The underwater world of the pond. From egg to tadpole

Domestic ones caress, but wild ones bite.

They are everywhere and everywhere:

on land, in the sky and in the water,

There are forest ones and swamp ones.

We call them...

ANIMALS

There are a lot of animals in nature, they are all different, but they can be divided into several groups according to common features and habitat.

insects

amphibians

mammals

reptiles

Guess who it is?

I'm growing like a worm. I feed on a leaf, Then I fall asleep, I wrap myself around myself, I don’t eat, I don’t look, I hang motionless, But in the warm spring I come to life again And flutter like a bird.

Insects

Butterfly development

The wren butterfly lays eggs to nettles.

Eggs hatch larvae. Butterfly larvae are called caterpillars. They look nothing like adult butterflies.

The caterpillars feed on nettle leaves, grow quickly, and then become immobile. pupae .

A little time will pass, and from each pupa a butterfly .

caterpillar

Adult insect

This is interesting

Caterpillar growing so fast that her skin is cracking, and underneath there is brand new skin designed to grow.

For all my life female butterfly lays 50,000 eggs.

- Butterfly does not grow, but from time to time she likes to drink sweet flower nectar. This is the fuel that helps it fly.

Butterflies are born to die, giving life to a new generation. Most live only a few days, with the exception of the Monarch butterfly, which can live up to six months.

For my short life a female butterfly can lay more than 1,000 eggs.

The largest moth in the world - this is the Atlas peacock eye (Attacus Atlas). Its wingspan is more than 30 cm, and it is often mistaken for a bird.

The blueberry butterfly (Zizula hylax), which lives in Africa, Madagascar, Mauritius, Arabia and tropical zone Asia and Australia, the length of the front wing is 6 mm.

In the meadows and on the edge, Among the green grass, The cheerful long mustache is skillfully camouflaged! His chirping often hurts his ears, he doesn’t trust anyone - Do you want it, no? And listen! Legs - long to the shoulders, Well! Did you find out? He...

GRASSHOPPER

Grasshopper development

Not all insects can have pupae. Grasshoppers do not have pupae. Their larvae are very similar to adult grasshoppers, only they are very small and do not have wings. Growing up, each larva sheds its skin several times. When does this happen last time, an adult insect emerges from the skin - large and with wings.

adult insect

I swim under the bridge and wag my tail. I don’t walk on the ground, I have a mouth but I don’t speak, I have eyes but I don’t blink, I have wings but I don’t fly.

Fish development

In spring, females spawn into the water caviar .

They emerge from the eggs fry, which look like adult fish,

only very small ones.

The fry feed, grow and become adult fish.

This is interesting

Electric fish. Did you know that some fish can give electric shocks underwater?

For example, electric eel from South America, which

sometimes it grows up to three meters long! Its electric

the discharge is very dangerous and can stun even a horse. Although,

of course, usually the eel attacks frogs and fish, which

feeds rather than on larger creatures. But in case

danger to a person can also attack a person. By the way,

in Africa there lives an electric catfish, which is at least 2 times

and smaller than an eel, but also deadly.

Fish were on Earth more than 450 million years ago. They

appeared before dinosaurs.

flying fish

There are about 40 species of flying fish. The fish accelerates

under water and jumps up actively waving its tail.

The large lateral fins of flying fish allow them to

fly over water up to 400 meters. This skill is volatile

fish are used to escape from predators. Diet volatile

fish consists mainly of small crustaceans and

plankton.

Paws come out of the fry - Long-legged guys. A frog jumps in a puddle - Long-legged...

Amphibians and reptiles

Frog development

In spring, in the pond, river, lake, the loud voices of frogs and toads are heard - real concerts! Female frogs and toads lay in water caviar .

After a few days the eggs emerge tadpoles ,

which look more like small fish than adult amphibians.

Tadpoles live in water, feed, grow and turn into

frogs and toads .

tadpoles

Female lizards, snakes, turtles, and crocodiles lay eggs.

The eggs hatch into small lizards, snakes, turtles, and crocodiles. They grow and gradually turn into adult animals.

Reproduction and development

Adult

animal

cubs

Almost all birds build nests in the spring. Birds lay eggs in nests and incubate them, warming them with their warmth. The chicks grow quickly and need a lot of food.

In late spring and early summer, the chicks of many birds leave their nests. Although they are already covered with feathers, they still fly poorly. They also cannot feed themselves yet. Parents feed their chicks for some time and protect them from enemies.

Reproduction and development

Adult bird

This is interesting

The cuckoo does not build its nest and does not hatch eggs, which

she demolished it. And he puts them in the nests of other birds, like

rule for singers.

Sometimes a cuckoo manages to spread up to 20 of its eggs into other people's nests.

The cuckoo tries to push out

from the nest other eggs and even small chicks so that he

got more food. Soon the little voracious cuckoo

becomes larger than their adoptive parents, who

exhausted to feed the foundling.

Animals

Animals, or mammals, give birth to young and feed them with milk. Most mammals give birth to their young in the spring. For a fox they live in a hole, for a squirrel - in a hollow or in a nest in a tree, for a beaver - in a hut. Fox cubs and squirrels are born blind and helpless. But beaver cubs are born sighted. Most animals take care of their offspring.

Reproduction and development

Adult animal

Interesting facts

The blue whale is the largest animal on the planet. It can reach a length of 33 m and a weight of 150 tons. Cubs are born with a length of 6 to 8.8 m and a weight of 2-3 tons. Blue whales found in almost all areas of the World Ocean.

Since whales are mammals, their calves, like the calves of other animals of this class, are fed with mother's milk. They are not hatched from eggs like fish, but are born alive and remain with their mother for some time after birth.

Whales do not have gills; they breathe through lungs. Their caudal fin is located horizontally and helps them easily rise to the surface of the water when they need to breathe.

A newborn elephant calf weighs 90-120 kg with a shoulder height of about 1 m, its trunk is short, and there are no tusks. 15-30 minutes after birth, the baby elephant rises to its feet and can follow its mother. Until the age of 4, he needs maternal care.

This is interesting

Fill in the missing words

In insects, _________ emerge from eggs, and in birds, ________.

Caterpillars feed _________ and then turn

in stationary _________.

In fish, _________ are hatched from eggs, and in frogs and toads -

Animals give birth to ___________ and feed them _________

leaves

tadpoles

Final multi-level tests on the world around us.

3rd grade
I level

1. Write down the spring months in the order they appear.

3. View daily temperature records. Can we consider that spring has arrived in nature?

4. Write down which spring month Celebrating Earth Day?

5. Indicate with arrows which month the birds listed below arrive in your region:

-oriole MARCH APRIL MAY

-martin

-nightingale

-rook

-lark

-starling

-wagtail

-geese

6. Mark the plants that bloom in spring.

Birch, willow, linden, bluebell, primrose, chamomile, snowdrop.

7. Look at the drawing of a flowering plant, label its organs and fill in the missing ones.

Poppy: flower, fruit, root, leaf, seeds, stem.

8. Mark green medicinal plants, blue - poisonous, red - protected.

-yarrow

-celandine

-lady's slipper

-ginseng

-buttercup

-henbane

9. Fill in the missing words.

Plant seeds are spread by _____________, _________

And ___________________ .

10. Label the parts of the escape.

11. Mark simple leaves in green, complex leaves in red.

Leaves of rowan, birch, ash, rose hip, raspberry, gooseberry, tulip, yarrow, nasturtium.

12.What gas do plants need for respiration?

13. Connect adult animals and their larvae with lines.

Frog and tadpole, butterfly and caterpillar, Colorado potato beetle and larva, ladybug and larva.

14. What is most dangerous to human life in the spring?

Level II
1. How will the height of the Sun in the sky change after March 21?

2. View the thermometer readings. At what time of year are such air temperatures possible?

10 0 , -5 0 , 0 0 , +4 0 , 0 0 , +6 0

3. Indicate with arrows what material birds’ nests are made of.

magpie, rook, lark, swallow, crane

from branches, from dry grass, from clay, from moss and grass

4. Write down by what characteristics plants are classified as living organisms.

5. Mark the names of plants that have complex leaves in green, and simple ones in yellow.

Rowan, clover, linden, birch, geranium, dandelion, yarrow, tomato, pea, maple.

6. Fill in the missing words.

Plants, like us, need ____________ to breathe, which they absorb from the air. Plants, like us, emit ____________ gas into the surrounding air.

7. Why are plant flowers brightly colored and scented?

8. Label parts of the sheet.

(leaf blade, stalk, veins)

9. Write down where you can meet:

-butterfly egg

-fly egg

-chafer larva

-an ant pupa

-tadpole

10.Insert the missing word, observing the order of the stages of animal development.

Egg, ______________, adult bird.

Egg, ______________, pupa, butterfly.

Egg, fry, __________________.

Egg, tadpole, ________________.

Egg, larva, ______________, ladybug.

Level III

1. From which month and for what period will the day be longer than the night?

2. What can you say about the time of year by looking at the daily temperatures for a week?

+4 0 , +10 0 , +6 0 , +3 0 , -1 0 , +5 0 , +4 0

3. Write down examples of plants that do not have either a root or a flower.

No root: _____________________________________________________

No flower: _____________________________________________________

4. What is the name for the phenomenon of almost simultaneous shedding of leaves in some plants? In what tree species does this phenomenon occur?

5. Draw examples of leaves indoor plants, differing in size, shape, color, and different types of venation.

6. Mark the “extra” word in each row. Justify your choice.

Pine, spruce, fir, maple.

Lilac, raspberry, nettle, hazel.

Root, leaf, stem, lily of the valley, stem, flower.

Egg, egg, butterfly, pupa, caterpillar.

Egg, frog, fry, tadpole.

7. Make a crossword puzzle using the names of plant organs.

8. Draw the stages of development of some animal (butterflies, frogs, fish, birds,...) and indicate their sequence with arrows.

The world of a freshwater pond is amazing and diverse. This summer I tried to photograph some of its most characteristic inhabitants. Posed: tadpoles - frog larvae, water bug, common pond snail (lymnaea stagnalis), Great false horse leech (Haemopis sanguisuga), dragonfly larvae.

Tadpoles:

The tadpole is so named because big head, there are no limbs, the caudal section of the body is a fin, there is also a lateral line, and there is a suction cup located below the mouth (you can use it to determine the type of tadpole), after a few days the mouth slit along the edges is overgrown with some semblance of a beak, which works like nippers when the tadpole eats. Tadpoles have branchial openings and gills. At first they are external, but over time they change, attach to the gill arches located in the pharynx area, and function as real internal gills. The tadpole has one circulation and a two-chambered heart.
In terms of body structure, amphibian larvae are close to fish, and adults are similar to reptiles.
After 1-3 months, their hind legs grow first and then their front legs, and their tail shortens and falls off. The lungs are developing. The tadpole begins to rise to the surface of the water and swallow air. Change and growth happen faster the warmer the weather. Tadpoles at first feed mainly on plant foods, but gradually switch to more and more animal foods. A formed frog or toad is chosen to land if it land species or continue to live in water, if the species is aquatic. Teenagers who come ashore are called “yearlings.” In amphibians that lay eggs on land, a transition to development without metamorphosis is sometimes observed, i.e., direct development. From the moment the eggs are laid until the end of the transformation of the tadpole into a frog, about 2-3 months pass.

Prudovik:

This snail has a huge habitat and is found in almost all fresh and some brackish water bodies of Europe, Asia, North Africa and North America.
The height of the spiral shell, twisted in 4-5 turns, is usually about 4 cm, width - 2.5 cm. The shells of the largest specimens of the large pond snail reach 7 cm.
The size, as well as the color and strength of the pond snail's shell, the shape of its mouth and curl, strongly depend on the habitat. The shell is usually brownish, and the body can be black-blue to sandy yellow.
The body shape of a large pond snail follows the shape of the shell, fitting tightly to its walls. The head is large, with flat triangular tentacles. U inner edge The eyes are located at the base of the tentacles. The mouth, located on the underside of the head, is equipped with a muscular tongue covered with teeth - a grater.
The pond snail breathes both oxygen dissolved in water and atmospheric air, drawing it through the breathing hole into the pulmonary cavity 6-9 times per hour.
Pond snails are almost always active. They crawl along the leaves of plants, scraping algae and particles of organic matter from them with a grater. These snails also feed on the remains of rotting plants and animals. In addition, they swallow fine sand, which helps them grind food in their stomach.
Pond snails can also move “upside down” on the surface tension film of water. To do this, they reduce their weight by filling the respiratory cavity of the mantle with air. When in danger, the evidence releases this air and falls to the bottom.
The pond fish is a very tenacious creature. It can freeze into ice and then thaw; it can wait out drought by burying itself in silt or sealing the mouth of the shell with a thick film.

False horse leech:

About 10–15 cm in length. Its color is greenish or brownish-black.
Body with two suckers - one at the front, the other at the rear end.
Breathing occurs through thin skin.
Distributed in ponds, rivers, ditches, and also comes ashore.
The leech is a voracious predator. It not only sucks the blood of various animals, whose skin it is able to bite through, but also devours the prey entirely. The victim is mollusks, various worms, insect larvae, and sometimes it even attacks fish.
When breeding, the leech lays eggs in cocoons made of mucus. Cocoons are buried in the ground near water. The eggs hatch into young leeches that grow slowly and reach maturity after a few years. The muscular body of leeches is capable of sharp contraction and stretching. Making wave-like movements, the leech easily swims under water. But on damp soil, in moss or in rotting products, it can for a long time be out of the water.
The leech’s “rubber” stomach allows it to consume large amounts of food at one time. Having grown fat from the blood of its victims, the leech can then go without food for 4 to 6 months.
False-cone leeches are a living barometer. Before good weather, they lie calmly on the bottom or swim leisurely. In the face of a strong wind, leeches scurry restlessly back and forth. If it rains in the next 24 hours, they either lie motionless in the water, or, half sticking out of the water, hang vertically one next to the other. Before a thunderstorm, leeches begin to wriggle convulsively and stick to the glass above the water or even to the glass lid of a jar.
When a leech sucks blood, it salivary glands secrete hirudin, a substance that prevents blood clotting. Blood flows freely into her stomach, which is equipped with outgrowths - pockets that increase its volume. A leech can “drink” 50 g of blood at a time. In her intestines, special bacteria process the blood so that it does not spoil and remains fresh for a long time. Therefore, leeches feed approximately once every six months, and can starve for up to two years. Leech bites are painless, because the victim does not feel the bloodsucker's suction. If a leech has attached itself to the body, there is no need to tear it off (there will be a wound), it is better to sprinkle it with salt, lubricate it with iodine (alcohol, cologne), and cauterize it.

Dragonfly larvae:

Dragonfly larvae are found everywhere in standing and slowly flowing water. Most often they are found on aquatic plants or on the bottom, where they sit motionless, sometimes moving slowly. There are species that burrow into the mud. The larvae move either by swimming or crawling. In general, they are very little mobile; in the aquarium they do not move for hours at a time, clinging to underwater plants with their long, clawed legs. If the larva is slightly disturbed, it slowly moves to another place, clumsily rearranging its legs. With a stronger push, the larva quickly takes off from its place and, pressing its legs to its body, swims with strong jerking movements, the cause of which is sometimes not immediately apparent. Upon closer observation, it turns out that the larva takes water through the anus into the hindgut, and then from great strength throws her out of there. With this “water shot,” the insect’s body, due to recoil, is pushed into opposite direction, exactly on the same principle as a burning rocket flies, gases escaping from the rear hole. This method of movement deserves attention because it is rarely found in the animal world (for example, in cephalopods). Dragonfly larvae feed exclusively on live prey, which they stand motionless for hours on end, sitting on aquatic plants or on the bottom. Their main food is daphnia, which they eat in huge quantities, especially by younger larvae.

Among the many animals, only the so-called invertebrate animals reproduce asexually. Vertebrates - such as mammals, fish, reptiles, birds and amphibians - reproduce sexually: sperm and eggs, carrying the hereditary material typical of a given animal species, are united during fertilization. A fertilized egg is called an embryo.

Depending on the species of animal, the embryo can develop both inside and outside the mother's body. Gradually, small cubs develop from fertilized eggs in accordance with the genetic instructions embedded in it. Many, such as frogs, go through one more stage of development before becoming fully grown.

From egg through larva to adult animal

Snails live on land, in running water and in the seas. Sea slugs lay eggs in sea ​​water, which after high tide get stuck between the rocks. From fertilized eggs, larvae (veligers) emerge that can swim. They swim with the current and finally sink to the rocky bottom, where they develop into adult crawling clams.

Fertilized egg

The red spot in the middle of the egg yolk is a three-day-old chicken embryo. After a week, the embryo already takes the shape of a chicken. After a month, the chicken is already fully developed and covered with delicate down. With the egg tooth on his beak, he breaks the egg shell and comes out into the light. The chick hatches and becomes an adult without any additional developmental stage.

From egg to tadpole

During mating season, many frogs gather in large, noisy groups. Females respond to loud calls from males. Only a few species of frogs give birth to live young; most species lay eggs (spawn) in or near water. The number of eggs depends on the type of frog and ranges from one to twenty-five thousand. Typically, the eggs are fertilized outside the frog's body and left to fend for themselves. When the egg matures, a small tadpole hatches from it. Tadpoles live in water and breathe through gills, like fish. In only a few species of frogs, females care for their young.

Frogs and Toads

Unlike adult frogs, tadpoles are herbivorous and feed on aquatic plants and algae. After a certain time, an amazing transformation (metamorphosis) occurs in the development of the tadpole: fore and hind limbs appear, the tail disappears, lungs and eyelids develop, and new systems digestion, designed to digest animal food.

The conversion rate is different for different types, the main factor here is water temperature. In some toads and frogs, metamorphosis occurs in a few days or weeks, while in others it takes several months. The tadpole of the North American bullfrog takes a year or more to fully develop.

Frogs and toads belong to the class of amphibians and to the same group of tailless amphibians, but they differ appearance and way of life. Frogs have soft skin and are good jumpers, while toads are covered in warts and tend to crawl. There are more than 3,500 species of frogs and toads on earth. With the exception of Antarctica, they can be found on all continents. They prefer to live in tropical and subtropical zones, where more than 80% of all species live. But no matter where they live, in deserts or mountains, savannas or tropical rain forests, they must return to water to procreate.

What is metamorphosis

In their development, frogs go through three stages: from egg to tadpole, and then to adult frog. This developmental process is called metamorphosis. Many invertebrates also go through the larval stage in their development. However, the most amazing changes occur in the lives of insects: butterflies and beetles, flies and wasps. Their life is divided into four stages, very different from each other in their feeding method and habitat: egg, larva, pupa, adult insect. The larva looks completely different from the adult insect and does not have wings. Her life is completely focused on growth and development, and not on procreation. Only after the larva pupates does it become an adult insect.

Butterflies (larvae). Surprisingly, caterpillars of many butterfly species can be found in water. Caterpillars of some species build houses (similar to those made by caddisflies) from parts of plant leaves. The duckweed moth, for example, builds a house out of duckweed. All these caterpillars are herbivorous. Before pupation, they emerge from the water onto the above-ground parts of plants. Caterpillars are hardly noticeable in a pond, but traces of their vital activity are sometimes noticeable - some of them can seriously harm ornamental aquatic plants.

Twirly. These little ones water bugs They are especially noticeable on the surface of the water in good weather - they quickly rush along the surface of the water, cutting through it like speedboats. Disturbed, they quickly dive into the water. Circling through the water, they hunt small aquatic animals, looking for them both in the water column and on its surface (in the latter case, competing with water striders). The whirligigs are close relatives of the diving beetles. Their larvae are also predators and also suck out their prey. Only they are very small, live in silt or among plants and hunt small aquatic creatures, and therefore are harmless and harmless.

Water lovers. In contrast to swimmers and whirligigs, water lovers are non-predatory beetles. This is immediately noticeable by their lack of powerful jaws. Usually in our ponds there are large and small water lovers with a body length of about 4 and about 1.5 cm, respectively. Unlike diving beetles, water lovers swim poorly and usually crawl among aquatic plants, which they feed on. However, water-loving larvae are predators, consuming young fish and tadpoles. A remarkable adaptation of water lovers is with which they breathe atmospheric air: the beetle carries an air bubble captured from the surface of the water on its abdomen.

Water striders. This name brings together several peculiar bugs that have adapted to life on the surface of the water. The most noticeable inhabitant of our reservoirs is the great water strider. Its torpedo-shaped body reaches a length of 1.7 cm and is covered with tiny hairs, giving it a velvety appearance and preventing wetting. Well-developed wings and elytra are located along the back, although this insect cannot be seen flying. The front legs are very short and are used only for capturing and holding prey. And the two rear pairs are very long and thin. They are lubricated with a fat-like substance, thanks to which the water strider glides easily and gracefully across the water surface. Throughout the summer, females lay eggs on the surface of the water, from which tiny water striders hatch. In autumn, insects leave the pond and hide on the shore under some objects. Water striders are harmless and beautiful inhabitants of water bodies.

Water scorpions. An amazing aquatic monster - a kind of bug with a leaf-shaped, flattened body. The length of our usual water scorpion is 2 cm. It is completely flat and wide, grayish or brown, crawls along the bottom of a reservoir with the help of two hind pairs of paws, and its front ones are transformed into grasping claws, which is why it really looks like a scorpion. A bug hiding at the bottom is very difficult to notice, but as soon as some small aquatic animal approaches it, it immediately throws its claws forward and grabs it. The unique appearance of the water scorpion is added by the sword-shaped appendage at the end of the body. This is a breathing tube, which, when exposed to the surface, the bug breathes. Close relative water scorpion - Ranatra - has a long and narrow body and is somewhat reminiscent of a stick insect. There is no harm from water bugs, and with their amazing appearance they significantly diversify water world pond.

Gladyshi - bedbugs visible in the pond. They have a peculiar body shape, reminiscent of an inverted boat: convex on top and flat on the bottom. Well-developed smooth (hence the name of the animal) elytra of olive or yellowish color. The back pair of legs are transformed into powerful oars, allowing the bug to quickly scurry through the water. While swimming, the smoothie turns over with its ventral side up, while its eyes are directed downwards and looks for prey. The smoothie is a predator that attacks fairly large inhabitants of the reservoir. At the same time, the most common species - the common smoothie - does not exceed 1.5 cm in length. It strikes prey with a strong, sharp proboscis. A carelessly picked up iron can painfully pierce a person's skin. IN decorative pond appears quite suddenly, because it flies well and travels long distances at night in search of new bodies of water. In garden ponds and aquariums (introduced with live food) it harms juvenile ornamental fish.

Greblyaki - small water bugs, very common in shallow bodies of water. The largest of those found in Ukraine reaches 1.5 cm in length. They have an elongated flat body and three modified pairs of legs: the first is short, spatulate, with their help the male makes noises under water musical sounds, attracting a female; the second - with claws, with which the bug clings to aquatic plants; the third pair is a rowing pair, which helps the insect to swim quickly. Paddlers live constantly in the water and are active even in winter, under the ice. They feed on algae and small aquatic invertebrates. Harmless.

Daphnia. This name unites several species of cladocerans. The largest ones reach a length of 6 mm. Even the naked eye can see that the laterally flattened round body of these crustaceans. covered with a double-leaf transparent shell. There are forked antennae at the top: hitting the water with them, the crustacean moves upward in small jumps. Daphnia filter water, capturing and eating various microorganisms from it.

In spring, daphnia reproduce unusually quickly, forming greenish, orange or yellowish clouds swirling in the water column. Fertilized daphnia eggs can withstand drying and frost, due to which the number of crustaceans quickly recovers after unfavorable periods. A very useful animal - it purifies water, serves as complete nutrition for other aquatic inhabitants and is used for feeding aquarium fish.

centipedes (larvae). Long-legged mosquitoes are known to everyone who has traveled outside the city. These large, tough, poor-flying mosquitoes are a terror to children. But they are completely harmless. Their larvae, like the larvae of other mosquitoes, live in water or in wet soil. They look like caterpillars with a well-developed head and gnawing jaws. They feed only on plant foods - both living plants and dying remains.

Squeaker mosquito (larvae and pupae). This is exactly the mosquito that annoys us in the summer. Its larvae differ from the larvae of other, harmless mosquitoes in being gray in color and a large number bristles on the body. It should be noted that the larvae of the squeak mosquito, like its dangerous relative malaria mosquito, feed by filtering water and scraping off growths on underwater objects, and thus act as orderlies of the reservoir. Malaria mosquitoes are found in more southern regions; their larvae differ from the squeak larvae in the position of their body at the surface of the water: the breathing larva of the malaria mosquito is located horizontally, and the squeak larva hangs upside down.

Mosquitoes (larvae and pupae). The larvae of mosquito mosquitoes, or bells, are a well-known bloodworm, widely used by aquarists and fishermen. Mosquitoes themselves are small, harmless insects that swarm summer evenings near bodies of water. The bloodworm lives in silt, where it builds web-like tube houses and feeds on bottom microorganisms. Dergun larvae are valuable food for many pond inhabitants and aquarium fish. Koretra (larvae). The larvae of mosquitoes of the genus Koretra are colorless and float in the water column thanks to air bubbles in the front and back parts of the body. Larvae are predators that feed on small planktonic organisms and can also attack small fish fry. The mosquitoes themselves are harmless.

Hover flies (larvae). In the water there are larvae of not only mosquitoes, but also other dipterous insects, in particular horse flies, lion flies, and hoverflies. They look like small, translucent caterpillars and feed primarily on plants and decaying organic matter.

Wonderful larvae common beekeeper , called "rat". The barrel-shaped, loose and vaguely segmented body of this unpleasant creature ends at the end with a long “tail” - a breathing tube, sometimes extended by 15 cm! With the help of this device, the larva breathes while digging in the fetid silt of rotting reservoirs. The adult fly mimics a bee, hence its name.

Leeches - unattractive inhabitants of bodies of water, usually causing fear and disgust. You need to be wary of blood-sucking - medical and horse - leeches, but they live in the southern regions (the horse leech is not found in Ukraine, and the medical one can be found only in the south of the European part of the country). Leeches, which are common in our reservoirs, are not dangerous to humans. The most noticeable of them is the large false horse leech, whose body length can exceed 10 cm. It settles in lakes and small drying puddles; also lives in damp soil. The large false horse leech is a formidable predator for the soft-bodied and slow-moving inhabitants of the reservoir. In the water column, this leech swims confidently, without hiding, wriggling its black flat body in waves - it has practically no enemies.

Small false horse leeches are no longer than 5 cm and are painted in lighter colors. They are almost harmless - only dangerous to small worms and mosquito larvae. False-cone leeches do not harm fish and frogs; Fish leeches, which are dangerous for them, are not found in shallow stagnant bodies of water.

Swimming beetles. Aquatic swimming beetles are conspicuous inhabitants of the reservoir. Moreover, both the beetles themselves and their larvae are noticeable. It is difficult to see only the pupae of these insects - the fact is that for pupation, the grown larvae come to land and burrow into the ground. The largest of our common swimmers reach a length of 4 cm. They are dark-colored, with a smooth, rounded body covered with hard elytra. Swimming beetles fly beautifully and therefore can appear in any body of water. Both they themselves and their larvae are ferocious predators, attacking even small frogs and fish. Beetle larvae are large, segmented aquatic animals that move quite quickly along the bottom and in the water column using synchronous movements of three pairs of legs. They differ from dragonfly larvae in their small eyes and powerful mandibles. There are channels in their jaws, with their help the larvae of the diving beetles suck out the contents of the victim’s body - you can often see the larvae of the diving beetle swimming with half-sucked prey. With its powerful jaws, the larva is capable of biting through human skin. Swimming beetles and their larvae are undesirable in bodies of water where there are juvenile amphibians and fish. But in themselves they are beautiful and vibrant representatives of the underwater world.

Mayflies (larvae). Mayflies, or mayflies, are small winged insects that got their name because they often live only a few hours. But these are adults. But their larvae - “long-livers” - spend two to three years in the water. Adult insects do not feed and do not even have the organs necessary for this - they only lay eggs in the water, from which larvae hatch, called, like dragonfly larvae, naiads. The larvae are small, with three pairs of legs and three long tail filaments, with which they swim. Naiads of various species feed either on decaying organic remains or catch small aquatic animals. In turn, they serve as food for many inhabitants of the reservoir. They are certainly useful in a garden pond.

Rotan-gatyuvegica - a small Far Eastern goby that has spread widely across the territory of our country. Easily acclimatized. Many aquarists and fishermen are constantly tempted to release this fish to a new place. This is absolutely not allowed! As a fish, it is completely useless (body length is usually no more than 10 cm); No one will see its extraordinary spiky appearance anyway, since it constantly rummages in the silt, but all other living creatures in the reservoir will come to an end with the appearance of rotan - it will eat everyone. The natural ecological balance will be disrupted, and the reservoir will turn into a dirty puddle.

Caddis flies (larvae). IN clean pond At the bottom you can see strange “objects” - small tubes made from bottom debris, but slowly moving and clearly alive. These are caddisfly larvae. The caddis flies themselves are inconspicuous winged insects similar to moths. But their wings, unlike butterflies, are covered not with scales, but with hairs. Like mayflies, adult caddisflies do not feed, but only reproduce. They lay their eggs in the water, and the larvae that hatch from them immediately begin to build themselves a house from the cobwebs secreted by them. salivary glands. The larvae include various available materials in the walls of the house - grains of sand, pieces of dead plants, wood chips, etc. Fancy tube-houses are formed that protect the delicate worm-like body of the larva. The larva hides in this house and drags it along with it, moving along the bottom in search of food - plant debris and small animals (for example, mosquito larvae). As the larva grows, it completes its shelter. Growing up to required size, the larva turns into a pupa, which looks like a smooth bug and floats freely in the water column. Having reached the shore, the pupa crawls onto land, where the adult caddisfly hatches. Caddisfly larvae are funny and useful inhabitants decorative pond.

Dragonflies (larvae). Water bodies always attract dragonflies. Small graceful multi-colored even-winged dragonflies (arrows, lute, beauties) flutter along the shore, periodically perching on semi-aquatic plants. Larger and more powerful dragonflies of different wings (rockers, headstocks, true dragonflies) fly over the surface of the water with a loud chirping sound. Females periodically hover over the water, dipping the tip of their abdomen into it, and lay eggs. The eggs soon hatch into larvae - permanent and very visible inhabitants of reservoirs (they are called naiads). The larvae, like the dragonflies themselves, have huge hemispherical eyes and three pairs of long, jointed legs. There is nothing else in common in the appearance of parents and children. Naiads of homoptera are long, thin, slender, while naiads of heteroptera are massive. Both crawl along the bottom and underwater objects or swim in the water column, moving with the help of long legs. They breathe oxygen dissolved in water. To do this, the larvae of homoptera use beautiful gills-feathers located in the back of the abdomen, and heteroptera pass water through the intestines, in which gas exchange occurs. Dragonfly larvae are predators, and heteroptera naiads can even attack large tadpoles and fish fry. For hunting, dragonfly larvae have a peculiar device - a mask, which, when folded, is hidden in the lower part of the head. Straightening up, it throws itself far forward and, with the help of movable blades, captures the victim, and folding again, delivers it directly to the naiad’s mouth. When the dragonfly larva reaches necessary development, she crawls out onto the stem of some coastal plant and, leaving the water, undergoes an amazing transformation. The covers on its back burst, and a beautiful dragonfly gradually crawls out of the larva. It dries out for a while and then flies away. Dry skins of naiads can be seen on coastal plants for a long time. The larvae of homoptera dragonflies develop in one season, and the larvae of heteroptera dragonflies spend one to two years in water. Dragonfly larvae are safe, but handling the tough and strong dragonfly naiad is unpleasant. They are beautiful in a pond and cannot cause significant harm.

Pipe makers - small annelids with very thin body several centimeters long. On a natural bottom through clear water you can see how numerous pinkish hairs protruding from the ground fluctuate rhythmically. This is how the pipe maker breathes. He himself is immersed in silt, and the back part of his body sticks out - gas exchange occurs through it. To activate this process, the worms create a current of water by wriggling these “tails.” At this time, they themselves swallow the silt, assimilating from it the rotting remains of plants and animals. Thus, they are the orderlies of the bottom of the reservoir (by the way, up to 100 thousand tubifex worms can live per 1 m2 of reservoir!). They also serve as food for other aquatic life and aquarium fish.

Snails. A variety of small snails—shell molluscs—settle quite easily in shallow, stagnant bodies of water. The most famous and widespread are - reels and ponds . The coils have a flat shell - it curls in one plane. In the pond you can find a fairly large - about 3 cm in diameter - horny coil, the shell of which is quite hard, colored brown, and the so-called leg is blue-black. Smaller coils have almost transparent shells with a diameter of no more than 1 cm, usually they are large quantities settle on the underside of large leaves of plants such as nymphs or egg capsules. On underwater plants you can often find a small yellow-brown snail with a conical shell twisted (a very important feature for taxonomy!) to the left.

This - Physa vesicularis . A much larger mollusk with a pointed shell twisted to the right is the pond snail. We have several species of them, the largest is the common pond snail with a shell reaching 7 cm in length. Pond snails spend a lot of time directly at the surface of the water, since they cannot do without air for a long time, which they receive through a breathing hole that opens on the side of the leg. The ability of these large snails to crawl along the surface of a reservoir with their shell downwards is amazing, holding themselves there thanks to the surface tension of the water.

The biology of snails has a lot of interesting things for naturalists. So, all of them are hermaphrodites, that is, each individual has both male and female reproductive systems. They reproduce by laying clutches of small transparent eggs, from which tiny snails hatch. Snails - inhabitants of small bodies of water - have various and amazing adaptations that help them survive favorable conditions(drying out, freezing). During such periods, the snails clog the mouth of their shell with a layer of mucus and fall into a kind of hibernation. Some of them are able to crawl on land and climb into the ground. Others have a short one life cycle. Thus, the physa grows quickly, lays eggs and dies, so it can only be found in the first half of summer, and its clutches overwinter in the reservoir.

Reels are completely safe in the pond. They can only feed on soft, decomposing organic remains and this, of course, only brings benefits. The tiny physa is no longer so harmless - it eats the eggs of other animals (for example, the eggs of fish or newts). A big pond snail- a real pest. A voracious eater of everything, it destroys any aquatic vegetation and has no place in a decorative pond.

Cyclops. Aquarists call various copepods cyclops. The body length of the largest cyclops rarely exceeds 5 mm. Their transparent body is divided into segments and at the end has forked processes that facilitate the swimming of crustaceans. Cyclops move through the water using sharp movements of their antennae. They feed mainly on microorganisms, but can also attack tiny fish larvae.

Shield. A rather little-known and very interesting crustacean. It can suddenly appear in any shallow body of water, surprising anyone with its fantastic appearance. The rather large (up to 5 cm) body is covered on top with a solid black flat oval shield, from which extends a long forked “tail”. The unpredictability of the appearance of shieldfish in a reservoir is explained by the fact that their small eggs, covered with hard shells, tolerate both drying and freezing, maintaining viability for up to nine years. At the same time, they are easily transported by the wind and do not die in digestive tracts, for example, frogs. When they find favorable conditions, they hatch into larvae, which grow quickly and periodically molt (up to 40 times) and can turn into an adult in just two weeks.

Shield bugs burrow through the mud, eating decaying organic matter. They do not cause any harm to the reservoir and, despite their menacing appearance, are completely harmless. With their unusual “prehistoric” appearance they will only enliven the pond. By the way, the shieldfish can really be called a living fossil, since these animals have not changed at all over the past 200 million years.