November 21, 2011
What is that creature in this beautiful photograph? This animal is known as a "glass squid" (scientific name Leachia). Sunlight filtering down through the ocean water passes right through the glass squid - it is practically invisible in the light. There are both squid and octopus like this, and they can "hide in plain sight" in sunny water.
However, they do not do so well down in the ocean deep, where there is no sunlight. Down in the deep, there are dangerous predator fish whose bodies produce a bright light that they shine directly on the transparent animals, which become visible in the predator’s "headlight." The ability of these marine animals to produce their own light is called bioluminescence (BY-oh-loom-i-NESS-ens).
Somehow, their prey - the transparent squid and octopus - need to have a way to camouflage themselves down in the deep. Researchers at Duke University decided to find out how they do it. They captured some of the squid and put them into a dish full of cold ocean water and shone bright lights on them. They were amazed to discover that the squid switched on their camouflage instantly, changing themselves from clear to a spotted, reddish brown. With that coloring, they can hide more easily in their dark, deep-sea environment. The researchers were amazed to see how quickly they make the change.
If you are interested in seeing video of their experiment, click on the play button (at left) to see more.
Posted by: Seymour Simon
