The net - casting wanderer has eight eyes . But two of those peepers – the wanderer ’s junior-grade eyes – are particularly enormous , and scientists had never been able to explicate on the dot why they make out to be . accord to a new study published inBiology Letters , the reason is that those amazing eye assist the creature Richard Morris Hunt not only prey that flies , but also feed that fawn .
The spider is a lethal predatory animal that spin a web that await like a net . When prey make it , the arachnid strike within a thousandth of a endorsement , stretch the net to ensnare its victim . A squad led by Jay Stafstrom from the University of Nebraska - Lincoln camped in Paynes Prairie Preserve State Park in Florida for months to take in the internet - casting spider in action and prove the power of its visual sensation .
The team made a wanderer blindfold out of dental silicone to see whether the creatures could still hunt with their enormous lowly eyes cover , and used four closed - tour cameras to ascertain their progress . If the spiders hunted vanish prey , the blindfold has no significant burden on their hunting ability . But last - cast spider could not overtake crawling or walking fair game if they could n’t see out of their secondary eye . In fact , none of the blindfolded spider do to catch walking prey when they were blindfold , whereas one in four snagged a grab when the researchers did n’t cover their eyes .
The findings seem to suggest an answer to a vexing question about the spider , which is why they evolved such bombastic secondary eyes when most web - building wanderer did not . It admit a portion of vim to keep center respectable , and it guide disproportionately more vigor as those heart get big . " It ’s a really just representative of the Law of Diminishing Returns , where you ’re pass way too much to get just a little bit more entropy , " Stafstrom said astatement .
The field evoke that it ’s deserving it for the spider to grow fully grown optic because it avail them bump ground - based quarry . He also found the walking prey that meshing - shake off spiders snare was larger than the flying prey it caught , and more nutritious . In addition , Strafstrom and his colleagues also think that the oversized eyes countenance the spider to hunt solely at night and hide during the mean solar day by camouflage themselves against the palm fronds where they live . That nocturnal selection strategy is yet another reason that may explain what big eyes they have .
