In reply to: The Lovely Tale of an Adorable Squid and Its Glowing Partner - The Atlantic
In the wild, shortly after hatching, these squid would normally be colonized by microbes. But they are selective about their partners: Of the thousands of species of microbes in the ocean, only one—Vibrio fischeri—is allowed to enter the squid’s body. Once inside, it begins to glow. And that glow, it is said, perfectly matches the moonlight welling down on top of the squid, masking its silhouette from predators looking up from below. The bacteria provide the squid with a kind of luminous invisibility cloak.