Several scientists in Europe discovered a previously unknown species of fungus that turns cave spiders into "walking zombies." The fungus lures them out of their webs before instigating an untimely death and then uses the spiders’ corpses to spread its spores.
Read More......
The newly discovered species, named Gibellula attenboroughii, acts in a similar way as the zombie ant fungus, seemingly manipulating its prey to move to a more suitable spot for the fungus to spread, according to a study published 24 January in the journal Fungal Systematics and Evolution.
But the way in which the fungus affects the arachnid’s brain is still a mystery, and a multitude of questions remain about the fungus’ evolutionary pathway and ecological impacts.
"We know very well the ants, the wasps, and very few other examples. And now this is in a different family, so it’s a new origin of behavior manipulation," said study coauthor Dr. João Araújo, a mycologist at the Natural History Museum of Denmark and an assistant professor at the University of Copenhagen. "It’s something really interesting that’s not super common in the parasitic world."
The finding opens up new research opportunities to better understand animal-controlling fungus and illuminates the diversity of fungi yet to be uncovered, researchers said.
The newfound species is part of a larger branch of fungi that exclusively infects spiders.
Researchers observed a different species of Gibellula (G. aurea found in Brazil) possibly manipulating spiders to move to the underside of leaves before death, as described in a November 2022 study coauthored by Araújo. However, the maneuver was not as strikingly evident as it is when G. attenboroughii targets cave spiders, Araújo said.
So far, scientists have only observed G. attenboroughii infecting the spiders Metellina merianae and Meta menardi, both cave-dwelling orb weavers that are found in Europe.
The first sighting of the peculiar fungus has a colorful backstory: In 2021, a television crew first spotted the fungus on an orb weaver spider while filming a show in an abandoned gunpowder storeroom at Castle Espie Wetland Centre in Northern Ireland’s County Down.
The crew noticed that the spider placed itself in an exposed position before death, away from its web, suggesting the fungus had caused behavioral change.
Further observations revealed more infected spiders in caves in both Northern Ireland and Ireland, all positioned in exposed areas of the roof or walls of the chambers, according to the study.
"Most spiders that are web-building spiders very much like to stay on their web. They’re built to be good inside of a web, but then they’re actually quite bad at walking around on the ground," said Dr. Jay Stafstrom, an expert on arachnid sensory ecology and postdoctoral researcher at Cornell University in Ithaca, New York.
"The fact that a fungus can infect something and then behaviorally alter that animal so that it then helps the fungus spread, I think it’s just very intriguing," said Stafstrom, who was not part of the study.
The researchers said they are unsure of the exact mechanics and inner workings of the fungus. But the team hypothesizes the fungus lures the spiders out of their lairs where they are exposed to circulating air currents, which helps spread its spores, said Araújo, who is also an honorary research associate at the Royal Botanic Gardens, Kew, in the United Kingdom.
Posts
