Dragonfly description for children. Dragonfly brief information

It's no secret that dinosaurs lived on our planet 235 million years ago. For a long time, these animals were the true masters of the Earth. In addition, some of them differed in unimaginable, simply gigantic size, so the finds of archaeologists still do not cease to amaze our imagination.

We present to your attention the most amazing giants that have ever inhabited our world.

Sarcosuchus

A genus of giant crocodilomorphs that lived on the territory of modern Africa at the beginning of the Cretaceous period. Sarcosuchus reached 12 m in length, and its mass reached 8 tons. This is one of the largest giant crocodile-like reptiles that have ever lived on Earth.

Titanoboa

A species of extinct snake that lived on the territory of modern Colombia about 60 million years ago.
Titanoboa reached 13 meters in length and weighed more than a ton. The predator did not have poison, so she simply choked and swallowed her prey.

Syrian camel

The growth of this animal reached 4 meters. This giant lived in Syria about 100 thousand years ago. The remains of the animal were first discovered in 2005. According to scientists, ancient people actively hunted the camel, which could lead to the extinction of the species.

Mosasaurus

Mosasaurs reached a length of more than 17 m, and also differed in massive teeth adapted to crushing bones and tearing flesh. big booty. These marine animals ate their own kind and plesiosaurs.

Liopleurodon

Another type of marine reptile jurassic. Liopleurodon reached 25 m in length and weighed about 100 tons. The predator fed on large fish, mollusks, and from time to time attacked other marine reptiles.

Indricotherium

The tallest and heaviest ever land mammals: their height was about 5 m, and their weight reached 20 tons. These animals from the hyracodont family lived 30-20 million years ago in the middle Oligocene - lower Miocene. They ate leaves and shrubs, inhabited the territory of modern Asia.

Kronosaurus

One of the largest pliosaurs of the Early Cretaceous. It reached about 10 m in length, and weighed 18 tons. The name was given in honor of the titan Kron from ancient Greek mythology.

Megalodon

One of the largest predatory fish of all time. Megalodon existed in the Miocene and Pliocene, and on average reached a length of about 15 m, and weighed up to 47 tons.

Leedsichthys

Giant extinct bone fish Jurassic period. The length of Leedsichthys was about 30 m, and the weight was 19 tons. Like the whale shark, it fed on plankton.

Shastasaurus

A genus of ichthyosaurs from the Middle and Late Triassic. largest marine reptile ever discovered. The length was 20 m, weight - 35 tons. Presumably, the shastasaurs fed on mollusks.

Asian straight-tusked elephant

The largest representative of the proboscis, whose height reached 5 m, and weight - 22 tons, lived in the Pleistocene in the territory from India to Japan.

Spinosaurus

Incredibly large carnivorous dinosaur that lived on the territory of modern North Africa in Cretaceous. Spinosaurus was huge: about 18 m long and weighing up to 20 tons. The animal was able to swim, and its main food was fish.

Argentinosaurus

Also one of the largest animals in the history of the world. So far, only fragments of its skeleton have been found, so length estimates range from 22 to 35 m, and weights from 60 to 108 tons. The growth process took 40 years, the Argentinosaurus consumed 100 thousand calories daily.

Whale shark

The largest of the currently existing species of sharks, as well as the largest of all modern fish. Reaches 11 m in length and weighs approximately 18 tons, but this is not the limit. Feeds on plankton.

Blue whale

The largest modern animal, probably the largest of all animals that have ever lived on Earth. Its length reaches 33 m, and its weight can exceed 150 tons. The length of a newborn blue whale is 6-8 meters, it receives up to 90 liters of milk daily. Intensive fishing has led to a significant reduction in the number of these animals.

Dragonflies are called "air pirates of the insect world". These are voracious and dexterous hunters. Dragonflies catch their prey in the air and often eat it without interrupting the flight.

   Basic data:

   Depending on the structure of the body, two groups can be distinguished: large and fast representatives of the suborder Anisoptera (unequal-winged dragonflies) and smaller, gentle and slow-moving damselfly dragonflies (series Zygoptera). On the head of a dragonfly, large jaws and huge eyes are visible, each of which consists of about 25-30 thousand simple eyes. In uneven-winged dragonflies, the eyes occupy most of the surface of the head, they converge at the top and allow insects to see almost everything around.
   The eyes of homoptera dragonflies are smaller and far from each other, so the shape of their head resembles a hammer. They see homoptera dragonflies as well as their mentioned relatives. Some dragonflies can turn their heads to change their viewing angle. The antennae of dragonflies are small and inconspicuous. The body of a dragonfly differs from the body of other groups of insects. It is slanted, so the lower part, from which the legs grow, is pushed forward, and the upper part with wings is pushed back.
   The first pair of wings grows out of the body higher than the second, and the first two pairs of legs are immediately behind the head. Such an arrangement of the legs does not allow dragonflies to walk, however, due to this body structure, they can hold their feet on any base and successfully catch prey with them.

  

DO YOU KNOW WHAT...

• Of the 4700 species of dragonflies in Europe, less than 100 can be found.
• The larvae of large dragonflies escape from enemies in a special way - they push water out of the rear opening with force, and therefore the larva can rapidly move forward with a quick push, like a jet engine.
• Dragonflies were one of the first forms of flying insects on our planet. They appeared over 300,000,000 years ago. Fossils give us evidence that the wingspan of ancient dragonflies reached ninety centimeters.
• If a male dragonfly decides to mate with a newly fertilized female, he removes the sperm of the previous partner with the help of a special organ and fertilizes the female again.

   The ancestors of modern dragonflies, which had a wingspan of up to ninety centimeters and a body length of up to thirty centimeters, already existed in the Carboniferous period. All dragonflies have the same body structure and a similar lifestyle. Scientists distinguish two suborders - small equal-winged and large uneven-winged dragonflies.

BREEDING

   When a young dragonfly first rises into the air, it still looks rather modest, as if its metamorphosis has not been completed. Only after a few days or even weeks does it acquire the color of an adult. At this time, dragonflies stay away from the water and return to it only with the onset of the mating season. The males arrive first. Males of almost all dragonflies are colored much brighter than females. Males of some species fight each other for territory. The winner sits on a place located on a hill, and from there attacks any male who dares to cross the boundaries of his site. When a male notices a female, he seeks to win her favor and prevent mating with other males. The secondary genital organs of the male are located on a specific protrusion of the third segment of the abdomen. In a special hole located on the abdomen, the male lays the spermatophore. Then he grabs the female by the neck with his pincer-like appendages of the posterior end of the abdomen and drags her along in the air until she raises the posterior end of the abdomen to the spermatophore. Dragonflies flying in pairs look like a ring. In this position, the partners remain for an hour or even longer. A fertilized female lays her eggs either directly into the water, or into the underwater or surface parts of plants. The uneven-winged dragonflies usually lay their eggs directly on the water, while the equal-winged dragonflies carefully place them on plants.

LIFE CYCLE

   In temperate climates, dragonflies appear in the spring and die late autumn. Only some species live longer than a few months. But the winged individual is the last stage of the complex life cycle which may last for several years.
   In autumn, before dying, the female dragonfly lays her eggs on aquatic plants growing on a swampy shore or in the water. In the spring, embryonic larvae with an elongated body hatch from them. They immediately molt and turn into naiads with well-developed limbs.
   Naiads have no wings, they are modestly colored and live in water. Their body consists of a head, often with large eyes, a chest with two pairs of legs, and an abdomen with respiratory organs. The respiration of dragonfly larvae is carried out due to oxygen dissolved in water.
   In larvae of homoptera dragonflies, the respiratory organs are leaf-shaped tracheal gills located at the posterior end of the abdomen. Naiads are the same predators as adult dragonflies. They grow rapidly and molt 9 to 15 times during development. Under water, naiads, before turning into adults, can develop up to 6 years.

HUNTING

   Dragonflies are well adapted to hunting flying insects in the air. In doing so, they use two main methods: uneven-winged dragonflies usually examine the territory from the air, and equal-winged dragonflies (buttercups, beauties and arrows) usually lie in wait for prey, sitting in ambush, and when it approaches, they rush at it. Most dragonflies fly during the hottest hours during the day. Especially a lot of them along the banks of reservoirs. When hunting, dragonflies rely only on sight - the sense of smell does not help them in hunting. The large compound eyes of these insects catch any, even barely noticeable movement. When potential prey approaches, and tracking shifts from one simple eye to another. The dragonfly moves its head in such a way as to make the image as clear as possible, and thus decides whether it can overcome the prey.
   Excellent vision is combined with unique abilities to fly. The dragonfly's muscles are arranged in a special way. Although physiologically it has four wings, each pair of wings works so well that in fact there are only two wings. Due to this, the dragonfly can hover in flight, move to the side and even back away. Sometimes dragonflies can reach flight speeds of up to 30 km/h.
   So, from a favorable position in the air, dragonflies rush to prey with their legs apart, with which they, like a basket, capture the victim. Caught prey, they begin to eat in flight.
   If the naiad sees the prey, then she grabs it, throwing forward the "hand", at the end of which there are sharp jaws. Folding the "hand", she pulls the prey to the mouth.

The message about the dragonfly, a six-legged arthropod, will tell you about its full characteristics.

Dragonfly Report

General information about dragonflies

Dragonflies are hard to confuse with other insects. They have a bright and shiny color, a large head and powerful wings. The head of the insect is movably connected to the chest. This gives him the ability to rotate 180 0 around its axis.

The eyes of a dragonfly occupy most of the head and consist of 30,000 small facets - small eyes. They work independently of each other. Top part facets recognizes shapes, and lower colors of objects. The dragonfly is able to detect prey at a distance of up to 8 m.

The mouth of the insect is armed with jaws and not in vain, because they are voracious predators. The chest consists of an anterior thorax with one pair of limbs and a hind thorax with legs.

They have 2 pairs of wings, which can be either the same or different in size. Wingspan up to 18 cm.

How long do dragonflies live?

The average lifespan of an insect is 10 months. Many species die after 6 weeks. But centenarians can wait out adverse conditions in shelters.

What types of dragonflies exist?

Scientists today have described more than 6,000 species of dragonflies. We suggest viewing only the most common species.

Dragonfly species:

• Dragonfly Vigilant Emperor
• Dragonfly Cordulegaster Ringed
• Dragonfly grandma metal
• Dragonfly Dedka ordinary
• dragonfly
• dragonfly beauty girl
• Dragonfly South Arrow
• Dragonfly Lyutka Dryad
• Dragonfly Megaloprepus caerulatus (largest in the world)

Where do dragonflies live?

They can be found anywhere in the world where warm weather, eat plenty of water and food. The habitat of dragonflies is Russia and Belarus, Germany and France, Italy and Spain, the countries of the Balkan Peninsula. Some species of dragonflies are found in Pakistan and India, Azerbaijan and Thailand, Iran and Armenia, China and Turkey.

What do dragonflies eat?

Dragonflies are typical predators that catch their prey on the fly. The main food of insects is mosquitoes, flies, moths. Large representatives can eat spiders of small fish, frogs.

Dragonflies interesting facts

• Dragonflies can live underwater for two years. And in the state of the larvae even six years.
• Before getting the beautiful color we are used to seeing, dragonflies molt about 17 times.
• In 2009, the world's first dragonfly sanctuary, the Dragonfly Center, appeared. In it, scientists managed to raise the number of 42 species of these insects inhabiting the UK.
• The eyes of a dragonfly cover the territory in its field of view by 360 °.
• The dragonfly is completely deaf by nature.
• She can turn her head in any direction.

We hope that the above information about the dragonfly has helped you. And your short story about the dragonfly, you can leave through the comment form.

The history of the appearance of dragonflies in the world dates back more than 300 million years ago, when there were not even dinosaurs yet.

Ancient insects were huge in comparison with dragonflies in modern world, their wingspan reached one hundred centimeters.

Translated from English, "Dragonfly" means "flying dragon", and translated from Latin "Liberalla" - small scales.

Many works in folklore are dedicated to the dragonfly, and the dragonfly amulet made of gold seems to be a talisman that brings success.

Dragonfly structure

The dragonfly has an amazing eye structure that allows you to see danger from all sides at a distance of 10 meters. Two big eyes located on the head, look disproportionately with the body.

But in fact, on both sides of the dragonfly's head there are not two, but several dozen small eyes that work autonomously from each other and are separated by pigment cells.

The body of a dragonfly contains a head, a thoracic part and an elongated body, the limb of which consists of two special tweezers. The wings are reinforced with transverse and longitudinal veins. In the modern world, dragonflies are found in different shades and reach from 3 to 14 cm in length.

Basically, dragonflies move in the air at a speed of 5-10 km / h, but in some categories of these insects, the flight speed reaches 100 km / h. They hunt for prey of dragonflies with the help of six tenacious paws covered with protective bristles.

It is noteworthy that when developing aircraft designs, engineers adopted distinctive features structures of the wings of dragonflies.

In the photo of the dragonfly below, you can see that there are dark spots on the wings. They help the insect overcome the vibration of the air.

Dragonfly life

Dragonflies live on lawns, fields, near water bodies in different countries with a temperate climate. Insects lead an active lifestyle, flying over considerable distances.

When landing, a dragonfly always spreads its wings, unlike many insects. Insects prefer to hunt alone during the day.

The dragonfly silently sneaks up on the victim and captures it, folding its legs into a "basket". These arthropods easily dodge dangerous predators in the air, due to the special structure of the eyes and considerable flight speed.

Categories of dragonflies

There are about 5,000 dragonfly species. There are dragonflies of different-winged, homo-winged species.

Another separate group, called Anisoptera, contains features of both groups.

Representatives of homoptera dragonflies include beauties, arrows, and hatches. They are light in weight and have wings with the same size.

Different-winged include types of dragonflies: ortetrum, libellulus, sympetrum, yoke. In this group of insects, the hindwings expand towards the base.

Pretty girls dwell in southern regions with a subtropical climate. This subspecies of dragonflies lays its eggs in water bodies at a depth of 1 meter. They prefer to settle only near clean water.

By the location of the beauties, you can determine the degree of pollution of reservoirs.

A rare species is Fatima, which lives in mountainous areas. This specimen of dragonflies is listed in the Red Book.

Dedka ordinary is located in Europe, in the Urals and near the Caspian Sea.

The ant lion, like the king of beasts, leads a leisurely, lazy life.

How does a dragonfly eat?

The dragonfly preys on small insects in the air with its serrated jaws. The dragonfly waits for a large prey on the ground, when the prey approaches, it clings to it with its paws and quickly eats it.

The dragonfly is unusually gluttonous, every day she has to catch prey for food that is much larger than her own weight.

For one day, a dragonfly will need about a hundred different insects to eat.

Reproduction and lifespan

Before the mating of dragonflies, a real ritual takes place. The male masterfully dances the mating dance to attract the attention of the female to his individual.

After the insect still achieves the location of its attracting object, mating takes place right in the air. From laying eggs to the appearance of a full-fledged insect, a large amount of time passes into the world.

The development interval can be up to 5 years. The dragonfly lays more than 200 eggs in one clutch, therefore, despite the long formation of the embryo, dragonflies are not considered an endangered species.

In addition, the larvae themselves can prey on small tadpoles, but often become food for fish.

Dragonflies live for about 7 years, considering all stages of development from the larva. An adult can last about 1 month in an independent habitat of wild animals and plants.

There are rare cases of courting a dragonfly at home. Although this is rather an exception, usually insects live only in the wild.

Dragonfly photo

Our topic today is an insect, which in its shape is a bit like a helicopter - a dragonfly. Pay attention to its English name - dragonfly, which means "flying dragon"(learn about dragons). As you know, predatory animals are those that feed on other animals. All groups of animals have their predators. For example, tigers attack other mammals on earth, sharks are formidable masters of the water element, near the water and on the shore - of course. There are also many predators in the world of insects, but we will talk about the most unusual and terrible.

If someone asks you without hesitation to list all your favorite or just liked insects, you can do it quite easily. If you are not an entomologist, then the answer will be standard: butterflies, dragonflies, ladybugs and other cute insects that will not crawl under the skin of a person when he sleeps. However, let the dragonfly grow at least half a meter long, as it suddenly turns out that it is not so cute and harmless. In fact, if the Meganeuri, or giant dragonflies, had not died out, they could have replaced humans on the planet. And all because of the fact that dragonflies in the world of insects are the most successful killers. For example…

The perfect murder in the animal world is not a movie, but a reality!

Fact #5: To get the perfect kill, dragonflies calculate their speed.

The dynamics of prey capture in the air is so complex, as if it is produced not by an insect, but by an animal with a complex nervous system, such as a seagull or even a person. Going to intercept, the dragonfly moves at its own speed, but it is very difficult to predict where it will end up in the end. When researchers began studying dragonflies in 1999, they found that instead of simply following their prey through the air until they catch up, the dragonflies intercept it. In other words, they are like identify possible routes of her prey, appearing where she is least expected. This means that dragonflies can calculate 3 things while hunting: the distance to the prey, the direction of its movement and the speed of flight. In a split second, the dragonfly calculates the angle of approach and waits for the unfortunate fly to fall right into the "claws".

Developed vision in tiny insect predators is normal.

Fact #4: Dragonfly eyes are incredibly large.

Most insects have multifaceted eyes, for example, the organ of vision of some representatives contains about 6000 elements, which give them a panoramic view of their surroundings. This is the reason why their eyes see very close. A dragonfly has 30,000 individual faces. Each face, or ommatidium, creates its own image, and the dragonfly's brain, using visual neurons, summarizes thousands of images into one picture.

The structure of the eye of a dragonfly it is such that with its upper eyes it can only distinguish monochrome colors - white and black. Therefore, when she sees the victim, she follows the black dot on the light background of the sky. But in its famous interception maneuver, the dragonfly rises above its prey and needs to have a good view of it. At this point, the lower eyes, which distinguish colors, are included in the work.

The unusual properties of the eyes allow dragonflies to see the victim at a distance of up to 8 meters. The dragonfly sees everything that happens around it, from the side, in front and even behind. Among insects, her eyesight is the best.

Panoramic view - the highest quality view of the available space.

Fact #3: Dragonflies can see in all directions

The massive bulbous eyes of the dragonfly, wrapped around its head like a helmet, allow for a 360-degree view of what is happening. As dragonfly researcher Dr. R. Olberg put it: “They can see you when they fly towards you, and they can see you when they fly away.” Obviously, this is a valuable tool for hunting. A dragonfly can escape from an attack from behind, while for many insects it would be fatal: this zone is inaccessible to their vision. Dragonflies take advantage of their vision: when hunting, they attack from behind and from below - from where the victim cannot see them. Dragonflies do not have dark spots in their vision (the "blind spot" in CCTV cameras), so they are impossible to catch.

Before proceeding to the next fact, one more circumstance should be noted. When dragonflies hunt, their eyes allow them to use their vision like a grid. Prey management in some form helps dragonflies hunt with incredible accuracy, intercepting the victim in flight.

For a better understanding of the mechanism of work, such an example is suitable. On the windshield car, you need to draw a grid and select a target, for example, it will be a goat. The car should be directed so that the goat gets into one of the squares. Now you should approach the goal, keeping it in the same square. In this case, the distance is reduced, but the angle of movement does not change, even if the target is moving. After a while there will be a collision. (Please do not repeat this experiment. This is just a theoretical example).

Efficiency is, for example, efficiency - efficiency in catching prey.

Fact #2: Dragonflies are effective hunters

Dragonflies are incredibly efficient, 95% of the time they capture their prey. In comparison, sharks, one of the most ferocious predators in nature, manage to catch only half of the prey they hunt. Lions - "sharks on the ground", are more fortunate - they hit more than half of their targets. At the same time, lions move along the savannah in zigzags following the prey, without thinking through the trajectory of its movement. If dragonflies were so big that they could prey on gazelles, then lions would starve to death because they would be clearly inefficient.

When a dragonfly sees its prey, it almost always catches it.

Multitasking is not only Operating Systems but also insects.

Fact #1: Dragonflies can isolate their prey when they are among their own kind.

In this insect, vision and processing of the information received has another amazing property. During the experiments, scientists discovered exactly how the dragonfly chooses its prey. In an effort to learn as much as possible about the hunting of dragonflies, they implanted a nano-electrode into the neuron, which produced an image on the screen.

In simple nervous systems, which most insects have, several objects disappear from view because the insect's attention does not work in multitasking mode. However, dragonflies can switch from one object to another at will. The dragonfly, which was implanted with a nano-electrode, first focused on one object, and then switched to another, and then returned to the first without losing sight of anything. This selective concentration of attention allows dragonflies to focus on a single target while still being aware of the rest of the swarm, avoiding collision, and choosing their prey "to their taste".

Adapted from an article by Andrew Handley.