Battle of Marine Superpowers: In Sea Creatures, Sneaky Camouflage Wins Over Super Vision
In the wild, every advantage counts. For sea creatures, it's between the predator blessed with super sight and those who can seamlessly blend in the surroundings. Who wins? New research has the score.
Team Super Sight
According to a release by Duke University in Eurekalert, certain fishes can do the disappearing act with silvery scales that act as mirrors of their surroundings. However, scientists have long believed that there are animals who can counter this ability with their own power of seeing a distinct property of light called polarization. What's invisible to man's eye may not be to them.
Octopuses, squid, shrimp, other crustaceans and some fish like trout and salmon all have what's dubbed as polarization vision. Sonke Johnsen, biology professor at Duke University, described it as similar to having polarized sunglasses on. He is also the first author on the new study that observes how well animals see reflective camouflage under the sea.
The new study published in Current Biology gives the edge to marine life who can blend in the background. Researchers dove in the waters around the Great Barrier Reef and snapped photos of the "invisible" fish from six to 10 feet away. These include fishes like tuna, amberjack, barracuda and queenfish.
The photographs are key to understanding as the scientists used a special camera with tiny polarizing filters built into the sensor. By measuring the polarization state and the brightness of the light against the mathematical model of visual perception, the scientists were able to determine how far away these invisible fishes can be seen from with polarization vision.
It turned out that polarization vision doesn't help animals see the camouflage fish from a greater distance than they can if they didn't have their special power. According to a report from Scientific American, insects with such eyesight can find their way home with the polarized light of the sky as well as use it to find food and mates. At sea, the significance of this ability is now less clear-cut.
"There's a lot polarized light underwater, and there are all these ocean animals that can see it, but we have no idea why," Johnsen pointed out.