What’s cooler than a shark? A glowing shark!
Kiwi and Belgian researchers studying sharks off the coast of New Zealand (Aotearoa) have documented three deepwater sharks that are luminous.
The three species, the kitefin shark (Dalatias lichaI), the lucifer shark (Etmopterus lucifer) and the southern lantern shark (Etmopterus granulosus), all had similar photophores – a type of organ that appears as luminous spots. Each photophore contains a single photocyte – a light-producing cell – embedded in a cup-shaped groove with a lens (similar to that protecting the human eye) on top.
The sharks live in the ‘twilight zone’ of the ocean, which is between 200-1000 metres deep.
The trio have glowing underbellies, which the scientists suggest may be so they can camouflage against the bright surface of the ocean from fish inhabiting deeper water, as they write in their paper, published in Frontiers in Marine Science.
The kitefin represents the largest known luminescent vertebrate found to date.