It is believed that the illumination of the squid resembles moonlight and hides the silhouette of the mollusk from the eyes of predators. Where does this light come from? Only hatched squid are sterile. Their luminescence organs do not work and are covered with mucus and cilia on the outside. Them begin to attack different bacteria. But the luminescence organs are intended only for luminescent bacteria Vibrio fischeri. When they are collected more than 5, they turn on a variety of squids genes number! As a result, the necessary bacteria are populated inside the lacuna, and pathogens can not penetrate. The outer tissues of the squid are transformed into a landscape that attracts relatives and repels predators. And the author of this discovery, McFall-Ngai, summarized: "The result of these studies was the first experimental data showing that a certain bacterial symbiont can play a leading role in the development of the animal."