On the border between Albania and Greece, in a sulfidic cave (Sulfur Cave), a gigantic spider web has been discovered by a team of international scientists (including one BLU member).
This web is built by the house spider (Tegenaria domestica), a species common throughout Europe, including Belgium, where it is frequently found in garages, basements, and attics. But while this species is normally predatory and solitary, in Sulfur Cave this same species builds a gigantic communal web. Some 70,000 Tegenaria domestica spiders live there, just a few millimeters apart, without devouring each other.
Even more astonishingly, around 40,000 individuals of another spider species (Prinerigone vagans) are also found there. This peaceful coexistence between more than 110,000 spiders of two different species on the same web is unique and can probably be explained by the abundance of food.
The web is located in close proximity to a sulfidic stream, on the surface of which bacteria that oxidize hydrogen sulfide multiply. These bacteria are consumed by chironomid larvae (small mosquitoes) which, when they transform into adults, fly away and are devoured by the spiders. Such an abundant source of energy is unusual in caves, which are generally energy-poor environments, and could represent an analogue of chemoautotrophic ecosystems possibly found on other planets in the solar system and beyond.
https://doi.org/10.3897/subtbiol.53.162344
