Fluorescent animals. Who glows in the dark

"My Planet" talks about amazing phenomenon- luminous living creatures and where and when they can be seen.

About 800 species of creatures on the planet glow in the dark, like light bulbs. These are the well-known fireflies, and some earthworms, and underwater inhabitants — deep sea fish, jellyfish, squid. Some organisms glow constantly, while others are capable of only short flashes. Some shine with their whole body, others have special “flashlights” and “beacons” for this.

Light is used by organisms for a variety of purposes: to attract prey and mates, to camouflage, scare away and disorient enemies, or simply to communicate with fellow tribesmen.

The ability of living things to emit light is called bioluminescence. It is based on a chemical reaction caused by the presence of certain substances and accompanied by the release of energy. Scientists began studying bioluminescence only in late XIX century, and there are still many questions and mysteries in this area. We will tell you about the most amazing luminous creatures that inhabit our planet.

Fireflies

Representatives of the firefly family (there are about 2,000 species) create spectacular illuminations at night, using their light device on their abdomen to mate and communicate with each other. Not only adults, but also eggs and larvae are capable of glowing. Light of representatives different types differs in shades and character: from red-yellow to green, from continuous to pulsating. Many species of these beetles can regulate the light in their “bulbs”: shine brightly or dimly, gather together, flash and go out at the same time. Females of the American firefly Photuris versicolor are especially insidious: first they emit light signals to attract males of their own species, and after mating with them, they change their call signs to lure males of another species - for gastronomic purposes.

Using the example of fireflies, one can understand how the process of bioluminescence as a whole occurs: in the abdomen of the beetle there are photogenic cells containing small molecules - lucephyrins. Under the influence of a special enzyme, luciferase, they are oxidized and energy is released (the reaction requires the presence of oxygen, adenosine triphosphate and magnesium ions). In this case, the energy does not go into heating, as, for example, with an incandescent light bulb, but almost entirely turns into cold light. The efficiency of a firefly “light bulb” reaches 98%, despite the fact that an ordinary incandescent lamp can convert only 5% of the energy into light. The light from 38 beetles rivals the flame of an average wax candle.

In many countries, people used fireflies as light sources before Edison's invention. Aborigines of Central and South America decorated themselves and their homes with fireflies on ritual holidays. Amazon Indians tied fire beetles to their feet, hoping to scare them away with light. poisonous snakes in the jungle. The Portuguese, who colonized Brazil, placed beetles in lamps near icons instead of oil. Japanese geishas filled wicker vessels with fireflies to create spectacular night lights. Catching fireflies and admiring them is a long-standing pastime of the Japanese.

Where to see: for example, in June you can come to the Japanese farm Yuyake Koyake (half an hour's drive from Tokyo), where about 2,500 crickets live.

Jellyfish

The jellyfish Aequorea victoria became a celebrity thanks to the Japanese scientist Osamu Shimomura: he became interested in its glow back in the 50s, for decades he caught buckets of similar jellyfish and examined about 9,000 specimens. As a result, green protein (GFP) was isolated from jellyfish in the laboratory, which fluoresces greenish when illuminated with blue light. It seemed like a Sisyphean task until she showed up genetic engineering and there was no use for GFP: now this gene can be implanted into living organisms and see with your own eyes what is happening in the cells. For this discovery, Shimomura received the Nobel Prize in chemistry.

Where to see: off the west coast of North America.

Glow worms

Fluorescent worms live in Siberian soil. They have luminous points throughout the body, react with bluish-green light to various stimuli (mechanical, chemical, electrical), and are capable of glowing for up to ten minutes, gradually fading. Amazing worms, called Fridericia heliota, were discovered and studied by scientists from Krasnoyarsk. Having received a mega-grant to create a laboratory of bioluminescent biotechnologies at the Siberian Federal University, they invited that same Osamu Shimomura and were able to decipher the structure of the luminescent protein of worms and even synthesize it in the laboratory. This year they published the results of their many years of research. The scientists collected the worms themselves, shoveling tons of Siberian soil.

Where to see: in the Siberian taiga at night.

Mosquito larvae

Fungus gnats Arachnocampa spend from six months to a year of life in the larval state, and live only one to two days in the guise of a mosquito. As larvae, they weave silk into hunting webs, like spiders, and illuminate them with their own blue-green light. As a result, their colonies on the walls and ceilings of caves look like a starry sky. The hungrier the larvae, the brighter they glow, attracting prey - small insects.

Where to see: in Australian and New Zealand caves - especially popular with tourists different countries boat tours to Waitomo Caves.

crustaceans

During World War II, the Japanese collected small shell ostracods, Cypridina hilgendorfii, and used them for illumination at night. These natural light bulbs turn on very simply: just wet them with water.

Where to see: V coastal waters and the sands of Japan.

Fish

In the depths of the oceans live amazing luminous fish equipped with special organs - photophores. These are lantern glands that can be located anywhere: on the head, back, sides, around the eyes or mouth, on the antennae or processes of the body. They are filled with mucus, inside of which glow bioluminescent bacteria. It is curious that the fish itself can control the glow of bacteria by narrowing or dilating blood vessels - flashes of light require oxygen. The most interesting of glowing fish- deep-sea anglerfish that live at a depth of about 3 km under water. Females, which can reach a meter in length, have a special fishing rod with a “beacon” at the end: it is the light that attracts prey to it. The most advanced species of anglerfish, the bottom-dwelling galatheathauma axeli, has a light “bait” right in its mouth. She doesn't need to hunt - just open her mouth and swallow her prey.

Another colorful fish is the black dragon (Malacosteus niger). It is notable for the fact that it emits red light using special “spotlights” located under the eyes. The light is not visible to almost anyone deep sea inhabitants ocean, and the fish can calmly light its way without being noticed.

Where to see: deep in the ocean.

Squid

Among squids, there are about 70 bioluminescent species. The world's largest luminous creature is giant squid Taningia danae - scientists were able to see an individual 2.3 m long and weighing 60 kg. Light organs are located on its tentacles. Scientists suggest that the squid emits flashes of light in order to blind the prey and measure the distance to the target. In 2007, a team from the Tokyo National Science Museum filmed a fragment of the hunt of a giant squid that lives at depths of up to 1000 m.

Another amazing cephalopod is the vampire squid Vampyroteuthis infernalis. Because of its unusual luminous organs, it was separated by scientists into a separate detachment. In addition to two large photophores, it has small luminous “lanterns” throughout its body, and it can also release a light curtain consisting of numerous blue luminous balls from the tips of its tentacles. This powerful weapon in the fight against the enemy, it lasts up to ten minutes and allows the squid to hide in case of danger. Interestingly, the underwater vampire can adjust the brightness and size of the color spot.

Where to see: in early March, hordes of firefly squid Watasenia live in Japan near the coast of Toyama Bay. These small creatures live in the western part Pacific Ocean at a depth of up to 350 m and in the spring they come to the surface to spawn, staging a light show for tourists.

Fireflies

Fireflies, or pyrosomes, are marine free-swimming colonial creatures from the class of tunicates. They consist of thousands of small organisms - zooids. Each of them has bacterial luminous organs, thanks to which the entire colony luminesces with a bluish-green light, visible at a distance of more than 30 m. This animal, similar to a giant worm, swims with its closed end outward, and an adult person could easily fit in the internal cavity. The underwater monster can grow up to 30 m in length. Biologists call it pyros sea ​​unicorns, since they are one of the most mysterious and little-studied creatures on the planet.

Where to see: waters near the Australian island of Tasmania are one of the few places on the planet where fireflies swim close to the shore. In 2011, Michael Baron filmed an 18-meter sea unicorn in these places.

Green animals

Thanks to a protein isolated from jellyfish, scientists have bred animals that glow green when illuminated with ultraviolet light. In 1998, the first green mouse with the GFP gene appeared, then scientists gave the world green pigs and sheep, glowing multi-colored GloFish fish and genetically modified silkworms that produce fluorescent silk. Scientists hope that colored genes will help fight diseases such as HIV, oncology, Parkinson's and Alzheimer's diseases.

Nature is generous. It gives beauty and grace to some, intelligence and cunning to others, poison and a menacing appearance to others. The unfortunate and ugly, who live in deep darkness, also get something.

Bioluminescence is the ability of living organisms to glow, achieved independently or with the help of symbionts. The name comes from ancient Greek. βίος, "life" and Lat. lumen- "light". Light is created in more highly developed organisms in special luminous organs (for example, in the photophores of fish), in unicellular eukaryotes - in special organelles, and in bacteria - in the cytoplasm. Bioluminescence is based on chemical processes in which the released energy is released in the form of light. Thus, bioluminescence is a special form of chemiluminescence. Wikipedia

1. Hatchetfish Sternoptychidae

The abdomen of this small tropical fish, living at a depth of 200 to 2000 m, is equipped with photophores that produce green radiation. Luminescence masks the silhouette of the hatchet: against the background of backlight from above (from the surface of the ocean), the fish becomes almost invisible to predators living below.

2. Glowing larvae Arachnocampa luminosa

The ceiling of New Zealand's Waitomo Cave resembles a starry sky. This is how the larvae of the local fungus gnat sparkle. They weave silk nests, lower down many threads with sticky liquid and with their shine attract prey - midges, snails and even their own adult relatives.

3. Nochesvetka Noctiluca scintillans

The mysterious glow of the sea, which has been fascinating sailors and fishermen in different places for centuries globe, are caused by single-celled organisms, dinoflagellates, that form aggregations in surface waters. The pulses of light they emit may be an alarm signal.

4.Glowing mushrooms Mycena lux-coeli

Over 70 species of luminescent mushrooms are known. More than 40 of them belong to the genus Mycena. Japanese mycena lux-coeli mushrooms growing on fallen trees are only 1–2 cm in diameter, but their glow can be seen in the dark at a distance of 50 meters. Presumably, this is how the mushrooms attract insects that carry the spores.

5. Hell Vampire Vampyroteuthis infernalis

The cephalopod, the only modern representative of the vampiromorph order, lives at a depth of 400–1000 meters, in the oxygen minimum zone. His entire body is covered with photophores, the activity of which the vampire has good control over: he can control the duration and intensity of the flashes. Instead of ink, in case of danger it emits a cloud of sparkling mucus.

6. Scorpios Scorpiones

A handheld UV lamp has long been used for night field surveys of these animals. Scorpions do not have the ability to bioluminescence, but their exoskeleton contains fluorescent substances that are activated under the influence of ultraviolet waves of a certain length.

7. Fireflies Lampyridae

There are about 2000 species of beetles in this family. They all have luminous organs different types. The most common is the lanterna, located on the terminal segments of the abdomen. Light signals of varying intensity and duration are a means of communication between females and males.

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If we are asked to remember any luminous animal, then most likely we will name the firefly bug. But in fact, he is not the only one who has the ability to glow in the dark. The seas and oceans are especially rich in such inhabitants.

Varieties of sea luminous animals

On the shores of the Black Sea you can often see a breathtaking natural spectacle. On the water surface with small ripples, a strip of light suddenly sparkles, followed by a second, then a third... Who lights these colorful lights?

Scientists have long found out that it’s all about billions of microscopic organisms - ciliates nocturnal flowers, which are found in great abundance in sea ​​waters. Inside each ciliate there are several yellow balls - they are the source of light.

If we dive deeper from the surface of the sea, we will discover even more luminous animals.

1. Jellyfish, spreading out their gelatinous umbrella bodies, can glow different colors: yellow, blue, green and red.
2. There are “fireflies” among fish. Some have glowing eyes, some have a growth growing right on their muzzle that emits light like a light bulb, and the third (an angler fish) has a cord with a luminous end attached to its lower jaw. There are also fish that glow throughout their entire body, thanks to special organs located along it, for example, the hatchet fish.
3. There are luminous sea animals even in the deepest depressions, where not a single ray of light penetrates from the outside. At the very bottom, among the stones you can see glowing shellfish and worms. Their bodies, like diamond dust, are dotted with specks and spots that emit a glow. On the ledges of rocks surrounded by light lie starfish , A deep sea crayfish illuminates his path with huge eyes.
4. IN underwater world can also be found emitting light corals and polyps, for example, a sea feather and a regular sprig of red coral.

Varieties of luminous animals living on land

On land, the ability to glow in the dark is mainly possessed by beetles. Thus, in Europe alone there are six species of them, united in one large family of “lampirids” or fireflies. Fireflies can put on a very colorful spectacle when they cling to some tree or shrub at night.

Why do animals glow?

An example of how some animals produce light is cephalopod . There are small, oval-shaped, hard formations in his skin. Their front transparent part protrudes outward from the skin and works like the lens of the human eye. The back of the formation is located in the thickness of the skin, as if wrapped in a black mantle of pigment cells.

Under this mantle there are several more rows of silvery cells, which are middle part luminous organ of the mollusk. And even lower there are complex cells similar to the nerve endings of the retina of a mammal. It is they that line the entire internal surface of the oval formation (corpuscle) and release light outward, refracted and amplified by the front transparent part.

The light is also doubled thanks to special reflectors in the skin of the mollusk, located next to the oval body. These reflectors are similar in shape to concave mirrors and, in turn, also consist of several layers of light-sensitive cells.

The light design of a cephalopod is the most complex in the animal world. The luminous devices of other creatures are simpler.

Thanks to the study of the depths of the sea, scientists were able to get acquainted with unique deep-sea creatures with phenomenal abilities. These include, for example, angler fish. Life in complete darkness left its mark on them. On the body of these fish there is a process, at the end of which there is a flask filled with bioluminescent bacteria. They just glow.

But, as it turned out, other fish living at great depths can also glow. This effect is called biofluorescence. Among these sea ​​creatures may include: stingray, moray eel, sea ​​needle, fish - stone, fish - surgeon and a number of others. The glow of their bodies has a slightly different nature. It is due to the special structure of their skin. Under the influence of light rays belonging to the blue light spectrum, their bodies begin to glow, acquiring neon, red, yellow, orange and other light shades. Scientists call this phenomenon biofluorescence.

Its main difference from bioluminescence is that there are no chemical reactions that cause the glow. The glow effect, in this case, has a slightly different nature. In this case, the bodies of living organisms absorb blue light rays, transform them into rays of a different spectrum, and emit them into the surrounding space.

Fluorescent molecules located in the skin living beings. It is they who absorb the rays of the blue light spectrum. When light photons collide with these molecules, they are excited, accompanied by the release large quantity energy accumulated by the electrons of fluorescent molecules. They cannot remain in this state for a long time, and will try to get rid of excess energy in order to transition to a normal state. This is what ultimately happens. The energy is released and in the form of light photons goes into the surrounding space, causing a glow, but of a completely different light spectrum. Depending on the energy level of the emitted photons, the body of a living being will acquire different color shades.

It turns out that fish living in the ocean, which have the effect of biofluorescence, absorb light rays of the blue spectrum. A completely logical question arises, why only blue? The thing is that light rays of the red and infrared spectrum are absorbed top layers water, therefore, mainly rays of the blue and green spectra penetrate to depth. Scientists have found that at a depth of more than 100 meters, only blue light rays are present, which are absorbed by the bodies of deep-sea fish.

Ecology

Some living organisms can illuminate dark places without help sunlight. While The most famous bioluminescent creatures are fireflies, besides them there are various types insects, fungi, bacteria, jellyfish and bony fish that can glow. They often use chemical reactions at night, in caves or in the black depths of the ocean.

Bioluminescence has evolved along with life on earth, although there are no flowering plants with this ability and very few animals that can glow, researchers believe that these abilities have evolved independently many times.

As representatives say new exhibition bioluminescence at the American Museum of Natural History in New York, it has evolved at least 50 times, and maybe more. Among bony fish, the ability to glow, sometimes with the help of glowing bacteria, has evolved 20 to 30 times in different groups, according to John Sparks, curator of ichthyology at the museum.

"Even in the case of fish, we know that each time the abilities developed independently of each other, because the process involved different chemical reactions used by different groups. Some used the 'services' of special bacteria, others learned to glow on their own."

Glow-in-the-dark organisms use different variations chemical reactions, which include at least three components: the enzyme luciferase, which helps oxygen bind to organic molecules(third component) is called luciferin. The highly energetic molecule created by the reaction releases energy in the form of light.

According to the exhibition materials, bioluminescence has many applications for organisms that use this component. Fireflies use light to attract mates and warn predators of toxins they might encounter if they attack the fireflies. Deep sea anglerfish use “lit” bait to attract prey. The belly of silver belly fish also glows, which is a kind of camouflage that helps them fit in environment. Dinoflagellates - the simplest single-celled organisms - begin to glow if they are disturbed, perhaps they do this in order to scare off a predator, or to attract another predator that feeds on their “enemy”. Mosquito fungus larvae glow to attract prey.

Most bioluminescent organisms, about 80 percent of species, live in the most "densely populated" place on the planet - deep in the sea. In fact, it is believed that most species that live below 700 meters can produce their own light. There is no consensus as to why the ability to glow has evolved so many times, but the theory is an adaptation to life in sea ​​depths, according to Sparks, the most popular.

"Luciferins, these light-producing molecules, are good antioxidants, so it's thought that they may have been antioxidants for a period of time and then retrained," Sparks explains.

As oxygen levels in the ocean increased, animals moved into deeper waters to stay out of reach ultraviolet radiation. IN deep waters, where antioxidants are no longer needed to repair genetic damage caused by UV radiation, luciferins have evolved into organisms that produce light.

However, not everything that glows is bioluminescent. Some organisms, such as corals, glow by absorbing light at one wavelength of ultraviolet radiation and releasing it at another wavelength. Since UV radiation is not visible to the human eye, these creatures may appear to produce their own light.

The exhibition "Beings of Light: Natural Bioluminescence" opens in American Museum Natural History in New York on March 31 and runs until January 6, 2013.