It has been years since bioluminescent fish are a total mystery for scientists. Moreover, it seems that there are many species out there.
These fish produce their own light through a chemical process inside their bodies. Nevertheless, scientists have not discovered yet how this can be possible. Around 1,000 to 1,500 feet underneath the ocean surface, these fish give a spectacular show of lights similar with blue stars.
According to Matt Davis, an ichthyologist at St. Cloud State University in Minnesota, sunlight cannot penetrate the water more than 30 meters. Therefore, because the depths of the ocean are completely dark, the only source of light comes from organisms that produce it with their own bodies.
Fish use this bioluminescence for many reasons, such as a defense mechanism, to attract prey, and to communicate with one another. For instance, the shining tubeshoulder fish uses a blob of bioluminescent goo out of its shoulder when it is attacked as a way of deceiving the predatory fish. This decoy gives the fish a brief moment which is enough for it to escape in the darkness.
Still, experts think that we should not be surprised just because a marine creature is able of creating its own light. It is already known that insects are capable of doing it too. Fireflies, for example, produce their own light through a chemical process in their bodies.
In their case, the light has other reasons, such as attracting females. Plus, shining in the darkness makes fireflies quite a target for predators, such chameleons, frogs and other reptiles.
It is also worth mentioning that the bioluminescent phenomenon is common among fungi and bacteria as well. Plus, it is thought that the light of the fish also has a reproductive role.
For instance, the barbeled dragonfish is one of the most famous bioluminescent fish that lives in the depths of the ocean. It has a long protrusion attached to its chin, called barbell, from which the name was taken. This barbell is tipped with photophore, an organ capable of producing light.
In addition to this, this fish also has more photophores under its eyes and along the sides with which it communicates and illuminates prey.