What is the strangest animal ever discovered in the sea? wow boy. We have options.
Even the sea creatures that people tend to be familiar with are pretty weird. Take the flounder, with their flattened bodies and folded eyes, or oysters, which appear to be, let’s face it, mostly mucus? And what about whales? Are we all okay with the concept of baleen?
But it only gets weirder. On coral reefs and in deep water sources; on the mid-ocean ridges and in the cold, dark depths, animals have evolved some truly bizarre bodies and habits to survive. The result is creatures as alien as anything that could ever be found on a distant planet. Sea creatures survive without light, almost without oxygen, under incredible pressures – wherever they can survive.
So who’s the weirdest? We asked several marine biologists to find out.
Related: 10 Strange Creatures Found Under the Sea in 2021
coral reef creatures
coral reefs are home to thousands of species, so it’s no surprise that some are very strange. Coral itself is pretty weird; after all, reefs are built by coral polyps, relatives of jellyfish that extract calcium carbonate from the water to build protective homes in the shape of brains, fans and plants. Even stranger, most coral polyps would not survive without a symbiotic relationship with an alga called zooxanthella, which lives inside the polyps and provides energy via photosynthesis in exchange for shelter and carbon dioxide.
The animal-built habitat of a reef, in turn, harbors other strange creatures. Take the pink veiled fairy wrasse (Cirrilabrus finifenmaa), which lives in deep, poorly lit reefs called “twilight reefs”. These fish look like something a 6-year-old with access to the 64-crayon crayon box can dream of: their bodies are a rainbow of pink, orange, purple, and blue. Research published in the journal Proceedings of the Royal Society B in 2020 discovered that coral reefs provide the perfect environment for the evolution of gaudy colors. The clear water allows males and females to see each other well, being able to develop colorful bodies to attract mates; the structural refuge offered by stony corals means that animals face less cost for their display than animals in more open waters, because they can more easily escape predators despite being quite visible.
Another common inhabitant of coral reefs is the bullet parrotfish (Chlorurus sordidus), which has some of the strongest teeth Earthaccording Smithsonian National Museum of Natural History – so much the better for chewing through the tough coral exoskeletons to get to the tasty polyps inside. As if this diet wasn’t weird enough, parrotfish also sleep in cocoons of their own mucus to protect itself from blood-sucking parasites.
Perhaps the strangest animals found on the reefs and coasts of tropical Pacific islands, however, are Sacglossans. Sacoglossan translates to “sap suckers,” said Jeanette Davis, a marine microbiologist, science communicator and author of children’s book “Jada’s Underwater Journey” (Publication Mynd Matters, 2022). Sacoglossus are more often known as “solar-powered sea slugs,” Davis told Live Science. These colorful slugs feed on algae, stealing some of the algae’s chloroplasts, cellular organs that allow photosynthesis. Yes, these slugs can collect energy directly from the sun. They can also use molecules from algae for defense, and some of them can also help defend human health.
“Through my work as a marine microbiologist, I worked with a team of scientists to help discover an anticancer compound produced by an algae-associated marine bacterium that is sequestered by a Sacoglossan and used as a defense molecule,” Davis said. he said.
Floating in the depths
The open waters of the ocean are not as teeming with life as coral reefs. But what lives there is almost universally strange, especially in the darkest, deepest regions. Making a strong case for the absolute weirdest are siphonophores.
“People struggle to understand siphonophores,” said Steven Haddock, a marine biologist at the Monterey Bay Aquarium Research Institute who studies these oddities as well as other gelatinous creatures. Siphonophores function as a single organism, but are actually colonies of individual asexually reproducing organisms that take on different roles within the greater whole. Australian researchers once observed siphonophores up to 150 feet (45 meters) in length. Haddock told Live Science that his favorite siphonophore is erenna sirenawhich uses red bioluminescent baits to attract prey.
Another gelatinous favorite for Haddock is bloody comb jelly (lampoctiles), a deep-water ctenophore. Ctenophores do not sting like jellyfish; instead, they sport sticky cells to trap prey. The eerily named Bloody Belly Comb Jelly is bold red and propels itself through the depths with tiny cellular projections called cilia, which seem to glow when light hits them.
Also resplendent in red is the strawberry squid (Histioteuthis heteropsis), a resident of the ocean’s twilight zone. It has a large (and surprisingly green) eye that looks up to detect shadows cast by prey, and a small eye that looks down, looking for signs of bioluminescence from prey swimming below. Strangely, however, the strawberry squid does not match the bigfin squid (magnapine)that has a body the size of a dollar bill and tentacles the size of a human. These distinctive squids are known for their tentacles that bend at a 90 degree angle, creating an odd “elbow”. They have only been sighted about 20 times since their discovery more than a century ago.
life in the background
Animals that hope to survive at the bottom of the sea must be without light and withstand the incredible pressure of thousands of meters of water. Famous residents include the bubble fishwhich looks quite unassuming when swimming thousands of feet below the surface, but deflates into a flabby bag when brought to the surface, where the pressure is 100 times less than what the fish is adapted to.
Scientists are just beginning to catalog the other strange creatures deep in the ocean. Javier Sellanes López, a marine biologist at the Universidad Católica del Norte in Chile, has been exploring seamounts off the coast of South America, discovering a number of new or poorly understood species. Takes Eunice Decolorhami, a polychaete worm found living in tubes 180 to 340 m deep on the slopes of the Desventuradas Islands and in the seamounts of the Nazca summit. With what appear to be bulbous eyeballs and a deep bite, these animals look more like background characters on “The Muppet Show” than sea worms.
The researchers also found samples of the mysterious white and red crab. Ebalia Sculpture, a bottom dweller that runs among tube worms and anemones about 650 feet (200 m) below the surface.
“His main distinguishing feature is a face carved into his cephalothorax. [fused head and body] that resembles the image of a being from the underworld,” Sellanes López told Live Science. In other words, it’s a devilish crab.
But let’s go deeper. Lisa Levin, a biological oceanographer at the Scripps Institution of Oceanography in California, named xenophiophores as one of her favorite strange deep-sea creatures. Xenophiophores are single-celled organisms called protozoa that assemble sediments to form elaborate houses called “tests”. These tests look a bit like plants, corals, or large lichens. They are found below about 1,300 feet (400 m) well in deep ocean channels like the Mariana Trench and, in this barren world, provide shelter for invertebrates and developing fish embryos, Levin told Live Science.
“I think the fact that a protozoan could harbor invertebrates or provide a nursery habitat for snails is a delightful idea,” Levin said.
Less delicious, perhaps, are the bone-eating worms (osedax), a deep-sea oddity suggested by Scripps Institution marine biologist Gregory Rouse. These red feathered worms eat without a mouth or guts, instead excreting acid to break down the bones of dead marine animals. Females grow to about 2.5 centimeters in length. Males are only one-twentieth of an inch (1 millimeter) long and live in gelatinous tubes clinging to females, existing only to fertilize female eggs.
So what’s the weirdest sea creature of all? It could be a crab carved with the face of Satan, a gelatinous bioluminescent thing that is actually a bunch of little things, a slug that photosynthesizes, or a worm that pierces bone with acid. Or maybe it’s something else. If there’s one guarantee in the ocean, it’s that something stranger is always just around the corner.
Originally published on Live Science.