There is so much we don’t know about the ocean, about 95% of it to give you an idea. For all we know aliens could be living below the surface. Some scientists are even suggesting that the best place to learn about extraterrestrial life is in our oceans. Personally, I couldn’t agree more as one of the most fascinating forms of communication exist underwater, that is by glowing light.
Bioluminescent species like bacteria, algae, small crustaceans, squid, jellyfish, and fish can be found throughout the ocean. Most tend to live in the deep sea where sunlight can’t reach. What’s mind-blowing is how these creatures generate light with their brainpower! In response to its needs, the body creates a chemical reaction that controls the light intensity and the color of its bioluminescence.
Glow in the dark creatures manipulate light as needed. Female angler fish lure its meal by dangling light close to its mouth. Squid, on the other hand, use it when in danger. Squirting ink becomes useless in a dark environment, so some species bedazzle their predators with glow-y bioluminescent liquid. On the seafloor, Annelid worms defend themselves by illuminating as a distasteful meal to its predator. It reminds me of bright red tree frogs that use color to warn potential prey of their deadly toxins. Other creatures like ‘Flashlight Fish’ and ‘Ponyfish’ use light to differentiate gender and even to attract mates.
Most bioluminescent species give off a blue or greenish light. Over time some have evolved, mastering ways to manipulate their color. A good example is the ‘Barbeled Dragonfish’ which uses red light that many deep-sea creatures are blind to. Under the ‘invisibility cloak’ they can creep up to their prey or escape from danger unnoticed. Another impressive feature is what biologists call ‘counterillumination’. In the open ocean with no place to hide, ‘Firefly Squid’ and ‘Midshipman Fish’ erase their shadows by radiating light from their bellies. Blending in with the lighter background, their counterillumination mechanism makes it hard for predators that hunt from below to spot.
The tiny 5% of the ocean we know of is pretty surreal, and I bet the deeper we look the more otherworldly it’ll get. The possibility is as infinite as the horizon. Could glowing light possibly be our planet’s most used communication?
By Buranee Soh
Notes Edith Widder x Ted The weird and wonderful world of bioluminescence https://www.youtube.com/watch?v=IDkSDPgrtjs
Mysteries of the Deep with MBARI's Dr. Steve Haddock — Bioluminescence! https://www.youtube.com/watch?v=teB1FwdeOMg