Scientists Discover Glow-In-The-Dark Sharks Off New Zealand
Scientists have found three sharks off the coast of New Zealand that glow-in-the-dark.
The bioluminescent species include the blackbelly lanternshark, southern lanternshark and the kitefin shark, which, at nearly six feet, is the largest luminous vertebrate ever discovered.
Bioluminescence is a natural phenomenon in which organisms produce and give off their own light. This behavior is observed in fireflies, fungi, and many marine species, including jellyfish, squid, crustaceans and fish.
According to a recently published study, the deepwater sharks were collected from the Chatham Rise, east of New Zealand’s mainland, in January 2020. Scientists knew the species existed but had not observed them emitting light.
The three species live in the mesopelagic zone, aka the “twilight zone” of the ocean, which stretches from about 650 feet below seawater to over 3,000 feet deep, the point at which natural sunlight can no longer penetrate.
There are many reasons animals may emit light. In the case of the two lanternsharks, their glowing bellies may provide camouflage. In their open-water environment, there’s nowhere to hide from danger, but by blending in with the ambient light coming from above the water’s surface, they can avoid predators that may be swimming beneath them.
The kitefin shark has few natural predators, so researchers were a little more puzzled as to why it was glowing. It may be that the kitefin uses bioluminescence to light the seafloor while it hunts or to camouflage itself when approaching prey.
“The luminous pattern of the Kitefin shark was unknown and we are still very surprised by the glow on the dorsal fin,” Jérôme Mallefet, a lead researcher, tells The Guardian. “Why? For which purpose?” He hopes to return to sea to conduct more research and search for other luminous creatures soon.