An insect quickly sliding along the surface of the water. Which living creatures can walk on water and why?
No one can repeat the miraculous walk of Christ on water, except perhaps some representatives of the animal world... What forces help them?
Perhaps the most famous water runner is water strider bug. Almost all their lives, water striders glide along the surface of reservoirs in search of prey; only for the winter they move to land and hide in moss or under the bark of an old stump. But what is the secret of runners? Firstly, thanks low weight and size. Secondly, the entire body of the insect is covered with water-repellent fats, which do not allow the water strider to get wet. And thirdly, the thick-haired cover helps the bug stay afloat, especially on the tips of the legs, which have direct contact with water - up to 16 thousand hairs can grow in one square millimeter. The fur gets wet over time, and if it is not straightened and dried in time, the bug will instantly sink to the bottom.
Feels great on the surface of the water spinning beetle. The beetle's hind legs have been transformed into blades to increase running speed and maneuver sharply. Especially during the mating period, the spinners perform complex pirouettes and twists - the males, picking up speed, make a sharp turn under acute angle and slowly, like dudes in a cool car, they swim past the females, the latter responding with curls and spirals.
Fishing spiders also have a similar technique. A huge number of fibers on the insect’s body, covered with a fatty water-repellent layer, and very little weight allow spiders to easily glide across the surface of the water. Like water striders, spiders stay on the surface on three legs and a pair of legs serve as “oars.”
More can run on water major representatives fauna like lizards, birds and dolphins.
Basilisks live near the shores of reservoirs, hiding in bushes and trees, but in case of danger, he resorts to his amazing ability - to run on water. It stays on the surface of the water thanks to frequent and short splashes. Contact with water lasts only 0.068 seconds. With each swing, the membranes between the toes capture a small amount of air, forming a special cushion that prevents the paw from getting wet. For this miraculous ability, basilisks are called “lizards of Jesus Christ.”
It is easier for birds to run on water than for lizards, since their wings create lifting traction, and the rapid movement of their wide legs helps. Very often, the water runway is chosen by those birds that move slowly and clumsily on land.
The water strider is part of the water strider family, which belongs to the order of bugs (Hemiptera) and is adapted to sliding along the surface of standing water.
External signs of a water strider
Water striders are insects whose name very accurately matches their lifestyle. There are about 700 species of water striders and they all live in water, gliding along the surface of the water with extraordinary ease. With their elongated shape they resemble small boats.
The protective coloration of water striders is brown, dark brown, sometimes almost black. This device allows the water strider to remain invisible to birds against the background of the dark color of the surface of standing reservoirs.
Typically, water striders that live in large bodies of water do not have wings; they simply do not need them.
And the inhabitants of small puddles desperately need wings to fly from place to place as the reservoirs dry up. These water striders have fairly well-developed membranous wings hidden under their elytra, but insects rarely fly.
Movement of water striders on water
Water striders are real virtuosos of gliding along the surface of the water. They are able to use their long legs to run through the water, like speed skaters on smooth ice.
Having encountered an obstacle - a strip of duckweed or other aquatic plants, the “skaters” make deft leaps and overcome the obstacle with strong leaps. The main participation in such maneuvers belongs to the two rear pairs of legs. The water strider's legs are covered with a fatty substance and are not wetted by water, so the insect easily glides along the surface of the water. In addition, during movement, tiny turbulences appear in the water before the next stroke of the limbs. These mini-whirlpools help the water strider move across the surface without any effort, whether in a calm pond or in a restless ocean.
Scientists have proven that water striders of all sizes use their limbs like oars, rowing and transferring momentum to the water mainly through dipole vortices created by their legs. To test this assumption, the researchers created an artificial insect that could move like a water strider.
In English, a water strider is “water strider” or “walking on water.” The robot was called a “robostrider,” and the artificial water strider was able to move through the water like its natural counterpart.
When moving, the water strider spreads its legs wide, evenly distributing its body weight over a large area.
The structural features of the legs are also associated with the movements of insects through water: the thin legs of the water strider at the junction with the body are extremely thick, there are strong muscles that are involved in strong movements.
A water strider cannot drown, even if it is deliberately lowered into the water.
The ventral side of the body is covered with white hairs with a waxy substance, so water does not wet the body and legs of the water strider.
The fact is that air bubbles are held between the smallest hairs. And since the weight of the insect is small, this air prevents the water strider from drowning.
Water strider feeding
Water striders are predators. They feed on insects and small animals that they find on the surface of the water. Having detected prey with the help of large spherical eyes, the predator rushes at it and grabs it with its front legs, the shape of which is similar to a hook. Then the water strider uses its sharp proboscis, piercing it into the body of the victim and sucking out the contents. In a calm state, the water strider tucks its proboscis under its chest. The water strider has rather long antennae, which are organs of smell and touch.
The water strider is a predatory insect. Breeding water striders
Water striders lay their eggs on the leaves of aquatic plants in a single row, with the eggs glued together with a slimy substance. The clutch looks like a long jelly-like cord consisting of about 50 eggs. Some clutches are made without a mucous substance and form a chain of testicles simply lying along the edge of the leaf of an aquatic plant, in this case the testicles are located parallel to each other in one row. Smaller species of water striders simply embed their eggs into plant tissue.
Features of the life of water striders
Water striders are excellent runners on water, but they are absolutely not adapted for long-term movement on land. Therefore, water striders come to land only when it is time to settle down for the winter. They lumber awkwardly along the ground in search of a secluded place. Insects hibernate near water, under bark, in moss or in tree crevices.
The front legs of water striders are shorter than the other legs and are necessary for grabbing food, pushing away when moving, and also for fighting.
Water striders do not miss the opportunity to hold on to their prey. Without dividing the piece, several fighters cling with their forelimbs from a running start, and, unable to resist, fall and roll on the surface of the water. The prey goes to the most cunning and dexterous water strider, which takes the food to a secluded place and devours it while the others sort it out among themselves. With the help of the front legs, the insect regulates the speed of movement, and the other four legs are a support and serve as a rudder.
On our list today - amazing representatives fauna that can move on water:
1. Basilisk Lizard
The Basilisk lizard, also known as the Jesus Christ lizard, hides from predators by falling from the top of a tree and running along the surface of a pond located under the tree. They can run about 4.5 meters, reaching an impressive speed of one and a half meters per second.
The long toes on the hind legs of these lizards are connected to each other by membranes, so by quickly splashing their hind legs on the water they create air pockets, which prevent them from going under water, as long as they maintain their speed. When they do go underwater, they can swim. However, they prefer to run on water to avoid the risk of being eaten by aquatic creatures.
2. Brazilian Pygmy Geckos
This tiny little one is not just adorable, she is also talented. Thanks to its light weight and water-repellent skin, the gecko can easily walk on the surface of the water. Because the gecko is so tiny (they are smaller in size than many of the insects that live in tropical forests Amazon), he risks drowning even in the smallest puddle - scientists believe that this is precisely why their ability to walk on water developed.
3. Water striders 
Water striders belong to the family of water striders, distinguished by their ability to walk on water. They are able to do this thanks to water-repellent legs, which help increase tension on the surface of the water, distributing the insect's body weight equally across all of its legs. Their movements also help them move through water. They push off with the middle pair of legs, making circular movements similar to the movements of oars, and glide forward through the water.
4. Fishing Spiders
Huntsman spiders, also known as dolomedes, are semi-aquatic insects that live near bodies of water where they hunt. They wait on the shore of a body of water until they notice ripples in the water and then run through the water to catch prey. Water also helps them avoid predators, as they can hide just below the surface by enveloping their bodies in tiny bubbles. Although most huntsman spiders feed on insects, larger species may also feed on small fish, tadpoles and frogs.
Like geckos, huntsman spiders can move through water due to their light weight and abundance of short, water-repellent body hairs. Sometimes they swim through the water, putting several legs up so that the wind carries them in the right direction. Their short hairs also allow bubbles to form around their body when they hide below the surface of the water. In fact, they are so buoyant that they have to grab onto something while underwater, otherwise the water will push them to the surface, completely dry. Some types of hunting spiders can stay under water for half an hour.
5. Dolphins
Given that they have no legs, it is difficult to say that dolphins “walk” on water, but they are famous for their ability to dance above the waves using their tail fins. Unlike other animals, which use their ability to walk on water as an evolutionary advantage, scientists say dolphins do it purely for pleasure - for them it's the equivalent of human dancing.
Interestingly, although dolphins can “walk” with their tails, they almost never do this in wildlife. Exceptions are cases when a dolphin who was previously in captivity and undergoing training joined a group of wild dolphins.
6. Western and Clark's Grebes
Both the Western American grebe and Clark's grebe have a unique and beautiful ritual mating games called "rush", in which a pair of birds runs across the water. Birds rush forward with their whole body and stand on their paws on the water, simultaneously flapping their wings. The pair then runs through the water in unison for a distance of approximately 9 meters, making 22 paw strikes per second.
These birds spend almost their entire lives in water. They have short wings and strong legs, which are not very convenient for walking on land, but are indispensable for marriage ritual.
7. Storm petrel
Unlike other animals on this list, this bird does not walk on the surface of the water, although that is exactly the impression it gives. In fact, it hovers near the surface of the water and lowers its paws into it, grabbing prey. The bird's legs are too weak to support its weight for more than a few steps. Because of this, it seems that she can walk longer on water than on land.
8. Heron on a hippopotamus
Herons really can't walk on water, but the bird in this video looks like it can do it - until a hippo emerges above the surface of the water, showing us what the heron's secret really is. She, of course, cannot walk on water, but she got as close to this as possible.
There are a huge number of people living in the world amazing creatures. Some live in the sky, others on the ground, and still others prefer water. However, there are those who skillfully combine all three elements at the same time. water strider And this is exactly what we will talk about in our article.
Water strider insect: why was the little bug called that?
"Water strider" is the name of the beetle, familiar to Russian-speaking countries. Our ancestors came up with this name by looking at the way the insect glides through water. They got the impression that with its movements it seemed to be measuring water. Moreover, this name became so attached to the beetle that even today it is still called. Although in English language his name sounds like water strider, which means “running on water.”
General information about the species
It should be noted that this is a very common insect. The water strider lives almost everywhere, with the possible exception of the cold lands of the Arctic and Antarctic. Scientists classify these creatures as members of the family of hemiptera, a suborder of bedbugs. Today, more than 700 species of water striders are known, which differ not only in appearance and size, but also in their habitual way of life.
Appearance and distinctive features
So, what does a water strider look like? The insect, the photo of which looks more like a floating stick, 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 insect that lives in the sea is considered the smallest.
The main feature of any water strider is its long legs. Often their size exceeds the body of the bug itself. Such proportions are due to the fact that the paws are the key to the survival of the species. After all, they are the ones that allow the insect to quickly glide across the water strider. In total, the water strider has six limbs. She also has wings, but she uses them quite rarely.
Most representatives of this species are painted in dull colors. The most common colors are brown and black. By the way, this color is not accidental - nature specially awarded it to the insect. The water strider is almost always on open space, That's why dark colors, perfectly merging with the water, is its only chance to protect itself from constantly hungry birds and amphibians.
Ability to run on waves
The water strider is an insect whose description always boils down to a story about its amazing ability to withstand the water element. So how does she manage not to drown? The thing is that the bedbug's legs are covered with a special substance that resembles fat in its structure. This creates a kind of barrier that prevents the limbs from submerging in the water.
In addition, the insect knows how to correctly distribute weight: the load does not fall on one point, but is evenly transferred to all six limbs. As for the high speed of movement, it is achieved through fast, impulse strokes. It is they who create turbulence behind the water strider, which pushes it forward.
It is noteworthy that the bug can swim both on mirror-smooth surfaces and among waves. It is this skill that allows water striders to settle on various types reservoirs, which significantly increases their survival rate, and consequently the population.
Diet
Do not think that this is a peaceful insect; the water strider is a real predator. She boldly attacks any small creature that is unlucky enough to find itself on the surface of the water. Such impudence is completely justified, since other insects are not able to fight back, being in an element alien to them.
The hunting principle of water striders is very simple. As soon as the prey falls into the water, they swim up to it with lightning speed and cling to the body with hook-shaped front legs. Then the predator pierces the prey's shell using a sharp proboscis located on the head. Afterwards, the water strider can only suck the liquid from the body of the unfortunate creature.
Features of behavior of water striders
Many people mistakenly assume that this is an exclusively aquatic insect. The water strider really conducts most her life in a pond, but this does not mean that she is not capable of conquering other elements. For example, she has wings that allow her to make short flights. She uses them if her native reservoir begins to dry up and she needs to find a new shelter.
These bugs can also crawl on the ground. They do this very ineptly, since their thin legs constantly get stuck in small cracks and breaks. However, despite this, land is vital for them. The thing is that water striders cannot spend the winter in water, and therefore look for a warm home in the ground or in a tree. Thus, this one is truly unique, because it managed to conquer three elements at once.
Natural enemies
The main enemies of water striders are birds and amphibians. The former catch insects in calm sunny weather, while the latter skillfully track them at the edge of the shore. Naturally, they cannot cause much harm to the population, but individual individuals will clearly have to come to terms with a sad fate.
Before revealing the secret of water striders, it is necessary to remember some basics of the physical properties of water. As is known, the air and water environments are separated by a special film of surface tension. At the boundary of two phases, the attractive forces arising between water molecules are not balanced, i.e. the sum of forces acting downwards turns out to be many times greater than the sum of forces acting upwards. Due to this, the density of the water in the reservoir is slightly higher than in the main water layer.
But that is not all! Molecules tending downward lead to the appearance of a kind of elastic membrane that is capable of supporting objects with a density higher than this on the surface of the water. However, there is one condition: these objects must be dry. If you wet them, they will independently attract water molecules to themselves, which will disrupt the structure of the surface film.
It is curious that these amazing physical properties of the water film are used for their own purposes by various. It is worth moving from physics to zoology. As is known, on the border of two habitats it has a very noticeable advantage. Most famous inhabitants The surfaces of reservoirs are, of course, water striders.
Who are water striders?
These are small insects from the order Hemiptera. Simply put, these are bedbugs. Like their relatives, water striders are equipped with a piercing-sucking mouthparts (proboscis), which allows them to introduce special substances into the body of their prey that paralyze and decompose its tissues. This is necessary in order to suck the finished “broth” out of the victim.
Water striders are predatory creatures. Their main food is insects that accidentally fall on the surface of the water. If the future meal is large enough in size, then several water striders can feast on it at once. However, these creatures prefer to hunt and feed alone.
How does a water strider stay on the water?
This simple ability of water striders is explained by the above physical properties water. This is due to the so-called surface tension force. If we briefly retell the essence of this “trick,” we get the following: in the boundary layer between the air and the water column there are water molecules, which are acted upon from below (from the depths) by a force several times greater than from above. Because of this, a thin membrane is formed on the surface of the water. It is she who holds the water strider, which happily conducts its life activities.
