Why do deep-sea fish look like aliens?
Many fish lurking in the ocean’s depths look like the aliens from horror movies, sporting glistening teeth, glowing-in-the-dark bodies, and bulging eyes. Why do these fish sport such bizarre appearance?
The peculiar appearance of deep-sea marine fish is, in large part, a reflection of the harsh environment they live in. Most of the deep ocean, which starts 656 feet (200 meters) below the surface, has little to no light, high-pressure systems, low food availability, and is much colder than the rest of the ocean, with an average temperature just above freezing at
“The deep sea is a really harsh place to make a living, so a lot of animals have really had to adapt some niche adaptations to survive in that environment,” Mary McCarthy, a biologist for fish working at Monterey Bay Aquarium in California, said on Live Science.
In the absence of many opportunities to locate food, deep-sea fish have developed characteristics to assist in capturing prey, with one of the most terrifying being jaws with massive size. For instance, the Sloane’s viperfish ( Chauliodus sloani) has fangs too large to shut its jaw without causing damage to its brain. The teeth of these razors are transparent, meaning they can hide their weapons from predators until they’re too late. Other deep-sea fish, like Pelican Eels ( Eurypharynx pelecanoides), have mouths that, when stretched, take up most of their body to ensure they can catch and eat colossal fish that they can find in the deep-sea food deserts.
Underwater light show
Certain predators in the deep sea possess a weapon that makes them a prey magnet: bioluminescence, which is the capability to produce tight. For instance, this female seadevil or marine fish is one of the species featured in 2003’s computer-animated movie “Finding Nemo.” These creatures that cause nightmares catch prey by putting a glow-in-the-dark light at the tip of a rod anchored on their head, similar to the bait on an end pole for fishing. This light canary because marine creatures might think they are about to take a bite of a glowing creaturely; they’re just likely to be eaten by the predator).
However, luring prey into the water isn’t the only benefit of bioluminescence. This phenomenon is evident in over 75 percent of deep-sea species, according to the findings of a research study published in Nature conducted by researchers at the Monterey Bay Aquarium Research Institute. Certain pelagic fish, like the giant hatchet fish ( Argyropelecus gigas), can dim and brighten according to their environment’s lighting and use bioluminescence to hide from enemies.
Other species utilize the ability “to help them find food, attract a mate, and defend against predators,” Edith Widder, an ocean biologist and the founder of the Ocean Research & Conservation Society environmental group based in Florida, said on Live Science. Widder has been on several submersible dives to study deep-sea bioluminescence. She also examines the underwater phenomenon compared to “Van Gogh’s Starry Night, but in three dimensions.”
Most of the time, the light show is caused by a chemical reaction in the fish’s body, in which a compound that emits light called luciferin is combined with the enzyme luciferase to produce an image of light like “when you break a light stick,” Widder explained.
Another typical feature of deep seas is the squishiness. It is found in waters that are outside Australia and Tasmania. The species known as the blobfish ( Psychrolutes Marcus) is located at depths ranging from 1,970 to 394 feet (600 and 1,200 meters), and the pressure is over 100 times greater than at the top. The blobfish developed a floppy body with no skeleton to endure this debilitating stress. This is why, when the fish is exposed to the sun, it shrinks and transforms into a gelatinous beast with a face framed by a constant frown, earning it the title ” world’s ugliest animal” in 2013.
Or is it just ordinary?
The ocean covers over 70% of the globe, making the deep sea one of Earth’s most extensive living spaces. Instead of asking why creatures in deep seas look strange, we land residents should ask an alternative question: Are we the odd-looking ones?
“Because [the deep sea] is dark, because it is cold, because it is oftentimes low oxygen, it’s kind of like the opposite of or what we’re used to,” McCarthy stated. “But it is like the biggest environment on Earth, and so it’s normal for them, but it’s just weird to us.”