A fungus that infects cave spiders, controlling their behavior and turning them into “zombies” has been discovered in Northern Ireland during the filming of a documentary series.
The fluffy white fungus, similar to the well-known cordyceps fungus that infects ants, probably also uses chemical signals to direct infected cave spiders from their lairs to the open air.
According to the new study, the fungus kills spiders and uses their corpses to release its spores.
The fungus was first discovered in 2021 by participants of the BBC nature documentary series Winterwatch in an abandoned Victorian powder magazine on the territory of the Castle Espie reserve.
Scientists analyzed the fungus and found that it is new to science. This species, named Gibellula attenboroughii in honor of Sir David Attenborough, was described in a study published on January 24 in the journal Fungal Systematics and Evolution.
Where it was found
The fungus was found on a dead cave spider, Metellina merianae (a family of spiders that includes our cross spider). Spiders of this species usually live in caves, but they also live in dark places created by humans, such as basements and old barns.
According to the study, after an accidental discovery in 2021, study co-author Tim Fogg, a caving specialist, found even more specimens of the fungus in cave systems in Northern Ireland and the Republic of Ireland, including another species of cave spider, Meta menardi.
Usually, cave spiders hide in lairs or webs, but all the infected individuals were on the roofs and walls of the caves, and the first spider found in the powder magazine was on its ceiling.
The researchers assumed that the fungus changed the behavior of the spiders, sending them to open areas where air currents disperse its spores.
The process of spider infection
Lead author of the study, Harry Evans, said that the process of infection with the fungus is complex, and G. attenboroughii could have evolved with cave spiders.
Evans explained that G. attenboroughii spores penetrate the spider and infect its hemocoel, a cavity that contains the equivalent of blood in invertebrates. After the spider leaves its lair, G. attenboroughii produces a toxin to kill its host and then uses antibiotics – antimicrobial substances that kill bacteria – to preserve the corpse and mummify it. The fungus absorbs all of the spider’s nutrients, and under favorable conditions, such as high humidity in a cave, G. attenboroughii grows long structures on the spider to disperse its spores.
While the connection between the fungus and spiders is interesting, Evans noted that the end point of this research will potentially be medicines that can be derived from the substances the fungus produces.
“This is a treasure chest of medicinal treasures,” he said.
The kingdom of fungi
Evans and his colleagues extracted DNA from the fungus to confirm that it was a previously unknown species. So far, it has only been found in Ireland, but the researchers also suspect that G. attenboroughii infects cave spiders in Wales, based on photographs of the same fungus.
The study emphasized that there is a hidden diversity of parasitic fungi in the British Isles and that many more species are likely to be discovered.
“There are many more fungi to be found,” Evans said. – “The fungal kingdom may consist of 10, 20 million species, making it the largest kingdom by far, but only 1% have been described.
G. attenboroughii was originally supposed to be called G. bangbangus – “bangbangus” refers to the gunpowder warehouse where the fungus was found. However, the authors of the study changed the name of the species in honor of Attenborough.
