Organisms have an invisible way of becoming transparent so that light passes through the body. To do this, the body must have tissues that do not disperse or absorb sunlight. The natural world is full of living examples.
Behavioral ecologist James Barnett of McMaster University in Canada commented of glass frogs: “Transparency is the perfect camouflage. Transparent bodies are relatively common in aquatic species, where animal tissue has the same refractive index as the surrounding water.
Many sea and microscopic creatures take advantage of the transparency to hide where there is nothing but water like jellyfish, sea snails and a wide variety of baby fish.
“Air and tissue have quite different refractive indices, so transparency should be less efficient than for terrestrial species. shallow is very rare “.
But some land plants and animals have also evolved to have at least part of their body transparent. Here are six species with their transparency abilities and stealth strategy.
The transformation of glass ink
In addition to the eyes and stomach, glass ink is almost completely transparent.
Biologist Sönke Johnsen, Woods Hole Oceanographic Institution, USA explains: “The eyes and intestines of glass ink cannot be transparent. The eye has to absorb light for observation, and the intestines are exposed by the food it contains, as even transparent prey is visible during digestion.
But squids also have tricks for dealing with the opaque fragments on their body. The eyes of at least one of the 60 species of the glass squid family use a combination of light-emitting organs called photovoltaic cells and reflective cells to deflect this light. Together they create the illusion of sunlight filtering through the water.
To minimize visibility of the digestive organs, the squid places the digestive organs vertically while the squid swims horizontally along the body. When swimming, the level of the glass also raised the hand parallel to the digestive organs to hide. Swimming in this manner minimizes the squid’s shadow in case the squid accidentally crosses paths with a hungry predator.
Glass ink can also transform into a sphere as a defense mechanism, pulling the head and arms into their mantle.
Glass frog and mixed armor
Like the squid, the intestines of the glass frog (family Centrolenidae) are also clearly visible through the transparent abdomen, but they are not seen from below by predators. The partial transparency of this species makes it possible to complete its camouflage because it holds its belly on the green leaves of the “house” vegetable forest.
Its clear belly helps the amphibian to adjust the brightness according to the light level of the selected location. The frog’s limbs are also translucent, blurring the lines between it and surrounding areas, for better concealment.
Transparent crustacean with 12 tiny retinas red eyes
Instead of creating an illusion of light, transparent-bodied species have different strategies to hide their visible eye tissue, such as crustaceans that camouflage the retina to match the color and brightness of the surroundings. The deep-sea animal (Paraphronima gracilis) has eyes as large as 50% of its body. Evolution has found a way to make the creature’s giant orb-shaped eyes transparent, minus the 12 small red retinas in each eye.
The retinas are moderately spaced to make them less visible from below, while maximizing their sensitivity to downward light.
Moths with transparent wings
The coffee moth (Cephonodes hylas) has transparent wings and a plump body like a bumblebee. Its wingspan was 45 to 73 mm. The abdomen changes color from yellow to green, the third and fourth abdominal cavities are bright red.
To disrupt the surface’s ability to reflect light, moths use prominent transparent wings with the corneal surface of the eye for camouflage.
Transparent floating ribbons of eel larvae
Many juveniles start out as a transparent larva straddling the currents and the eel is no exception. Before ripening, the freshwater eel goes through the larval stage of leptocephaly and then the glassy eel stage.
They look like “floating ribbons” and try to make themselves as flat as possible. The thinner an object, the more light can pass without interference. It also makes them very difficult to detect.
The flower has a transparent shape when it rains
When the weather is nice, the Ha Son Diep flower, also known as the bone flower (Diphylleia grayi), looks like a typical white flower. The flowers grow in small bunches of blooms, appearing graceful as if showing their shape under green foliage. The special thing about this flower is that when it meets water, the white petals magically become crystal clear, revealing tiny veins on the petals like bones. But when they dry, they return to their original white color.
Their whiteness is not due to the pigment, but occurs when the rough surface of the petals and air gaps combine to reflect light, creating the illusion of whiteness. The refractive index between the transparent cell surface and the air pockets between the convex parts of the flower is sufficient to diffuse and reflect the light that shines on them, making them white.
But as the rain fills the spaces between the cells of the flower, the refractive indices of the cells and the vacuum become more consistent, allowing more light to pass through and we can see through them.
Whether or not this gives Ha Son Diệp Hạ Sơn an evolutionary advantage is a mystery, but watching it is very beautiful.