Scientists have identified what may be the world’s largest spider web inside an underwater cave located along the Greece–Albania border.
According to a recent report in the international science journal Subterranean Biology, the web covers an extraordinary 1,076.4 square feet along the wall of Sulfur Cave and supports an estimated 110,000 spiders from two species. Researchers recorded approximately 69,000 Tegenaria domestica spiders and 42,000 Prinerigone vagan spiders, marking the first documented case of colonial web-building for either species.
“Molecular data confirmed the identity of the two spider species and revealed that their populations in Sulfur Cave are genetically distinct from other populations,” the journal noted. “Regarding T. domestica, we found a seasonal pattern in fecundity, with significantly larger egg clutches in early summer.”
The cave’s unique environment appears to sustain the vast colony thanks to abundant resources. Scientists also identified 512 additional species from 20 different families living within the cave ecosystem.
A team from the Czech Speleological Society first encountered the massive web in 2022. Researcher István Urák of the Sapientia Hungarian University of Transylvania later conducted a detailed examination in 2024.
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Speaking to the Metro about the discovery, Urák said, “It is a unique case of two species cohabiting within the same web structure in this huge number: approximately 69,000 Tegenaria domestica coexist with about 42,000 Prinerigone vagans on this single large web.”
Reflecting on the find, he added that it inspired “admiration for nature’s ingenuity… respect for the magnitude and wisdom of the forces that shape it; and gratitude for having had the opportunity to see and even touch it firsthand.”
