Biologists have uncovered the secrets of these ‘Invisible’ animals
While walking through Peru’s rain forest, an eight-hour boat ride from the nearest jungle habitat, biologist Aaron Pomerantz saw seemingly small invisible jets zipping up. the road. “I went out there with a net trying to get things,” he said, “and it just changed direction and disappeared.”
This was his first close encounter with clear-winged butterflies, insects that live in the forests of Central and South American and have a unique way of camouflage: see-through or “glass” wings which makes it even harder to see in the thick bottom.
“It’s like the power of invisibility,” says Pomerantz, lead author of a recent study on Journal of Experimental Biology which examined how clear wings develop. “If you can wear an invisible cloak, it’s much harder for predators to find you. In the marine environment there are many transparent species, but on land it’s not very common. And that really begs the question. , ‘What does it take to be transparent on the ground?’ ”
By studying the wings of the species Greta oto, also known as the glasswing butterfly, at various stages of pupal development, Pomerantz and his colleagues at the University of California, Berkeley, the Marine Biological Laboratory at Woods Hole, and Caltech have found several causes. There are changes in shape and thickness of microscopic scales that often produce different color patterns in a butterfly. A layer of small waxy columns also acts like an excess layer of antiglare.
If so this is a remarkable adaptation, no. “It’s improved a lot of times,” Pomerantz said. There are several hundred species of butterflies and moths with glass wings, he said. Although they represent only a small part of the order Lepidoptera, they make the most of the rare examples of such transparency on the ground. Glass cows, which exhibit different levels of skin translucence, are another example.
On the other hand, the ocean, emerges with visible species, from jellyfish and sponges to crustaceans, cephalopods, and even fish. Early in the summer of 2021, two rare sightings of a glass octopus were made on an expedition, aboard the research ship at the Schmidt Ocean Institute. Falkor, to the waters from remote Phoenix Island in the Pacific Ocean. Being invisible, it turns out, is more easily accessible at sea than on land, in part due to the visual and physical properties of the water.
“You can think of it like a piece of glass of water,” says marine biologist Laura Bagge. “That environment is more formless than land, and you don’t have to deal with gravity. That’s why most animals are a kind of watery, buoyant thing, with no backs or liquid structures needed. to live on the earth. ”
Think of that classic Cows scene-one from the shark’s point of view-where the silhouette of a swimmer stands in the light flowing from above. Where the sun shines, it’s easy for underwater predators to spot irregular shapes, so being clear can help you get through. Deep in the ocean it remains useful because even in the aphotic zone – the depth where little or no sun penetrates – many bioluminescent animals release themselves, according to Bagge.
Now a senior biologist at Torch Technologies in Florida, Bagge was attracted to animal transparency on a research cruise for his Duke University dissertation. He dipped his hand into a bucket of sea creatures and took out a mysterious specimen. “It’s hard, like a lobster, but it’s a perfectly clear animal,” he said. It’s a shrimp -like crustacean, Cystisoma, which can grow as much in the hand of man. “They are very cold because they have hard skin on the outside and are full of muscle. How do you clarify this? ”