Madrid, 28 (Europe Press)
The only live photography of giant deep-sea squids is possible with red lights and a faux bait.
Asñi revealed this in a new study by Dr Edith Weidair, of the Oceanic Research and Conservation Association (ORCA), whose team made the scientific breakthrough in 2012.
The giant squid is the largest invertebrate on Earth, reaching a total length of 14 meters. Although most of the squid’s body consists of its long, twisted tentacles, you might think that an animal of this size would be easy to spot. However, giant squid live at depths of over 400 meters, as very little sunlight penetrates. To adapt to semi-permanent dark conditions, giant squid have developed the largest eyes in the animal kingdom. Up to 12 inches in diameter, these food plate-sized eyes are sensitive enough to see in dim light. In fact, the authors of this study believe that giant squid eyes could have such good vision that they were able to spot and avoid most submarines or underwater cameras previously used to attempt photographing this species.
To design a camera that giant squid cannot see, Widder used dimmed red lights in place of the traditional bright white lights that most deep-sea submarines or underwater cameras use to penetrate dark like ink. Since most squid cannot see red light, these cameras will be nearly invisible to any squid nearby.
Watching these giants takes more than stealth. There must also be a way to attract them close enough so that they can be photographed. To tackle this issue, Weider thought again of the wonderful eye of giant squid. Although the bright white lights likely scare these animals away, giant squids often hunt deep-sea prey that create their own light, called bioluminescence. So Widder built a lure called E-Jelly that mimics the vivid display of a deep-sea jellyfish (Atolla sp.). E-Jelly ‘s neon blue screen will suggest a meal nearby and hopefully, the squid close enough to be caught with the camera.
The use of red lights and the taste of E-Jelly was clearly a successful combination, and this technology was fundamental to the first images of live giant squid in Japanese and American waters. In addition, the authors of this study also reported several other species of squid, each of more than 1 meter long, that were successfully imaged with this technique in the greater Caribbean.
The effectiveness of this groundbreaking technique for photographing large deep-sea squids has the potential to continue to produce increasingly compelling images of mysterious and unknown species. However, perhaps most importantly, it could also provide new scientific insights into the behavior, distribution, and threats these animals may face. Without this information, we simply don’t know whether giant squids, like many other deep-sea species, are able to adapt to growing threats such as climate change or marine pollution, the researchers say in their study published in Science Direct.
As Dr. Nathan Robinson, senior fellow at the Cape Eleuthera Institute and lead author of this study, said, “Without this information, the future of this mysterious species will remain uncertain.”