The Mystery of the Largest Light in the Sea
This giant squid has the world’s biggest light-producing organs. But why?
A quarter-mile below the ocean’s surface, in the borderless realm of the midwater, two blue-green orbs illuminate the inky black.
They glow for a few seconds then disappear. When they return, it’s for the same duration. The same disappearance. It’s a signal, a message, the morse code of an ancient language of light.
Friend or foe? Rival or mate? I am here, I am this.
These orbs belong to Taningia danae, a species of deep-sea squid who can grow to more than seven feet in length and weigh more than 130 pounds. Also known as the Dana octopus squid for their eight arms and lack of feeding tentacles, these animals glide through the depths on a pair of huge muscular fins that unfurl from their maroon-colored body, or “mantle.”
Their arms are lined with two rows of sharp retractable hooks. And, like most deep-sea squid, they are adorned with light organs called photophores. They have some on the underside of their mantle. There are more facing upward, near one of their eyes. But it’s the photophores at the tip of two stubby arms that are truly unique. The size and shape of lemons—each nestled within a retractable lid like an eyeball in a socket—they are by far the largest photophores known to science...
https://nautil.us/the-mystery-of-the-largest-light-in-the-sea-308189
