“Happiness is found even in the darkest of times, when one remembers only to turn on the light,” Albus Dumbledore once told Harry Potter. One might like to think he was talking about our deep oceans, often described as a cold, dark kingdom that is too far away to see the warmth of the sun. However, even though very little sunlight falls down to this zone, there is light. Plenty of light!
Biomonomy, defined as the representation and emission of light by a living organism, captures the imagination of many, making the sea shine like the bright stars that orbit our little blue planet. . Biomass organisms live throughout our ocean water column, and in the deep ocean it seems to be very common, making it the most common means of communication on our planet.
Photographs of bioluminescent sharks taken as part of the research in New Zealand waters.
Jérôme Mallefet1 / Frontiers in Marine Science
So it would make sense that some shark species are dark in the dark. Among the Squaliformes the order of sharks, bioluminescence was recorded for two families at deep sea: Dalatiidae and Etmopteridae, with a third (Somniosidae) has recently been added to the list as a result of the velvet fish (Zameus squamulosus) made it clear to us recently that, it is light. Sharks are not a new sight, with the first mention of shark light scattering going back as early as the 1840s. However, because scientists have so much to learn about sharks, we are still learning which species are light. That is why it is so encouraging that Kiwi and Belgian researchers studying sharks off the east coast of New Zealand have discovered three species that glow – including the bone- The best known luminescent dove, the kitefin shark (Dalatias licha). Also known as the seal shark, it is a deep-water shark that can sharpen pieces of meat like their famous cooked shark relatives. Most reach about 47 inches (120 centimeters) in length although they are thought to measure up to 70 in (180 cm); they have beautiful green eyes to see their intended prey of mesopelagic and native fish, cephalopods, crustaceans and polychaete worms.
All three species of shark, including black lanterns (Etmopterus lucifer) and southern lanterns (Etmopterus granulosus) samples, living in the ‘evening zone’, which is between 656 – 3281 feet (200-1000 meters) deep. Collected as a bycatch from a hoki trawl survey by the NIWA Tangaroa vessel last January, they were uprooted from the depths of the Chatham Rise off the east coast of New Zealand’s South Island (Māori: Aotearoa). The Chatham Rise is a large underwater plateau extending 870 miles (1,400 kilometers) east of Banks Point and has been described as an “area of biological interest” due to its support for a number of large commercial fisheries. and is perhaps an important young land for a number of marine species.
Many can enjoy biofouling in the form of shiny waves, too, not just shining sharks!
Getty Images
Thanks to NIWA scientist Darren Stevens and Belgian scientists Dr. Jérôme Mallefet and Dr. Laurent Duchatelet, the luminescence team was able to record these three shark species for the first time. Prior to this discovery, no-one had recorded bioluminescent sharks in New Zealand waters! During the trawl, the researchers examined 13 kitefin sharks, 7 black-billed sharks, and 4 southern lantern sharks, which were kept alive in a cold dark room on board. Here they were to take sex, measure, weigh and photograph them. It is believed that 57 out of 540 of all known shark species emit bioluminescent light.