Many deep sea creatures are bioluminescent. However, before documenting the luminescence of the kitefin shark, Dalatias licha, there has never been a nearly six-foot long luminous vertebrate creature. In a recent study, Mallefet and colleagues examined three species of sharks: Dalatias licha, Etmopterous lucifer, and Emopterus granulosus and documented their luminescence for the first time. These bioluminescent sharks are the largest bioluminescent creatures known.
Sharks are often known as one of the fiercest predators in the ocean. Yet they are also one of the most threatened marine species—largely because they are hunted by humans for their highly valuable fins. How do we know they are being threatened?
Traditionally, researchers have estimated the population and diversity of sharks using two methods. One is by sending divers into the water to count the number of sharks and record which species they see. Another is to set up baited cameras in different locations to record the sharks that come near. When fewer species of sharks are examined using these methods, we conclude that there is a decrease in diversity and an increase in what’s called “dark diversity”.
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