Researchers studying sharks living in New Zealand waters have found that three deep-sea shark species glow in the dark, including one that is now believed to be the largest luminous vertebrate of all time. It is the species Dalatias licha, whose animals can reach 1.8 meters – which prompted the researchers to refer to it as a “giant shining shark”.
This is the first time that bioluminescence – the ability of living organisms to produce light through chemical reaction – has been documented and analyzed in the shark species Dalatias licha, Etmopterus lucifer (known as black-bellied shark) and Etmopterus granulosus (southern lantern shark).
The animals were found at Chatham Rise on the east coast of New Zealand in January 2020, and researchers from the Catholic University of Louvain, Belgium, and the National Institute for Water and Atmosphere (NIWA) in New Zealand took part in guaranteeing that the discovery had an impact on that Has knowledge the scientific community has about life under the sea – one of the least studied ecosystems on the planet.
A way of camouflage
Sharks live in the so-called mesopelagic zone or “twilight zone” of the ocean between 200 and 1000 meters depth. Seen from below, sharks are illuminated by the light reflected from the surface of the ocean, exposing them to possible predators. With that in mind, the researchers suggest that the fact that these three species of shark are bioluminescent (namely in the lower part of the abdomen) can help animals camouflage themselves from threats.
In the Dalatias licha species, which has few or no predators, experts believe it is possible that these sharks use their bioluminescence to illuminate the sea floor in search of food or to camouflage themselves as they approach prey .
In an article published in the journal Frontiers in Marine Science, the researchers say more study is needed to confirm these hypotheses and better understand how these animals’ bioluminescence works and what their main role is.
“Given the vastness of the ocean floor and the occurrence of luminous organisms in this area, it is becoming increasingly clear that the generation of light in the depths of the ocean must play an important role in structuring the largest ecosystem on our planet,” the respondents concluded.