Masters of Camouflage
Check out this beautiful conch shell …
… Well, actually it’s an octopus.
Octopuses have long been known to be able to change color and pattern to match their surroundings and hide from predators. But while other cephalopods can also use color and pattern to blend into the background, it turns out that the octopus can go one step further: they can take on the appearance of something in particular, like a shell, a fish or a plant.
“By reproducing key features of well-chosen objects, the octopus can produce an effective camouflage that may fool a wide range of potential predators,” Noam Josef, of Ben-Gurion University in Israel, and his colleagues write in a study in the journal PLoS ONE.
The researchers studied 11 octopuses in the Red Sea and the Mediterranean Sea to see how they could fool the eyes of different kinds of marine creatures with different visual systems, as well as to enable the octopus to be hidden from all angles – all of which calls for very complex camo.
Octopus cyanea and O. vulgaris base their body patterns on selected features of nearby objects rather than attempting to match a large field of view. Such an approach enables the octopus to camouflage in partly occluded environments and to solve the problem of differences in appearance as a function of the viewing inclination of the observer.
Conventional thinking … is that an octopus attempting to camouflage itself in complex and colorful surroundings typical of coral reefs faces two main options: it can imitate the overall characteristics of its close surroundings or it can choose to imitate a certain object and its characteristics. … The analysis presented here shows that when camouflaging, an octopus samples specific features of selected structures in its surroundings, i.e., it performs “deceptive resemblance,” sometimes referred to as element imitation (as opposed to object imitation).
However, the octopus does not imitate the object precisely … but rather uses key features of the objects common in its surroundings. A possible advantage to such a mechanism is that it can fit a wide range of locations even if the exact level of the match is not perfect.
One other thing about octopuses, incidentally: They’re colorblind!
See the whole study here.
Posted May 25, 2012, by Michael Mountain