The Ocean’s Glow

In a place so mysterious and eerily dark under the vast deep ocean, aquatic organisms have adapted to the extreme conditions of their environment through the natural production of light by their body. Sea creatures that produce bioluminescence, such as the anglerfish, atolla jellyfish, and black dragonfish, have the advantage of using this light to defend themselves from predators, hunt for prey, and attract potential mates, all of which aid in the survival of these creatures. As fascinating and otherworldly as this ability may sound, how exactly do these organisms produce light all by themselves in a place that is completely absent of sunlight? The answer can be found in the symbiotic relationship between some aquatic organisms and the bioluminescent bacteria that are present underwater. One of the many creatures that is involved in this symbiotic relationship is the Hawaiian bobtail squid. This type of squid possesses a light organ, a place within the squid’s body where the bioluminescent bacteria Vibrio fischeri live and reproduce. While the bobtail squid provides the V.fischeri bacteria with the nutrients that they need in order to convert chemical energy to light energy through quorum sensing, the V.fischeri bacteria produces the bioluminescence that allows the squid to blend in with their environment; this method of camouflage is called counterillumination.