Lichen Spiders (Pandercetes gracilis) blend superbly with the surface characteristics of their tree. They remain strategically hidden from predatory birds and simultaneously well-positioned to ambush unsuspecting insects. Poorly disguised individuals are readily picked-off and the gene pool is progressively refined.
The close-up image (above) shows the orientation of the eight eyes; four looking down the surface of the tree, two looking back up the tree and two looking outward.
I do wonder to what extent individuals are capable of modifying their appearance to suit the tree? Likewise, to what extent are trees of suitable character chosen for their conformity with the appearance of the spider? I do know that egg-sacs are disguised by the spider through the deployment of silk of different colours, but what of the spider itself?
In the image below, a collection of lichen spiders shows an array of varied colours and patterns that suit a diversity of bark types.