Photographer Nicky Bay has been documenting an arachnid he calls the mirror spider for past few years. He’s noticed that when the spider feels threatened, it can shift the mirrored plates on its abdomen to reveal itself and make itself look bigger, like a cloaked Klingon ship uncloaking for battle.
For several years, I have been observing the odd behavior of the Mirror Spider (Thwaitesia sp.) where the “silver-plates” on the abdomen seem to shrink when the spider is agitated (or perhaps threatened), revealing the actual abdomen. At rest, the silver plates expand and the spaces between the plates close up to become an almost uniform reflective surface.
Many animals have evolved the ability to camouflage themselves and I’d speculate that is what’s happened to the mirror spider. The mirrored surface reflects the spider’s surroundings and turns it somewhat invisible to potential predators. The mirror system is more complex than an abdomen matching the green of a particular plant, but is also more adaptive — the mirror works equally well on green leaves, brown branches, and black soil. (via colossal)
Update: I misread Bay’s explanation of the spider’s response to threats and have corrected it above. I previously stated “that when the spider feels threatened, it can shift the mirrored plates on its abdomen to make itself appear more reflective”, which is exactly wrong. (via @RLHeppner/status/780921795335581696)