The world lives a huge number of amazing creatures. Some dwell in the sky, others on earth, and the third and prefer the water at all. However, there are those who skillfully combine at the same time all three elements. Watercase. And it is about her that will be discussed in our article.
Insect Watercase: Why was the little bug called?
"Watercase" - the name of the beetle, habitual for russian-speaking countries. Our ancestors came up with this name, looking at how the insect slides on the water. They got the impression that it seems to measure water. In this case, this name was so attached to the beetle that even today it is still cleaned. Although B. english language His name sounds like Water Strider, which means "running around the water."
General information about the form
It should be noted that this is a very common insect. The water meter dwells almost everywhere, with the exception of the cold lands of the Arctic and Antarctic. Scientists consider these creatures to the family of semi-rigid insects, the bugs suburbs. To date, more than 700 species of water meters are known, which differ not only appearance and sizes, but also familiar to life for them.
Appearance and distinctive features
So, what does the water member look like? Insect, whose photo is more like a floating wand, has a rather long, elongated body. Depending on the subspecies, its size can range from 1-2 cm to 4-5 mm. At the same time, the most tiny is the insect inhabiting in maritime expanses.
The main feature of any water member long legs. Often their size exceeds the body of the cloud. Such proportions are associated with the fact that the paws are the key to the survival of the species. After all, they allow the insect to quickly slide on everything from the water member of six limbs. It also has wings, but they use it quite rarely.
Most of the representatives of this species are painted in dull tone. The most common are brown and black colors. By the way, such a color is not accidental - nature has specially awarded them insect. The water meter is almost always in the open space, because dark tones, perfectly merging with water, is its only chance to protect against constantly hungry birds and amphibians.
Ability to run around the waves
Watercase - insect, the description of which is always reduced to the story of his amazing ability to resist the water element. So how does she manage not to sink? The thing is that the clusters are covered with a special substance, by their structure resembling fat. It creates a certain similarity of a barrier that does not give limbs to immerse yourself in water.
In addition, the insect knows how to properly distribute the weight: the load falls on one point, and it is evenly transferred to all six extremities. As for the high speed of movement, it is achieved at the expense of fast, pulsed rigs. It is they who create behind the waters of the twist, which pushing it forward.
It is noteworthy that the bug can float both on mirror-smooth surfaces and among the waves. It is this skill that allows the water meters to settle on various types of water bodies, which significantly increases their survival, and in effect, and the population.
Ration
Do not think that this is a peaceful insect, the water member is a real predator. She boldly attacks any small creature, which was not lucky to find out on the surface of the water. Such arrogance is quite acquitted, as other insects are not able to give her back, being in an alien to the elements.
The principle of hunting by water meters is very simple. As soon as the extraction falls into the water, they lightningly swim in it and cling to the body with hook-shaped front legs. The predator is then breaking through the sacrifice sheet using an acute trunk located on the head. After the water meter, it remains only to suck the liquid from the body of an unfortunate being.
Features of behavior of water meters
Many mistakenly suggest that this is an extremely water insect. Watercase is really spending most of his life in the pond, but this does not mean that it is not able to conquer other elements. For example, she has wings that allow minor flights. She enjoys them in the event that its native reservoir begins to disperse and she needs to find a new refuge.
Also, these bugs can crawl on the ground. They do it very ineptly, since thin paws are constantly stuck in small cracks and faults. However, despite this, drying is vital for them. The thing is that the water meters cannot winter in water, and therefore is looking for a warm house in the ground or on a tree. Thus, this is really unique, because he managed to conquer three elements at once.
Natural enemies
The main enemies of the water meters are birds and amphibians. The first insects in the insects in quiet sunny weather, and the second skillfully track them at the edge of the coast. Naturally, they cannot cause much harm to the population, but single individuals clearly have to come to humble with sad fate.
In our current list - amazing representatives of the animal world, which can move around the water:
1. Lizard Vasilisk (Basilisk Lizard)
Vasilisk lizard, also known as a lizard Jesus Christ, hides from predators falling from the top of the tree and running along the surface of a water body located under the tree. They can run about 4.5 meters, developing an impressive speed of one and a half meters per second.
Long fingers on the hind legs of these lizards are interconnected, so quickly slamming with its rear legs on the water they create air pockets that do not let them go under the water, if only they retain their speed. When they still go under the water, they can swim. Nevertheless, they prefer to run through water to avoid the risk of being eaten water inhabitants.
2. Brazilian Dwarf gecko (Brazilian Pygmy Geckos)
This tiny is not just charming, she is also talented. Due to its low weight and water-repellent skin, hekcon can be easily walking on the surface of the water. Since hekcon is so tiny (they are smaller in size than many of insects living in tropical forests Amazon), he risks drown even in the smallest pool - scientists believe that it is why their ability to walk on water developed.
3. Water meters 
Watercases belong to the family of water meters, characterized by their ability to walk on water. They can do this due to water-repellent legs that help increase the water surface voltage equally distributing the weight of the insect body to all its paws. Their movements also help them move around the water. They repel the middle pair of the feet, making circular movements, similar to the movement of the movement, and slide forward on the water.
4. Spiders Hunters (Fishing Spiders)
Spiders-hunters, also known as Dolomedes, are semi-water insects living near the reservoirs where they hunt. They are waiting on the shore by the reservoir until the ripples will notice on the water and then run along the water to catch prey. Water also helps them to avoid predators, as they can hide right below the surface, enveloping their body with tiny bubbles. Although most spiders hunters feed on insects, more large species Can also eat small fish, tadpoles and frogs.
Like Gecko, spiders-hunters can move through water due to their small weight and abundance of short water-repellent hairs on the body. Sometimes they float on the water, putting several paws upstairs to the wind of them in the right direction. Their short hairs also allow bubbles to form around their bodies when they are hiding under the surface of the water. In fact, they are so floating that they have to grasp something, being under water, otherwise the water will push them to the surface, and completely dry. Some types of hunters can be under water for half an hour.
5. Dolphins
Given that they have no legs, it is difficult to say that the dolphins "go" water, but they are famous for their ability to dance over the waves with the help of their tail fins. Unlike other animals that use their ability to walk on water as any evolutionary advantage, dolphins, according to scientists, do it purely for fun - for them this is equivalent to human dances.
It is interesting that, although the dolphins can "walk" with the help of a tail, they almost never do it in wildlife. Exceptions are cases when Dolphin nailed to the group of wild dolphins, which was previously in captivity and was trained.
6. West American Clark and Clark (Western and Clark "S Grebes)
Like the West American toadstool, and the Clark's clariner possess a unique and beautiful ritual of the marriage games called "Spext", during which a couple of birds runs through water. Birds rush forward with all body and become paws on the water, simultaneously flapping with wings. Then, the pair runs through the water in unison at about 9 meters, making 22 impacts on the water in a second.
These birds spend almost all their lives in the water. They have short wings and strong legs that are not very convenient for walking on land, but indispensable for the marriage ritual.
7. Kachrka
Unlike other animals in this list, this bird does not walk along the surface of the water, although it is the impression that is created. In fact, it ferry near the surface of the water and lowers the paws in her, grabbing prey. Paws of birds are too weak to maintain its weight for more than a few steps. Because of this, it seems that she can walk longer on the water than on land.
8. Heron on Hippopotam
Herons really can't walk on the water, however, the bird looks like this video that it turns out that it turns out - until the hippopotam appears above the water surface, showing us what the secret of the heron actually lies. She, she can't walk on the water, but it came to it so close as possible.
I want to continue it a little, i.e. Not only about the water member, about how she runs through water, but also about who from the inhabitants of wildlife can also walk along the water and why. Experiments helped me to conduct Denis Zelenov, 10 years old. Wildlife physics - Interesting perspective.
What helps the dickery to stay on the surface of the water?
You can say about dike with confidence that even if he wants, it will not be able to drown, since the cavities inside its numerous needles are filled with air. It helps the animal to stay on the water surface.
As you can see from the experience: a green rubber ball is not inflated sinking, and a pink ball filled with air - floats. Just like a dike. This, of course, can not be called walking on the water, rather - swimming.
What helps birds stay afloat?
We have seen many times on the lakes, how swans swim, ducks. They are easily held afloat.
This is because their feathers are hollow, and they are very tightly adjacent to each other, creating an air layer. Also, bird feathers have lubricant protecting them from wetting. Their body produces fat. With the help of the beak, the bird constantly lubricates its firm firm, which repels water. Water can not wet feathers, which helps the bird keep warm and stay on the water.
It is easy to check the next experience: we take two threads of akin and one of them perch in vegetable oil. Then put them in glasses with water and we will see that the washed filament of the tank floats, and the second - drowned.
And still waterfowl "run" on the water when taken. So they manage to develop a greater speed. Quickly turning over the paws, and at the same time working wings, accelerate until the speed is rapid for separation. Then, it turns out of all the might from the surface of the water and take off. It resembles an airplane during takeoff.
What keeps the beetle with a water meadow?
The water meter feels very freely on the surface of the water, while remaining afloat. She has paws covered with thousands of tiny hair, which are not wounded.
If you look closely, you can see that where its thin long legs come into contact with the surface of the water, small dents appear on the water. The surface of the water behaves as if it was covered with a thin rubber film, which is stretched under the weight of the beetle, but does not break. Water corresponds to the pressure addressed from the inside to the outside, trying to restore its smooth surface. This phenomenon is called the surface tension of water. It can be observed on a spoon with water filled to the edges - water on a spoon as it were, "hill", which is clearly seen from the experience. A drop of water in flight state, in weightlessness retains the shape of the ball only due to the strength of the surface tension. It is also called the "skin" of water.
The presence of force on the surface of the water we can observe the following experience: We will launch a metal sewing needle or stationery clip. They, like a water member, will be held on its surface.
These experiments show that the water tension of water helps to resist water. The weight of the insect is equalized by surface tension, the force of which exceeds the body weight of the water meter. Thanks to this, the water member remains afloat and can perform jumping up into the air like a person jumping on a trampoline. Thus, the water meters have like two types of gait: jump up into the air and glide on the water. Many of us observed how deftly bug water meters slide on the water! The speed of their movement up to 100 km / h. How do they get them? Scientists have proven that the water meters use their limbs, as if oars. Only they do not immerse their "oars" into the water. Spaces are formed on the surface of the water. These pits work, as if the blade of the oars. Each rowing creates a minibar, twist in water behind the paws. Thanks to this, the water meter and moves forward, as if repulsted from the rear "wall of the deepening", as shown in the figure.
Simplified model paw water meter
How does Vasilisk lizard run on the water?
Slobus Vasilisk lives in Central America. It weighs about 100 grams. Vasilisk is the rarest creature that runs on water at a speed of up to 12 km / h, i.e. Twice faster than a person. Hold on the water and run on it lizard help frequent beats with legs. At the same time in water there are pits with walls. These walls, with fast-repetitive blows, in a short period of time between two adjacent blows behave like solid. When the lizard pushes the water to the foot down and back, then the water responds with the same force, pushing it up and forth. Stripping, the lizard runs on the water as a hare.
How does the fisherman spider go?
The most skilled gardener is a pisaurid, a spider of fisherman. It can slide on the water, as it makes a water member. Can get up in the water to the rear legs and run like a lizard Vasilisk! But most fast way The movement of the spider is movement under the sail. When the wind blows, the spider is waving the front legs, or dresses the whole body and allows the wind to drag it on water like a sailing boat. Even the light impetus can carry it through the whole pond.
As it turned out, very few creatures are capable of walking on water.
Interesting was the day. Today you learned how physics is in nature. I hope you were interested. And if you liked a fun science, then take a gift from me.Collection fascinating experiments, experiments and focus with water.
Nobody can repeat the wonderful walking in the water, well, except for some representatives of the animal world ... What are the forces to help them?
Perhaps the most famous runner in water is klop-water member. Almost all life, the water meters slide over the surface of the reservoirs in search of mining, only for the winter they are moved to land and hide in MCU or under the crust of the old stump. But what's the secret of the runners? First, thanks to a small weight and size. Secondly, the entire body of the insect is covered with water-repellent fats that do not allow the water to get wet. And in the third, Klopu helps to keep on the empty of the thick cover, especially at the tips of the paws, which have direct contact with water, - on one square millimeter can grow up to 16 thousand hair lines. Fur cover over time wets, and if it is not possible to relete it and do not dry - the bug will immediately go to the bottom.
Perfectly feels on the surface of the water beetle-version. The rear paws of the beetle were transformed into the blades to increase the speed of running and steep maneuvering. Especially in the period of mating, the fifty performs complex pyruets and frills - males, gaining speed, make a sharp turn under sharp angle And slowly, like roys on a steep wheelbarrow, swim past the female, the latter in response is prescribed curls and spirals.
Fisherman spiders have similar technique. A huge amount of vague on an insect body, covered with a fatty water-repellent layer, and a very small weight allow spiders to easily slide on the surface of the water. Like watering, spiders hold on to the surface on three legs and a pair of feet serves as "oars".
Run on water can and more large representatives Animal World As Lizards, Birds and Dolphins.
Vasiliski Live off the coast of the reservoirs, hiding in the bushes and in the trees, but in case of danger, he resorts to his amazing ability - run through water. It holds on the surface of the water due to frequent and short slaps. Contact with water lasts only 0.068 seconds. With each zamach, the membrane is captured with a small amount of air, forming a special pillow, due to which the paw does not wet. For this wonderful ability of Vasiliskov called the "Lizards of Jesus Christ".
Birds are easier to run on water than lizards, because the wings create a lifting crave, and it also helps the rapid movement by wide legs. Very often, the water take-off stripes choose those birds that are slow and clumsily moved along the ground.
Birds of the leafing, arrangement of marriages on the reservoirs, run on the water differently than Vasiliski.
We are not surprised when we see a water glowing on the water - it seems to us that the easy insect can be easily held on the sinking of the surface (although it is worth adding that the point is not only in the insignificant weight of the water meters, but also in special hairs covering their body and leg tips) . But when the water begins to run, for example, a large waterfowl, it already seems strange.
West American Miker (photo Mike Forsman / Flickr.com.)
Western American leaning in the marriage race. (Photo Paul Souders / Corbis.)
Clark clariny with cub. (Photo Ron Wolf / Flickr.com.)
Vasilisk, Running water. (Photo Bence Mate / Visuals Unlimited / Corbis.)
Rogging on the water is engaged in the water, and they do not help themselves wings. In addition to the refining, such a trick is able to perform Vasilisk lizards. From the point of view of physics, nothing impossible here, and many, perhaps, will recall the famous task of P.L. Kapitsa: "What speed man should run on the water so as not to drown?" Curious readers can find her decision on the Internet, we will only point out that in the formulation itself some tip lies: the speed of running, obviously, should be large. Indeed, if you look at the running tower, they move the paws very quickly, making at least 20 steps per second. But the secret of "walking on water" is not exhausted only.
Zoologs from Harvard, who watched Clark and West American toadstool in their natural environment, made more than a hundred video starting birds, but just two videos allowed to build a three-dimensional model of the movements of bird paws. Of course, the trafficking (and the lizards of Vasilisk) the paws are still immersed in the water, so that they make partly a step, partly beats. But both movements - that is, the immersion of the paws into the water and pulling it out of the water - birds are doing otherwise than lizards. Paws with floatful fingers are put on the water, spend them under water, and then compress their fingers and pull out the paw on the surface, pushing it away. Compressed in the "fist" fingers and movement of the lobble allows you to reduce water resistance.
Such a propeller movement is unlikely to make Vasili, which move the paws in the same plane, without rejecting them to the side and without squeezing the fingers. In Article B. The authors write that the structure of the paw and the frequency with which they are moving, provide tolers up to 30-55% of the lifting force necessary to keep birds "walking". But the remaining percentages ensures that the characteristic manner moves the paws back and sob. Portal Science. telling briefly about the study mentions another work, also published in THE JOURNAL OF EXPERIMENTAL BIOLOGYBut in 2001 - it said that a peculiar manner of moving the paws makes the referee also with outstanding divers. It is possible that birds will be able to suggest the engineers some ideas as to how our swimming machines can be improved.
But we have not yet told anything about what the birds are engaged in the "surface" run. There are no big surprises here: it is believed that the cerebrals in such races choose a partner that it is simply a marriage dance. A properly run precedes the floating and exchanging greetings, which last a few seconds, the junction itself will also last long, about 7 seconds. Moreover, in artificial conditions, such behavior is almost unable to see, perhaps due to the fact that in the enclosures, under the annoying attention from people, it is impossible to create a sufficiently romantic atmosphere.
Video with water running on the water can be viewed.
