A new cave spider, discovered in Indiana in 2016 has now been identified as a new species of arachnid and named after its finder in 2023.
It may come as a bit of a surprise that a scientist discovered a very small arachnid in a cave. Perhaps a jungle, a forest, a mountaintop, or even suburbia would make more sense since many people are not aware that cave spiders even exist. It is potentially hazardous for larger spiders which makes it all the more interesting that these extremely small spiders have chosen a wet, flood-prone, muddy cave to call home.
There aren’t many creatures that throw out the welcome mat and call a cave their warm and cozy home. Let’s face it, caves are chilly, wet places that stay dark and mostly uninhabitable all of the time. Why would anyone want to live there? This itty bitty Indiana arachnid does call it home and has gone unnoticed for a very long time because of it.
Meet the Smallest (So Far) Cave Spider
A new cave spider discovered in Indiana (Islandiana lewisi) female is 2mm long.
This microscopic arachnid looks like the usual eight-legged wonders, only it’s a bit transparent and down to live in chilly caves. The Indiana cave spider (Islandiana lewisi) is extra small at 2 millimeters and easy to miss since its body is a fairly transparent tan and would blend in well with a cave wall.
Julian Lewis, a cave researcher and president of the Indiana Karst Conservancy, found this very tiny arachnid while spelunking in a flood-prone cave. Lewis then informed arachnologist Marc Milne, an arachnologist at the University of Indianapolis, about finding the spider, and he went to check out southern Indiana’s Stygeon River cave for himself.
Once inside the cave, Milne saw horizontal sheetwebs hanging between boulders in the main room of the cave. Upon further inspection, Milne saw many tiny spiders that would later be formally and scientifically named Islandiana lewisi by the arachnologist. This new species of sheet-weaving spider received its name after Lewis since he was the official finder. This little spider is the fifteenth in its genus and the fifth added that it lives its life in a cave. It’s been 30 years since the last discovery in this genus.
This was the only species of spider that Milne found in the cave on his expedition, and the tiny spiders were in abundance. Since the cave is prone to flooding, it was particularly curious why they chose it to live and reproduce. Milne believes the spiders have been living off springtails found in the mucky cave floor. There is plenty more to learn about these tiny cave-dwelling sheet-weaving spiders. The spider was originally misidentified, but when Milne went back months later to look again, he realized this was a new species entirely.
