Scientists have documented the largest spider web ever found, a colossal structure spanning over 100 square meters within a cave on the Albania-Greece border, home to more than 111,000 common spiders exhibiting an unprecedented form of colonial living.
The massive web, covering 106 square meters, is situated in the permanently dark zone of a cave system. It adheres to the walls of a narrow, low-ceilinged passage near the entrance.
The vast arachnid community consists of two species commonly found near human settlements: Tegenaria domestica, known as the barn or house spider, and Prinerigone vagans. Researchers estimate approximately 69,000 T. domestica and over 42,000 P. vagans inhabit the web.
This discovery marks the first evidence of such extensive colonial behavior in these common spider species. Dr. István Urák, Associate Professor of Biology and lead researcher, described the phenomenon as "a unique case" and one of the largest colonies ever recorded.
Details of the find were published on October 17 in the scientific journal Subterranean Biology.
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The spiders reside in a unique geological formation known as the "Cave of Sulphur." This cavity was formed by sulfuric acid resulting from the oxidation of hydrogen sulfide in groundwater.
While Czech cavers first observed the giant web in 2022, a 2024 expedition provided DNA analysis and samples. These confirmed the specific species and scale of the colonial structure.
Dr. Urák expressed profound "admiration, respect, and gratitude" upon witnessing the sprawling web. He noted that its full impact must be experienced firsthand.
The research team emphasizes the importance of preserving this unique colony. Dr. Urák acknowledged potential challenges given the cave’s location straddling two countries.
Further studies are underway to uncover additional details about the inhabitants and the dynamics of the "Cave of Sulphur" ecosystem.