With a leg span of only six centimetres and a body size of around twelve millimetres, the spider Sinopoda scurion is certainly not one of the largest representatives of the huntsman spiders, which include more than 1100 species. However, it is the first of its kind in the world without any eyes.
“I found the spider in a cave in Laos, around 100 kilometres away from the famous Xe Bang Fai cave,” reports Peter Jäger, head of the arachnology section at the Senckenberg Research Institute in Frankfurt. “We already knew of spiders of this genus from other caves, but they always had eyes and complete pigmentation. Sinopoda scurion is the first huntsman spider without eyes.”
The regression of the eyes is attributable to living permanently without daylight. This adaptation was also observed in other cave-dwelling spider species by the Frankfurt arachnologist. “The Sinopoda species described demonstrate all kinds of transitions to cave adaptation – from eight functioning eyes to forms with six, four and two lenses, right up to blind spiders,” explains Jäger.