The researchers believe that kitefin sharks, which have few if any predators, use their glowing ability to camouflage themselves from prey and to illuminate the ocean floor while hunting, but said more evidence was needed to confirm this theory.
Lead author Jerome Mallefet, of the University of Louvain-la-Neuve, Belgium, said the sharks used a different mechanism to glow than other bioluminescent animals.
"[They] control their light production system by hormones, while most of the bioluminescent organisms seen to date use nerve control to trigger their light," he told Belgian broadcaster RTBF.
The researchers concluded that bioluminescence plays a greater role than previously thought in deep-sea ecosystems.
"Considering the vastness of the deep sea and the occurrence of luminous organisms in this zone, it is now more obvious that producing light at depth must play an important role structuring the biggest ecosystem on our planet," the paper said.
Other luminous marine creatures include algae, crustaceans and jellyfish, and the ability serves different purposes for different species.
Some prey animals, such as jellyfish, use it to startle predators and attract other creatures that prey on their predators.
Other non-marine creatures, such as glow worms, use their light to attract prey.
There are also more than 75 known species of bioluminescent fungi, which only glow at night, attracting insects that land on them and pick up spores to spread in other areas.