unable to discriminate them, they say. Based on this observation, researchers suspect the fish associated differences in the dive gear – most likely the colour cues – with each diver. 'Almost all fish have colour vision, so it is not surprising that the sea bream learned to associate the correct diver based on patches of colour on the body,' Dr Tomasek said. 'We already observed them approaching our faces and scrutinising our bodies. It was like they were studying us, not the other way around,' Ms Soller said.
