Researchers in New Zealand have discovered three new shark species that glow in the dark.The study, published in the Frontiers in Marine Science journal, explains how the kitefin shark, the blackbelly lanternshark, and the southern lanternshark were found during a survey off the Chatham rise, an oceanic area off New Zealand’s east coast, in January 2020.
Among the three glowing sharks, the kitefin shark is now the largest-known luminous underwater creature and it can grow to 1.8 meters in length. It is usually found swimming 300 meters below sea level and preys on smaller sharks, ground fish and crustaceans.
Though light emission has been documented before in a range of aquatic life, including jellyfish and squids, the discovery is the first time scientists have been able to find proof of bioluminescence in sharks.
The three shark species all live in what is often called the ocean’s “twilight zone,” ranging between 200 and 1000 meters below sea level.Facing an environment with no place to hide, the sharks appear backlit against the bright surface of the water leading researchers to suggest that the sharks need the blue glowing camouflage to fend off potential predators and capture prey for survival.
However,further research is required to uncover why the kitefin shark is luminescent given the species has few or no predators unlike the other two species recorded. Scientists speculate the slow-moving shark uses its natural glow to illuminate the ocean floor while it hunts for food, or to disguise itself while it approaches prey.