Spider refers to an animal or insect. The most famous and dangerous spiders in Russia

Spider (lat. Araneae) belongs to the phylum arthropod, class Arachnida, order Spiders. Their first representatives appeared on the planet approximately 400 million years ago.

Spider - description, characteristics and photographs.

The body of arachnids consists of two parts:

• The cephalothorax is covered with a shell of chitin, with four pairs of long jointed legs. In addition to them, there is a pair of claws (pedipalps), used by mature individuals for mating, and a pair of short limbs with poisonous hooks - chelicerae. They are part oral apparatus. The number of eyes in spiders ranges from 2 to 8.
• Abdomen with breathing holes located on it and six arachnoid warts for weaving webs.

The size of spiders, depending on the species, ranges from 0.4 mm to 10 cm, and the span of their limbs can exceed 25 cm.

The coloring and pattern on individuals of different species depend on structural structure covers of scales and hairs, as well as the presence and localization of various pigments. Therefore, spiders can have both dull, monochromatic and bright colors of various shades.

Types of spiders, names and photographs.

Scientists have described more than 42,000 species of spiders. About 2,900 varieties are known in the CIS countries. Let's consider several varieties:

Blue-green tarantula (lat. Chromatopelma cyaneopubescens)– one of the most spectacular and beautifully colored spiders. The tarantula's abdomen is red-orange, its limbs are bright blue, and its carapace is green. The size of the tarantula is 6-7 cm, with a leg span of up to 15 cm. The spider’s homeland is Venezuela, but this spider is found in Asian countries and in African continent. Despite belonging to tarantulas, this type does not bite spiders, but only marks special hairs located on the abdomen, and only in case of severe danger. The hairs are not dangerous for humans, but they cause minor burns on the skin, similar in effect to nettle burns. Surprisingly, female chromatopelma are long-lived compared to males: the lifespan of a female spider is 10-12 years, while males live only 2-3 years.

Flower spider (lat. Misumena vatia) belongs to the family of side-walking spiders (Thomisidae). Color varies from completely white to bright lemon, pink or greenish. Male spiders are small, 4-5 mm long, females reach sizes of 1-1.2 cm. Species flower spiders distributed throughout European territory (excluding Iceland), found in the USA, Japan, and Alaska. The spider lives in open areas with an abundance of flowering herbs, as it feeds on the juices of those caught in its “embraces” and.

Grammostola pulchra (lat. Grammostola Pulchra)- a species that in its natural environment lives only in Uruguay and in southern regions Brazil. A rather massive spider, reaching a size of 8-11 cm, with a dark color and a characteristic “metallic” sheen of hairs. In nature, it prefers to live among the roots of plants, but almost never digs its own burrows. Pulhra often becomes a pet among connoisseurs of exotic pets.

Argiope Brünnich or wasp spider (lat. Argiope bruennichi) – a spider with an unusual coloring of the body and limbs - yellow, black and white stripes, for which it received its name. True, the male wasp spiders are not so bright, and they are smaller in size than the females: the “young ladies” reach a size of 2.5 cm, and together with the legs - 4 cm, but the male rarely grows more than 7 mm in length. The species is widespread in Europe, Asia and southern Russia, the Volga region and North Africa. The Argiope spider lives in meadows with an abundance of grass, on the edges of forests. The web of the argiope is very strong, so it is difficult to tear it, it will only stretch under pressure.

Hunter bordered (lat. Dolomedes fimbriatus) widespread on the Eurasian continent and occurs along the shores of bodies of water with standing or very slow flowing water. Often settles in swampy meadows, shady forests or gardens with high humidity. The body length of the female edge hunter varies from 14 to 22 mm, the male is smaller and rarely larger than 13 mm. The color of spiders of this species is usually yellowish-brown or almost black, with light yellow or white stripes on the sides of the abdomen.

(lat. Lycosa tarantula)- a species of spider belonging to the family of wolf spiders (lat. Lycosidae). Lives in the open spaces Southern Europe: often found in Italy and Spain, digs burrows half a meter deep in Portugal. The size of the tarantula is impressive - up to 7 cm in length, individuals are usually colored red, less often - brown, with several transverse stripes on the body light color and one longitudinal.

Spiny orb-weaving spider or "horned spider"(lat. Gasteracantha cancriformis) distributed in the tropics and subtropics, in the southern part of the USA, Central America, the Philippines, and Australia. The size of the female is 5-9 mm, the width reaches 10-13 mm. Males are 2-3 mm long. The legs of the spiny spider are short, and there are 6 spines along the edges of the abdomen. The color of the spider is very bright: white, yellow, red, black. On the abdomen there is a pattern of black dots.

Peacock spider(lat. Maratus volans). The color of this spider comes in all sorts of colors: red, blue, light blue, green, yellow. The coloring of females is paler. An adult reaches a size of 4-5 mm. Males attract females with their beautiful outfit. The peacock spider lives in Australia - in Queensland and New South Wales.

Smiling spider (lat. Theridion grallator) or a spider with a happy face is completely harmless to humans. This unusual spider lives in the Hawaiian Islands. Its body length is 5 mm. The color of the spider can be varied - pale, yellow, orange, blue. This species feeds on small fish, and the bright coloring of the individual helps confuse enemies, especially birds.

Black Widow (lat. Latrodectus mactans)- This is a very dangerous and poisonous species of spider. It lives in Australia, North America, and is also found in Russia. The size of females reaches 1 cm, males are much smaller. The body of the black widow is black, and on the abdomen there is a characteristic red spot in the shape of an hourglass. Males are brown with white stripes. The bite is deadly.

Karakurt (lat. Latrodectus tredecimguttatus)- this look is deadly poisonous spiders from a family of black widows. The female karakurt has a size of 10-20 mm, the male is much smaller and has a size of 4-7 mm. There are 13 red spots on the abdomen of this scary spider. In some varieties, the spots have borders. Some mature individuals are devoid of spots and have a completely black shiny body. Lives in Kyrgyzstan, in the Astrakhan region, in the countries Central Asia, in the south of Russia, Ukraine, in the Black Sea and Azov regions, in the south of Europe, in North Africa. Karakurt was also seen in Saratov region, Volgograd region, Orenburg region, Kurgan region, in the south of the Urals.

Spiders live everywhere and are found in all corners globe. They do not live only in areas where the surface of the earth all year round hidden under an ice shell. The number of species in countries with humid and hot climates is greater than in temperate or cold ones. With the exception of a few species, spiders are ground dwellers and live in built nests or burrows, being active at night.

Tarantula spiders and other species of mygalomorph spiders live in the crowns of equatorial trees and shrubs. “Drought-resistant” species of spiders prefer burrows, ground crevices and any shelter at ground level. For example, digger spiders (atypical tarantulas) live in colonies, settled in individual burrows located at a depth of up to 50 cm. Some species of mygalomorphic spiders close their burrows with special flaps made of soil, vegetation and silk.

Sidewalk spiders (crab spiders) most They spend their lives sitting on flowers waiting for prey, although some members of the family can be found on the bark of trees or the forest floor.

Representatives of the family of funnel-web spiders place their webs on tall grass and bush branches.

Wolf spiders prefer damp, grassy meadows and swampy wooded areas, where they are found in abundance among fallen leaves.

The water (silver) spider builds a nest underwater, attaching it to various bottom objects with the help of webs. He fills his nest with oxygen and uses it as a diving bell.

What do spiders eat?

Spiders are quite original creatures that eat very interestingly. Some types of spiders may not eat for a long time - from a week to a month or even a year, but if they start, there will be little left. Interestingly, the weight of food that all spiders can eat during the year is several times greater than the weight of the entire population living on the planet today.
How and what do spiders eat? Depending on the species and size, spiders forage and eat differently. Some spiders weave webs, thereby organizing clever traps that are very difficult for insects to notice. Digestive juice is injected into the caught prey, corroding it from the inside. After some time, the “hunter” draws the resulting “cocktail” into his stomach. Other spiders, while hunting, “spit” sticky saliva, thereby attracting prey to themselves. Beetles and Orthoptera, and some species are able to drag an earthworm into their home and calmly eat them there.
The queen spider hunts only at night, creating a sticky web bait for unwary moths. Noticing an insect next to the bait, the queen spinner quickly swings the thread with her paws, thereby attracting the attention of the prey. The moth happily hovers around such a bait, and having touched it, it immediately remains hanging on it. As a result, the spider can calmly attract it to itself and enjoy its prey.

Large tropical tarantula spiders happily hunt small frogs

Aquatic species of spiders get their food from the water, using their webs to catch tadpoles, small fish or midges floating on the surface of the water. Some spiders, which are predators, due to the lack of victims, can also get enough of plant food, which includes pollen or plant leaves. Haymaking spiders prefer cereal grains.

Judging by numerous notes by scientists, a huge number of spiders destroy small rodents and insects several times more than the animals living on the planet.

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How does a spider weave a web?

In the back of the spider's abdomen there are from 1 to 4 pairs of arachnoid glands (arachnoid warts), from which a thin thread of web stands out. This is a special secret, which today many call liquid silk. Coming out of thin spinning tubes, it hardens in air, and the resulting thread turns out to be so thin that it is quite difficult to see with the naked eye.

In order to weave a web, the spider spreads its spinning organs, and then waits for a light breeze so that the spun web catches on a nearby support. After this happens, he moves along the newly created bridge with his back down and begins to weave a radial thread. When the base is created, the spider moves in a circle, weaving thin transverse threads into its “product”, which are quite sticky.

It is worth noting that spiders are quite economical creatures, so they absorb damaged or old webs, after which they reuse them. And the web becomes old very quickly, since the spider weaves it almost every day.

Spiders are all around us. Therefore, it is important to know which spiders are safe and which ones you need to avoid.

Spiders are one of the the oldest inhabitants planets known from the Devonian and Carboniferous periods. It is believed that they appeared approximately 400 million years ago. Creatures Paleozoic era had a characteristic arachnoid apparatus, but were more primitive. Their habitat is the widest - the entire planet, not counting Antarctica.

Spider Science: What is it called?

Araneology is the science of spiders, which is part of the branch of zoology - arachnology. Arachnology studies arthropod invertebrate arachnids. The origin of the name is ancient Greek.

Also, arachnology is the art of weather prediction based on observing the actions of spiders.

Spiders - what are they: types

Researchers know about 42 thousand species of spiders. Spiders can be divided into three large suborders, which differ mainly in the structure of the jaws, or more precisely, in the position of the chelicerae relative to the longitudinal axis of the body.

Suborder Orthognatha

More often, representatives of this suborder are called migalomorphs. They are characterized by the presence of thick hairs, large sizes and a primitive structure of the jaws - the claw is directed downwards and grows only on the upper jaw. Respiratory system presented lung sacs.

The majority of mygalomorphs live in warm climates. They make burrows underground.

Orthognatha includes:

• tarantula spiders
• funnel spiders
• ctenizidae
• digger spiders

Suborder Araneomorpha

Almost all other species of spiders known to naturalists belong to the large group Labidognatha or Araneomorpha. They differ in that both jaws are equipped with claws. The respiratory system is represented by the trachea.

Types of spiders that catch prey without a net:

• crab spiders
• jumping spiders
• wolf spiders

Types of spiders using a trapping net:

• linifid spiders
• web spiders
• funnel spiders, or house spiders
• long-legged spiders
• orb weaving spiders

Among araneomorphic spiders, there are also those that are not capable of producing cribellum - a substance from which spiders produce durable spider silk, and those who produce it.

Suborder Mesothelae

Lyphistiomorphic spiders are distinguished by the fact that the chelicerae are spread out to the side rather than pointing downwards. This position is considered more evolutionarily advanced. But this suborder is considered the most primitive; traces of it were found in Carboniferous deposits. Spiders have archaic pulmonary sacs and four pairs of arachnoid warts, which have not yet been moved to the end of the abdomen. They live in earthen burrows that are closed with a lid. Signal threads radiate from the minks. Although one species prefers caves, where it makes web tubes on the walls.

These include:

• arthropod spiders
• primitive arthrolycosid spiders
• primitive arthromigalid spiders

Spider: insect, animal or not?

Spiders belong to a type of animal - the order arthropods in the class arachnids. Therefore, spiders are animals, not insects.

Differences between a spider and an insect:

• a spider has four pairs of legs, and insects have three pairs
• Spiders do not have antennae characteristic of insects.
• many eyes, up to twelve pairs
• the body of a spider always consists of a cephalothorax and abdomen
• Some types of spiders have intelligence: they distinguish strangers from their own, can protect the owner, sense the owner’s mood, and even dance to music. No insect can do this, unlike an animal.

Spider body structure

The body of spiders, covered with chitin as an exoskeleton, consists of two sections that are connected by a small tube:

• The cephalothorax is formed by the head fused with the chest
• abdomen

Cephalothorax

• The cephalothorax is divided by a groove into two sections: the cephalic and thoracic. In the anterior head section there are eyes and jaws - chelicerae. In most spiders, the chelicerae are directed downwards and end in a claw. The claws contain poisonous glands.
• The lower part of the jaws - pedipalps, are used as palps and grasping elements. Between the pedipalps there is a mouth used for sucking. In some mature males, the pedipalps are also the cymbium - the copulatory apparatus.
• Simple eyes are also located in the anterior cephalic region.
• Four pairs of jointed legs are also found on the cephalothorax in the thoracic region. Each spider leg consists of 7 segments. The last segment of each leg has two or more smooth or serrated claws.

Abdomen

• The abdomen can have the following shape: round, oval with processes, angular, elongated worm-shaped. On the abdomen there are stigmata - respiratory openings.
• On the underside of the abdomen there are arachnoid warts containing arachnoid glands. The genital opening is located near the base of the abdomen. In females it is surrounded by a thickened chitinous plate, and in males the genital opening looks like a simple slit.

Spiders can grow up to 10 cm in size, and the span of their limbs can exceed 25 cm, it all depends on the species. The smallest representatives are only 0.4 mm in size.

The color and pattern depend on the structure of the scales and hairs covering the body, the presence of pigment and the type of spider.

How many legs and limbs does a spider have?

• All spiders have four pairs of legs, which are located on the cephalothorax and are usually covered with hairs.
• Each foot has crescent-shaped, comb-like claws. Between the claws, most often, there is a sticky pad - a claw-like appendage.
• Spiders that weave webs have auxiliary serrated claws that allow the spider to move freely along the web.

How many eyes does a spider have?

• Depends on the species. Some species have only two eyes, and some have up to twelve. Most species have 8 eyes, which are arranged in two rows.
• In any case, the two front eyes are the main ones. They differ in structure from other lateral eyes: they have muscles to move the retina and do not have a reflective shell. The auxiliary eyes are also distinguished by the presence of light-sensitive retinal cells. The more of them, the sharper the spider’s vision.
• Some spiders can see as well as humans and distinguish colors. For example, jumping spiders. Night hunters, for example, side-walking spiders, see perfectly not only at night, but also during the day. But wandering spiders see best.

How does a spider weave a web?

The thread of the web consists of many thin threads, which the spider glues together with a special liquid that quickly hardens in air. Thanks to this, the strength of the web is achieved so high that spiders even travel with its help, covering kilometers of distance.

The web can be dry, sticky, elastic - it all depends on the purpose of the thread.

Types of threads for webs:

• for cocoon
• catching sticky thread
• for moving
• to entangle prey
• thread for fastening

The design of the web depends on the hunting method. When weaving, spiders use a thread that reflects ultraviolet rays, which most insects see. Moreover, the spider weaves ultraviolet-reflecting threads in such a way that they look like flowers, which also reflect ultraviolet. Therefore, insects fly to an alluring and sweet flower and end up in a web.

Stages of weaving a web:

1. The spider releases a long thread first. Such a thread is picked up by the air flow, rushes to the nearest branch and clings to it (Fig. 1, 2).
2. Then another free-hanging thread parallel to the previous one is woven. The spider moves to the middle of this thread, which is stretched under its weight, and weaves another thread in a downward direction until it finds a third support (Fig. 3).
3. The spider attaches a thread to the support and forms a Y-shaped frame.
4. Next comes the general contour and several more radii (Fig. 4).
5. An auxiliary spiral is woven at these radii (Fig. 5). This entire frame is woven from non-sticky thread.
6. Next, the spider weaves a second spiral with a sticky thread, towards the middle of the web from its edge.

Construction may take 1-2 hours.

How do spiders reproduce?

• Males usually differ from females in size (the male is smaller), long legs, brighter coloring, and the presence of pedipalps, which appear in males only during the last molt.
• First, males weave a special sperm web. Although some types are limited to a few stretched threads. Then the spider applies a drop of sperm to the web and fills the pedipalps with sperm, with the help of which it introduces sperm into the female’s seminal receptacle. And he goes in search of the female.
• The spider finds the female by smell. Having found a suitable female, the male begins to cautiously approach. If the female is not in the mood for courtship, she will attack the spider and may even eat it.
• If the female looks at the male favorably, then the male begins to lure the female: he performs “wedding dances”, “clangs” his legs, and brings prey. Having appeased the female, the spider carefully approaches her, touches her with the tips of her legs, then touches her with her pedipalps and retreats. The male also “drums” on the substrate.
• If the female does not show aggression and “drums” herself, then the male carefully approaches and brings his pedipalps to the female’s genital opening. The act lasts for several seconds.
• Then the male runs away so that the female does not eat him. Although this happens quite rarely. In one season, a female can have several males.
• After 6-10 weeks, the female weaves a cocoon into which she lays up to 500 eggs. The female carefully guards the cocoon, holding it between the chelicerae. After another 5 weeks, the spiderlings appear.

How long do regular spiders live?

Most spiders live for a year. But some species, such as Grammostola pulchra from tarantula spiders, can live 35 years. Moreover, this applies only to females; even male tarantulas live for 2-3 years.

Non-venomous spiders: list with names

There are no spiders that are not poisonous at all. Poison is necessary in order to paralyze the victim, for protection.

But the venom of most spiders found is not dangerous. In some cases, there is so little that no one will notice, or there will be redness and swelling. Although in isolated cases an allergy to spider venom is possible.

Safe for humansfrequently encounteredspiders:

Common harvest spider. The size of the male is up to 7 mm, the female is up to 9 mm. Long-legged. They hunt in the dark. They like to gather in a group so that they look like a clump of fur. Weaves a non-sticky web. They scare off enemies by releasing an unpleasant odor.

More than 5 thousand species. This small in size A 5-6 mm spider that loves to bask in the sun and is excellent at climbing glass. They are good jumpers, can jump up to 20 cm. They do not weave webs, they attack with a jump, and they have excellent eyesight.

More than 1 thousand species. Size up to 25 mm - females, up to 10 mm - males. On its abdomen there are several white spots forming a cross. They hunt using a round trapping net, which can reach 1.5 m in diameter.

Size up to 10 mm. It hunts from ambush, instantly grabs its prey and paralyzes it with poison. Doesn't weave networks. It has camouflage - if necessary, it changes color from rich yellow to white. Those that hunt on the bark of trees are brown in color, and those in the leaves are variegated.

House spider or funnel web spider, the most famous and widespread. The web weaves in a secluded place: on the ceiling, in the corner, behind the closet. The male is up to 10 mm in size, the female is slightly larger - up to 12 mm. The color is yellow-gray with brown spots.

The size of the female is up to 10 mm, the male is slightly smaller. The color is light yellow, sometimes greenish. On the underside of the elongated seed-shaped abdomen there are two light stripes. They build circular nets with large “holes” designed for long-legged mosquitoes. They build webs near water and are able to run on water.

The size of the male is up to 16 mm, the female is up to 12 mm. A rare spider, adapted to live in sluggish freshwater. Can swim. The abdomen is covered with hairs to retain air, so the spider appears “silver” under water. A “bell” filled with air weaves in the water, where it lives: rests, leaves reserves, eats caught prey.

Tarantula spider (tarantula). Large, up to 20 cm with a leg span. They have a beautiful variety of colors. Weaving a web. Some species are completely harmless to humans; the bite of others may cause swelling, redness, itching, heat, and muscle cramps. No deaths have been reported. They are the ones most often kept in houses; females of some species live up to 35 years. Very easy to care for. Birdeaters can even be trained.

Top 10 most dangerous, poisonous, deadly spiders in the world, on the planet: list with names

A resident of the tropics and subtropics of South America is the most dangerous spider according to the Guinness Book. The size of the spider is 10-12.5 cm. It is fast, active, does not weave webs, and constantly moves in search of prey. Loves bananas. It feeds on other spiders, insects, lizards, and birds.

When in danger, it rears up and shows its fangs. The poison is deadly for weakened people and children. Without assistance, death from the bite of some individuals can occur in 20-30 minutes. In an adult healthy person a severe allergic reaction usually occurs.

The habitat is the deserts of South America and Africa. They can go without water and food for a long time - up to a year. Size taking into account paw span up to 5cm.

When hunting, it buries itself in the sand, lets it get closer and attacks from cover. The poison is a hemolytic necrotic toxin that thins the blood and causes tissue decomposition. The victim dies from internal bleeding. No antidote has been created, but people die extremely rarely.

Habitat - Australia, within a radius of 100 km from Sydney. Size - up to 5 cm. Lives and hunts in stumps, under stones, on trees or open areas. The poison is not dangerous to most mammals, but is fatal to humans and primates.

When in danger, a spider rears up and shows its fangs. When biting, it digs into the victim's body and bites many times in a row. At the same time, it is difficult to tear it off. The poison is dangerous due to large doses. First, your health worsens: nausea, vomiting, sweating. Then the blood pressure decreases and blood circulation is disrupted, and in the end the respiratory organs fail.

One of the most famous species. Habitat: Mexico, USA, southern Canada, New Zealand. They prefer to live in the desert and prairies. The size of the female is up to 1 cm. Females are more dangerous than males. If bitten by a female, the antidote must be administered within 30 seconds.

Spider venom x 15 stronger than poison rattlesnake. The bite site takes up to 3 months to heal. The bite is characterized by acute pain, which after 1 hour spreads throughout the body, causing convulsions. Difficulty breathing, vomiting, sweating, headache, paresthesia of the limbs, fever.

Outwardly similar to a black widow. Originally lived in Australia, it has now spread throughout the world, with the exception of the poles. Up to 1 cm in size. It feeds on insects, flies, cockroaches, even lizards.

The poison is not capable of killing a person, but after a bite one feels pain, cramps, nausea, increased sweating, and general weakness.

6. Karakurt - “black worm”

From the family of black widows, it lives in the steppe and desert zones of Russia. The size of a male is up to 0.7 cm, a female is up to 2 cm. The most dangerous poison is in females that have red dots on their abdomen.

The spider bite itself is practically not noticeable, but after a few minutes you can feel it sharp pain, gradually spreading throughout the body. Convulsions begin, a red rash appears, the victim may feel causeless fear and depression. Without assistance, the bite can become fatal within 5 days.

The second name is violin spider. Habitat: northern Mexico, southern USA, California. The size of males is 0.6 cm, females are up to 20 cm. Not aggressive. Lives in dark, dry places: attics, sheds, closets.

The bite is practically insensitive. After a bite, the effect of the poison begins to be felt after it spreads throughout the body, within a day. The temperature rises, nausea, rash, pain throughout the body, and tissue swelling appear. In 30%, tissue necrosis begins, sometimes organs fail, and only a few deaths have been reported.

Initially, it inhabited only South America (Chile), now it also lives in North America and is found in Europe and Australia. Lives in abandoned places: barns, woodpiles, attics. It feeds on insects and other spiders. Size including paws - up to 4 cm.

The bite is painful, similar in strength to a cigarette burn. The poison has a necrotic effect. The victim feels severe pain. Kidney failure may develop. Treatment lasts many months, and 1 in 10 people die.

9. Wolf spiders

Habitat: the whole world, except Antarctica, but they prefer warm countries. They live in bushes, on grassy meadows, in forests near water sources, in fallen leaves, under stones. Dimensions - up to 30 mm. They feed on cicadas and bugs.

Bite tropical species can cause prolonged pain, dizziness, swelling, severe itching, nausea, and rapid pulse. Their poison is not lethal.

Theraphose Blond

10. Theraphose Blonde

One of the largest spiders, the second name is the goliath tarantula. Body size is up to 9 cm, leg span is up to 25 cm. It feeds on toads, mice, small birds and snakes. Bites only in cases of danger.

The poison has a paralytic effect. But for humans it is only fraught with swelling and itching. When biting large animals or humans, poison is usually not injected. When in danger, the tarantula shakes off sharp hairs from its back, which cause irritation of the mucous membranes.

Although there are many dangerous spiders, they rarely attack. Attack is usually associated with defense, and in ordinary life spiders stay away, preferring secluded places to live. There are few fatalities, but caution is always necessary when handling these animals.

Video. The strangest spiders and unusual spiders in the world

Krinitsyn Oleg

When I was little, I was very afraid of spiders - I ran away and hid from them. And when I grew up, I decided to learn more about them, so as not to be afraid, and maybe even make friends with these mysterious creatures.

In the summer I visited my grandmother in the village, I had the opportunity to watch the spiders. I even overcame my fear and began to pick them up and see how they would behave. It was very interesting. Adults knew a little about the life of spiders, so I began to look for material in books. I was able to learn a lot of interesting things about these amazing animals from encyclopedias. I was very interested to find out: how many types of spiders there are; what species are the spiders I observed; how they differ from each other; what do they eat; how they move along walls and ceilings. Also, I wanted to find an answer to the question: “Where do they get the web?” I also wanted to figure out why a spider is not an insect, because they are so similar. Many consider them disgusting, dangerous, disgusting. Therefore, I would like to change my opinion about spiders, tell adults and classmates why spiders are interesting and useful.

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Preview:

Department of Education

Administration of the municipality

Nadymsky district

Municipal educational institution

"Average comprehensive school № 6
with in-depth study of individual subjects" Nadym

Research

Krinitsyn Oleg,

2nd grade student.

Pedagogical supervisor:

Katyukova Olga Viktorovna,

primary school teacher.

Nadym

2013

		Page
	Introduction
	Main part
2.1.	Who are spiders?
2.2.	Why is a spider not an insect?
2.3.	Interesting facts about spiders
2.4.	Spiders I watched in the village this summer
2.4.1.	Spider - Haymaker
2.4.2.	Funnel Spiders
	Conclusion
	Bibliography

I.Introduction

Among the creatures living next to us, spiders are without a doubt the most interesting... Karl Frisch

When I was little, I was very afraid of spiders - I ran away and hid from them. And when I grew up, I decided to learn more about them, so as not to be afraid, and maybe even make friends with these mysterious creatures.

In the summer I visited my grandmother in the village, I had the opportunity to watch the spiders. I even overcame my fear and began to pick them up and see how they would behave. It was very interesting. Adults knew a little about the life of spiders, so I began to look for material in books. I was able to learn a lot of interesting things about these amazing animals from encyclopedias. I was very interested to find out: how many types of spiders there are; what species are the spiders I observed; how they differ from each other; what do they eat; how they move along walls and ceilings. Also, I wanted to find an answer to the question: “Where do they get the web?” I also wanted to figure out why a spider is not an insect, because they are so similar. Many consider them disgusting, dangerous, disgusting. Therefore, I would like to change my opinion about spiders, tell adults and classmates why spiders are interesting and useful.

Purpose of the study:study the external structure of spiders, find differences between spiders and insects, make sure that spiders are not insects.

Tasks:

• study the literature on the topic of the research work;
• compare spiders and insects;
• find out what spiders live in your grandmother’s house and garden;
• watch their lives
• present the work to the children.

Hypothesis: Spiders have no signs of insects, they are not insects

I have identified research paths and methods:

• studying sources of information;
• observation;
• conversation;
• analysis;
• practical work.

Object of study: spiders.

Subject of study: life of spiders.

II. Main part

2.1.Who are spiders?

From the encyclopedia I learned that spiders are the most large squad arachnids. Spiders (lat. Aranei ). There are 35,000 species described and this number must rise to approximately 50,000, since all spiders have not yet been studied.

Spiders appeared on Earth so long ago that it is even difficult to imagine (approximately three hundred and fifty million years ago), the ancestors of spiders first climbed onto land from the water in which the entire animal world lived in those distant times.

Spiders appeared a hundred million years earlier than flying insects, and when people appeared, spiders already felt like masters and looked like they do today.

Spiders are currently one of the thriving groups of animals. It is difficult to find a place in nature where spiders do not live. They have mastered all the natural zones of the Earth from deserts and tropical forests to the islands of Antarctica. Everest explorers found a spider at an altitude of 7,000 meters. Spiders survive where other animals die, for example, in highlands and caves. Spiders are very hardy and interesting animals.

All spiders are predators, but since they do not have good eyesight, they lie in wait for their prey. Spiders catch prey on their webs or by other means. Spiders that catch prey with webs are called web spiders. With the help of the hiletser, the spider injects poison into the victim. After several hours, the prey turns into a thick mass and the spider “drinks” it. Yes, yes, exactly “drinks.” Spiders eat only liquid food. They suck out the victim, leaving behind a dry shell. Even such giants as the bird spider “drink” their victims as if through a straw. Moreover, their menu includes not only insects, but even lizards and birds. Sometimes they eat each other.

However, there are spiders that do not use webs for hunting. They overtake prey by jumping, wait in ambush, etc. The hunter's victim can be: frogs, small rodents, insects...

Spiders, scorpions and ticks are similar to each other, so they are classified as arachnids. Spiders are close to insects in a number of ways, but clearly differ from them, and these groups are only very closely related. distant relationship.

2.2 Why a spider is not an insect

In order to figure out whether a spider is an insect or not, I decided to study and compare the structure of a spider with the structure of insects.

I learned that spiders have 2 body sections: the cephalothorax and abdomen. Spiders have 4 pairs of legs and pedipalps that are very similar to paws. The bases of the pedipalps are transformed into chewing organs.

Spiders have up to 8 simple eyes. Despite this a large number of organs of vision, many arachnids see very poorly. So bad that this distance is on average 30 cm.

Spiders do not have a skeleton inside their body. They have a hard outer shell called an "exoskeleton". As the spider grows, it needs to shed its old, tight shell. When molting, the spider climbs out of the old body and waits for its new, delicate skin to dry and harden. At the moment of molting, spiders are especially vulnerable.

At the end of the abdomen there are arachnoid warts. The substance coming out of them hardens and turns into threads of extraordinary strength.

Insects, Insecta - a class of creatures with the absence of vertebrae and the segmented structure of legs. They differ in body structure (divided into 3 sections - head, thorax and abdomen), one pair of antennae, 3 pairs of legs on the chest and mainly 2 pairs of wings. Some insects secrete various substances through special organs: cobwebs, silk, wax, poisons. The skin of insects is formed mainly from chitin, which forms a strong exoskeleton. The cavities are filled with the so-called fat body.

Insects have two eyes. They feed on plant and animal products. Insects in a colossal number of species inhabit the earth. They appeared in distant geological periods (starting from the Carboniferous). About 10,000 species are known in fossil form.

Thus, we can conclude: spiders are not insects. They belong to the class of arachnids, and differ from insects primarily in their body structure. The spider's body consists of a cephalothorax and abdomen, breathing is carried out by pulmonary sacs and trachea. In insects, the body is divided into the head, chest and abdomen, and they breathe exclusively through the trachea. In addition, the spider has 4 pairs of legs, while insects are arthropods that have 3 pairs of legs and 2 pairs of wings . Also, an insect can be distinguished from a spider by the presence of antennae, but spiders do not have antennae.

comparison table

“What is the difference between spiders and insects”

2.3 Interesting facts about spiders

It should be noted that spiders, especially tarantula spiders, have a certain amount of intelligence; they can even distinguish between their own and others. These spiders are often used as pets. They are also very subtle and sense the mood of their owner, and therefore you can even play with them, they are even able to protect their owner if he is in danger, and they can also dance to music.

Spiders of the species Cyclosa mulmeinensis from Singapore are able to make a copy of themselves from debris and remains of victims caught in the net. The dummy has “legs” and reflects light like its prototype, and a blow of wind can create the impression that it is moving. In this way, these spiders deceive the wasps that hunt them, since the dummy is located in the most visible place of the web, and in most cases, predators attack it, allowing the real spider to hide.

Spiders of the genus Cyclocosmia, living in Asia and North America, have an original appearance: their abdomen ends with a hard surface in the shape of a disk, on which numerous grooves form an intricate pattern. In the species Cyclocosmia truncata, for example, this pattern resembles a seal. When this spider is in danger, it crawls into its burrow and plugs the entrance with its disk, which coincides with the entrance hole in diameter.

Spiders of the Theridion grallator species, found only in the Hawaiian Islands, have an amazing body color that resembles a smiling human face, and the color of each individual is unique. Presumably, such a pattern should scare away their only enemies, birds.

It is possible to sew clothes from cobwebs, but it is several orders of magnitude more difficult and more expensive than from ordinary silk obtained from silkworms. The first documented mention of such clothing dates back to 1710, when the French scientist and entrepreneur de Seu Hilaire made gloves and socks from “spider silk” and presented them to the king. Louis XIV. And most recently at the American Museum natural history a piece of fabric measuring slightly larger than 3 was exhibited square meters. To obtain it, several dozen workers caught golden spiders in Madagascar for 4 years, then carefully removed the threads from them and released them back into nature.

The web has enormous strength potential. The thread made from their web, as thick as a pencil, can stop a Boeing at full speed. Ultralight and durable body armor using spider webs is currently being developed.

2.4 Spiders I watched in the village in summer

At my grandmother's in the village, I watched the hay spider and the funnel-web spiders.

2.4.1 Spider - Haymaker

Haymaker - we all know this amazing creature from the arachnid family with very long legs. If you grab a haymaker's leg, it will easily come off and twitch convulsively for many minutes. It is because of this movement, similar to the movement of a scythe, that the commonly known names “mow spider” or “haymaker” arose.

The haymaker's leg comes off so easily that it seems as if it is very loosely attached to the body. Actually this is not true. The throwing of the leg occurs voluntarily and depends on a special muscular movement. This phenomenon is called autotomy - self-mutilation. The autotomy of the legs in the haymaker, like the autotomy of the tail in lizards, serves for salvation from enemies. Approaching its prey, the predator first of all stumbles upon a palisade of limbs, and a torn off and twitching leg distracts it from the harvester running away on its remaining legs. Therefore, you can often find harvesters with an “incomplete” set of legs.

We will never see a haymaker weaving a web, making a lair for itself, or descending on a thin web thread - these arthropods do not have arachnoid warts.

You can meet haymakers on a tree trunk or on a fence, on the wall of a house or in cracks in the bark, under stones and in the litter in a forest, garden, park, field, or vegetable garden. Deciduous and mixed forests. In mountainous areas, these animals are found on rocks, in scattered stones and caves.

Haymakers go hunting at dusk or at night. They feed on insects, small spiders and other invertebrates.The biggest threat to spiders is the spiders themselves. In case of hunger strike, they even kill their offspring.

In my grandmother’s village, I was able to observe such a story. I put two haymakers in a plastic cup and fed them flies. But for some time I forgot about them and did not feed them, and two days later I discovered that there was one live spider in the glass - which was larger, and the other was eaten.

2.4 Funnel spiders

Perhaps one of the most famous spiders in Russia. He really loves to live in houses and households. buildings. Usually it weaves its network somewhere in a corner on the ceiling or behind a closet. In general, where the housewife’s broom cannot reach it. If he reaches it, the spider will not be upset: by the next morning he will mockingly build a new web in another corner. In the middle of the house spider's web there is always a funnel that leads into a small hole - its home. Here he sits and waits for prey - flying insects. As soon as someone touches the web, the owner jumps out from his hiding place and instantly deals with the troublemaker. There is usually a lot of dust in a person’s home, so very soon the web becomes dirty. It is his web that sticks to the ceiling and constantly sways.

The male grows up to 10 mm (not taking into account the length of the legs), the color is yellow-gray with brown spots. The female is larger, the color is the same as the male. Sometimes, if there is a lot of food, they grow to impressive sizes and at times crawl along the walls, scaring children and women.

The spider is timid and never attacks people. However, he can still bite if you accidentally crush him. However, the poison is not at all dangerous to humans and does not cause any visible consequences. The house spider is useful because it exterminates various insects that are harmful to people right in the apartment: flies, mosquitoes and various moths.

I also learned a very interesting fact: if you play musical instruments at home, the spider will come out of its hole to listen to you, or even begin to “dance” on its web. It turns out that the problem here is not at all the musical preferences of spiders. The music shakes the web like small insects, and the spider, in anticipation of dinner, comes out to check: “Who is shaking my web?” Finding no one, he is probably very surprised and watches for a while, puzzled. And then he even tries to “shake off” the invisible insect from the web.

Funnel spiders, by the way, react very sensitively to changes in temperature and humidity. Therefore, they can serve as a kind of living barometers. Previously, house spiders were completely trusted in such matters.

III. Conclusion

Some people are disgusted by the sight of spiders or afraid of them. This is often due to the fact that we know very little about these eight-legged animals. However, only a small number of spider species are dangerous to humans, and they do not live in Europe. Spiders are not insects, as many people think; they feed on them. Many spiders weave webs that trap their prey. And this makes spiders useful for people: they free us from flies, mosquitoes and other insects that often bother us. Without spiders, we would be stuck, so to speak, with insects.

While researching the life of spiders, I learned a lot of interesting things, read various literature about the life of animals and came to the following conclusion:

Spiders are not insects.

The life of spiders is very interesting.

They live near us different types spiders

The spider obtains its food using a web.

Spiders predict the weather, they are experts in weather changes.

Spider is man's friend!

From now on, I intend to study the life of these interesting animals even more deeply. And I will definitely share my knowledge and observations with my classmates, telling them about the amazing and diverse world spiders and their benefits for humans.

Bibliography

1. "Mysteries of the Wild"; Moscow "ROSMEN", 2004
2. “My first book about animals”; Moscow "ROSMEN", 2006
3. "Around the world"; A. Tikhonov, Moscow “Bustard plus” 2008 https://accounts.google.com
   

   Slide captions:

   Why is a spider not an insect? Of the creatures living next to us, spiders are, without a doubt, the most interesting... (Karl Frisch) Prepared by Oleg Krinitsyn

   Preface When I was little, I was very afraid of spiders - I ran away and hid from them. And when I grew up, I decided to learn more about them, so as not to be afraid, and maybe even make friends with these mysterious creatures. In the summer I visited my grandmother in the village, I had the opportunity to watch the spiders. I even overcame my fear and began to pick them up and see how they would behave.

   Who are spiders? Spiders appeared on Earth a very long time ago, approximately three hundred and fifty million years ago, earlier than flying insects, and when people appeared, spiders already felt like masters and looked the same as they do today. It is difficult to find a place in nature where spiders do not live. Spiders survive where other animals die, for example, in highlands and caves.

   Who are spiders? All spiders are predators, but since they do not have good eyesight, they lie in wait for their prey. Spiders catch prey on their webs. They inject poison into the victim. After several hours, the prey turns into a thick mass and the spider “drinks” it. Yes, yes, exactly “drinks.” Spiders eat only liquid food.

   Why is a spider not an insect? Spiders are close to insects in a number of ways. In order to figure out whether a spider is an insect or not, I decided to study and compare the structure of a spider with the structure of insects. The spider's body consists of a cephalothorax and abdomen, breathing is carried out by pulmonary sacs and trachea. In insects, the body is divided into the head, chest and abdomen, and they breathe exclusively through the trachea.

   Why is a spider not an insect? In addition, a spider has 4 pairs of legs, while insects are arthropods that have 3 pairs of legs and 2 pairs of wings. Spiders have up to 8 simple eyes. But despite this they see very poorly. This distance is on average 30 cm. Insects have two eyes. Also, an insect can be distinguished from a spider by the presence of antennae, but spiders do not have antennae. Thus, we can conclude: spiders are not insects.

   Interesting facts about spiders It is interesting that spiders, especially tarantula spiders, have a certain amount of intelligence; they can even distinguish between their own and others. These spiders are often used as pets. They also very subtly sense the mood of their owner, and therefore you can even play with them, they are even able to protect their owner if he is in danger.

   Interesting facts about spiders Spiders of the species Cyclosa mulmeinensis from Singapore can make a copy of themselves from debris caught in a net. In this way, these spiders deceive the wasps that hunt them.

   Interesting facts about spiders Spiders, found only in the Hawaiian Islands, have an amazing body color that resembles a smiling human face, and the color of each individual is unique. Presumably, such a pattern should scare away their only enemies, birds.

   Watching spiders At my grandmother's in the village, I watched the hay spider and the funnel-web spiders.

   Haymaker You can meet harvesters on a tree trunk or on a fence, on the wall of a house or in cracks in the bark, under stones. The harvestman never spins a web - they do not have spider warts. If you grab a haymaker by his long leg, it will easily come off and will twitch convulsively for many minutes. It is because of this movement, similar to the movement of a scythe, that the name “haymaker” arose.

   Haymaker Haymakers go hunting at dusk or at night. They feed on insects and small spiders. But sometimes they eat each other. In my grandmother’s village, I put two haymakers in a plastic glass and fed them flies. Then I forgot about them and didn’t feed them, and two days later I discovered that there was one live spider in the glass - which was larger, and the other one had been eaten.

   Funnel-web spider The funnel-web spider is one of the famous spiders in Russia. Likes to live in houses. Usually it weaves its network somewhere in a corner on the ceiling or behind a closet. In the middle of the web there is always a funnel that leads into a small hole - his home. If someone touches the web, the spider jumps out from its hiding place and instantly grabs the troublemaker.

   Video Feeding the Funnel Spider

   Conclusion The spider is timid and never attacks people. However, he can still bite if you accidentally crush him. However, the poison is not at all dangerous to humans and does not cause any visible consequences. The house spider is useful because it exterminates various insects that are harmful to people right in the apartment: flies, mosquitoes and various moths. Some people are disgusted by the sight of spiders or afraid of them. This is often due to the fact that we know very little about these eight-legged animals. While researching the life of spiders, I learned a lot of interesting things, and came to the main conclusion: The spider is a friend to man!

SPIDERS
(Aranei),
a detachment of the arachnid class, which also includes ticks, scorpions, harvestmen, etc. Spiders are close to insects in a number of ways, but clearly differ from them, and these groups are related only by a very distant relationship. A well-known characteristic feature of many spiders is the ability to weave complex trapping networks (nets) from a silk-like substance secreted by the arachnoid glands. Some spiders, such as the black weaver spider and tropical tarantulas, can inflict very painful bites that can lead to fatal, however, most spiders, although they bite, are not dangerous to humans. The name of the class Arachnoidea comes from the Greek. arachne - spider. IN ancient greek mythology Arachne was the name of a girl who was such a skilled weaver that, having challenged the patron goddess of this craft, the goddess Athena, to a competition, she wove a fabric better than her. The annoyed goddess turned her rival into a spider, declaring that from now on Arachne and her entire family would spin and weave until the end of time. In total, approx. 30,000 species of spiders. The length of their body ranges from 0.1 to 5 cm. The main food is the liquid tissue of insects, which spiders catch by rushing from ambush or using a web. Spiders are found at almost all inhabited latitudes and altitudes: they were found on the slopes of Everest 6700 m above sea level and caught (juveniles) 600 m from the surface of the earth. Some species live in water. While settling, juveniles of a number of small species climb onto the ends of blades of grass and other towering objects and, raising their abdomen, begin to secrete an arachnoid thread, which is picked up by the air flow and, having reached a sufficient length, carries the animal on itself. This type of summer occurs in certain seasons and is especially noticeable in the “Indian summer”, when in the air you can see entire “flying carpets” of dozens of intertwined cobwebs. This unique method of settlement allows spiders to travel vast distances and even reach islands lost in the ocean.

The web and the construction of nets. The ability to secrete arachnoid thread - characteristic feature almost all spiders. The material for it is formed in special glands located in the back of the abdomen, and the so-called spider warts. Some spiders produce threads of different (up to six) types and use each of them for very specific purposes. As the spider moves, it continuously secretes webs, which, like a climber's safety rope, it periodically attaches to the surfaces it passes over. That is why a disturbed spider can almost always cross its legs, fall from the support and, hanging on an extensible thread, descend along it to the ground. When prey gets into the net, the spider usually entwines it with a web and only then kills it with poisonous claws (chelicerae) and sucks it out. Probably the most interesting feature of spiders is the construction of trapping nets from their webs. Their forms are very diverse and often very beautiful. Not all spiders use their webs to catch insects, but each species weaves it in a specific way, and the resulting structure may well serve as a taxonomic character. The most beautiful, so-called Wheel-shaped, nets are built by orb-weaving spiders from the family of spiders (Araneidae). First the spider climbs onto high place, usually near a path or other open space, and secretes a very light thread, which is picked up by the breeze and, accidentally touching a neighboring branch or other support, is braided around it. The spider follows this thread to new point, along the way strengthening the web with an additional secretion. In a similar way, two or three more relatively thick “cables” are laid, making up a closed frame, inside which the catch structure itself will be located. Usually the webs are oriented more or less vertically, but some species of spiders build horizontal webs. Threads-radii are stretched between the sides of the frame, connecting in the center, like spokes in the hub of a wheel. Now, starting near this place, the spider moves towards the periphery in a spiral, leaving behind itself a thread attached to the radii, the distance between the turns of which is determined by the span of its limbs. While the web is not yet sticky, but having reached the outer frame, the spider again moves in a spiral, but with more densely spaced turns, back to the center, this time forming a thread, which, unlike the previous ones, is covered with droplets of sticky secretion. As this actual catching spiral is laid, the thread of the first non-sticky spiral is bitten off and thrown away. Obviously, she served only a kind of scaffolding. When the nets are ready, the spider moves to their center or to a shelter located next to the net and waits for any flying insect to stick to the web. Usually the entire structure works for one night, and by the morning it is torn apart in many places. One of the most beautiful webs is made by the common species Argiope aurantia, a large spider with a black and gold pattern on its body. Its extensive spicate nets are characterized by a zigzag thread running vertically through the center of the structure. The shape of the fishing net of other species is completely different. For example, in representatives of the genus Frontinella it resembles a cup on a saucer. Funnel web spiders (family Agelenidae) have a web similar to a net, and spiders of the family Gnaphosidae build tubular shelters from the web under stones and other objects, where they hide between hunting trips. An unusual wheel-shaped network of golden threads is built by the species Nephila clavipes. This large spider, common in the southern United States, is characterized by legs with tufts of hairs. The ability of spiders to secrete a thread resembling silk has repeatedly led to attempts to use them like silkworms, but these experiments were not successful. The main difficulty is that spiders must be fed with live insects, and to obtain one kilogram of fiber quickly enough requires more than 1.3 million spiders! At one time, crosshairs were made from cobwebs optical instruments, such as theodolites, levels and telescopes. Many spiders do not build webs at all and simply hunt prey from ambush. This is characteristic of representatives of such families as wolf spiders (Lycosidae), jumping spiders (Salticidae) and theraphosid tarantulas (Theraphosidae). Jumping spiders, for example, track victims using their keen vision and catch them in one jump.

WEAVING A NET WITH A SPIDER. From the middle of the upper thread, the spider descends on the web to the lower one. From the middle of this web, which is ultimately divided into two “radii,” he extends a third “radius,” the second end of which he attaches to the upper thread, and continues such movements toward and away from the center until he has installed all the “spokes” of the wheel-shaped network. He strengthens its “hub” with several spiral turns.

Variety of spiders. Orb-weaving spiders and spiders that do not build webs have already been mentioned above. Let's take a closer look at their different types.
Theraphosides. One of the most interesting American spiders is the species Dugesiella hentzi. This is a large animal, the leg span of which reaches 15 cm. The body color is dark brown, so in general the animal is, to put it mildly, unattractive. People tend to be afraid of it, but this spider is relatively harmless: its bite is no worse than a bee’s. It is common in the southwestern United States and leads more or less night look life. The main enemy of this species is a wasp from the genus Pepsis, the name of which is translated from English as “big blue tarantula hawk”. She paralyzes the spider with a sting and drags it into her burrow to feed the larva. The bites of some tropical theraphosids are very poisonous even to humans. Representatives of this family often live up to 20 years.
Ctenizidae. In some areas of the United States there are interesting spiders from the family Ctenizidae. They vary in size and reach a length of 2.5 cm; The color of the massive body is dark. These spiders dig holes in the ground and line their walls with cobwebs. A characteristic feature of such shelters is a tightly fitted door, which is very difficult to open when the spider is holding it from the inside. It has been established that in this case the animal can withstand a pulling force equal to almost a pound: for a person it is equivalent to 10 tons. From time to time, ctenisids leave their burrows to hunt. Their main enemy is a type of wasp that can open the door of their lair or attack spiders when they are outside.
True tarantulas (Aviculariidae). This family includes the largest spiders in the world, which even attack chicks in the tropics. The length of their body reaches 5 cm, and the span of their legs is 18 cm.
"Arcane" spiders. Representatives of the genus Mastophora use probably the most unusual method of catching prey. First, the spider stretches a strong thread of web between the branches, usually over a stream where small midges hover. Approximately in the middle of it he attaches a catching thread with a heavy sticky lump at the end and holds it with his front foot. When an insect flies nearby, it swings this thread like a lasso, trying to catch the victim.
Digger spiders. Representatives of the genus Atypus weave a dense tube with a diameter of approx. 2.5 cm, which comes out of their burrow and lies on the ground, usually under a tree, continuing for a distance of about 30 cm. The spider hides inside the tube and, when an unwary insect lands on it, grabs it right through the web wall.
Side-walking spiders (Thomisidae). These spiders are also called crab spiders for their external resemblance to the latter. They are medium in size, often brightly colored and usually hide in flowers, where they hunt insects that come for nectar, such as bees.
Water spiders. In the United States, relatively large spiders of the genus Dolomedes are common, which can run along the surface of standing bodies of water and even dive under water, holding on to plants. These spiders feed on insects, fish fry and tadpoles. The silverback spider lives in Europe, spending most of its life underwater in places where there is little or no current. This is probably the most unusual spider in the world, considering that it, like all representatives of its class, breathes atmospheric air. In the spring, it goes under water and stretches a horizontal network of cobwebs with very small cells between the plants. Then, rising to the surface, it exposes the end of the abdomen, covered with non-wettable hairs. Air collects between them, which the spider, in the form of a bubble held by its legs, drags into the depths and shakes off under its web. It does not allow the bubbles to float up and after repeated such flights it bends into a bell the size of a thimble or even larger, supported from the inside by an air chamber. The spider hides inside it, inaccessible to most enemies, immediately lays eggs, hatches young and overwinters. The bells of the male and female living separately are connected to each other by a bridge made of cobwebs.
Poisonous spiders. It's common to be afraid of spiders. Indeed, almost all of them are armed with poisonous claws, but only a few species are dangerous to humans. In the United States, you need to beware of two of them - the “brown recluse” (Loxosceles reclusa) and the “black widow” (Latrodectus mactans). The length of the first is only 0.6 cm. This spider lives in the Midwest, often in homes where it hides behind furniture. At the site of its painful bite, an ulcer forms, which may never completely heal. The black widow spider is found throughout most of the United States. The bite of this species causes severe pain and can lead to death due to the neurotoxin injected into the wound. The female's body is shiny black with bright red spots. There is usually a red hourglass pattern on the underside of the abdomen. The male is much smaller than the female, but similar in coloring. The name “black widow” is explained by the fact that the female often eats her partner after mating, which, however, is a fairly common phenomenon among spiders. This species is not aggressive, and spiders usually try to hide from humans, but if picked up, they often bite.
Spider structure.
External building. Spiders, unlike insects, do not have antennae (antennae) or jaws. The body is covered with an external skeleton (exoskeleton) and consists of two sections - the cephalothorax, formed by the fused head and chest, and the abdomen. They are connected to each other by a narrow stalk. At the anterior end of the cephalothorax are simple eyes, the location of which serves as an important classification feature. Most spiders have four pairs. The cephalothorax bears six pairs of limbs. At the front of the head are two downward, jaw-like chelicerae, each of which ends in a sharp claw. It opens the poisonous glands located in these limbs. The second pair are pedipalps, used as palps and grasping structures. In mature males, their ends are modified and are used for mating. Between the bases of the pedipalps there is a small oral opening. All spiders, unlike insects, have four rather than three pairs of walking legs. The last segment of each of them bears at least two claws, and in some species there are many more. The arachnoid glands open on the underside of the abdomen, usually with six arachnoid warts. In front of them are small breathing holes - spiracles, or stigmas.

Internal structure. Spiders feed on liquid tissues sucked from their victims, mainly insects. The digestive system of spiders consists of a specialized sucking stomach, another stomach with blind outgrowths and an intestine surrounded by a digestive gland ("liver") and opening at the end of the body with an anus. The circulatory system is not closed. It consists of the heart, arteries, veins and spaces (sinuses) between organs, washed by colorless blood (hemolymph). The heart is a pulsating tube with openings (ostia) that runs along the dorsal side of the body cavity. Unlike insects, it is not divided into several chambers. Spiders, as already mentioned, breathe air. Their respiratory organs are the trachea and lungs, called pulmonary books. Each such book consists of a bag, one of the walls of which is folded in the form of numerous leaf-shaped folds, reminiscent of pages. They exchange oxygen and carbon dioxide between blood and air. The lungs open to the outside with spiracles. The most primitive spiders have two pairs of pulmonary books; in more advanced ones, one or both of them are replaced by trachea piercing the body. Excretory system consists of a pair of coxal glands in the cephalothorax, etc. Malpighian vessels in the abdomen, which open into the intestine. Nervous system similar to that of insects. It consists of an abdominal trunk with branches extending to different organs and ganglia collected in the cephalothorax into a large subpharyngeal node, above which is the suprapharyngeal node - the “brain”. Sensory hairs are located on the pedipalps and walking legs. The reproductive organs are represented by ovaries in females and testes in males. Their openings are located below at the base of the abdomen.

INTERNAL STRUCTURE OF A SPIDER. Spiders are quite close to insects, but at the same time clearly differ from them. Their body is divided into two sections - the cephalothorax and abdomen. The cephalothorax bears six pairs of limbs: four pairs of walking legs, a pair of similar tactile pedipalps, which in males are modified to participate in mating, and a pair of chelicerae located in front of the mouth, armed with claws with ducts of poisonous glands located right there. The digestive tract of spiders passes over their largest ganglion (subpharyngeal) and the main nerve trunks. A special sucking stomach sucks out the liquid tissues of the victim. At the back it is connected to two blind gastric tubes, bent forward and reaching the poisonous glands; on the sides of these tubes four more pairs of blind processes extend to the bases of the walking legs. Digestive juice accumulates in them. The intestines pass through the abdomen, into which the ducts of thin digestive tubes flow, forming the “liver”. Excrement accumulates in the rectal (stercoral) sac and is expelled through the anus. The Malpighian vessels perform the function of the kidneys.

Reproduction. Fertilization in spiders is a very complex process. After mating, the female often eats the male. The eggs are laid in a web cocoon, which the female carries with her or attaches to a solid object, such as a plant. In some spiders, including the Argiope aurantia species mentioned above, these cocoons are clearly visible on trees, especially in winter after the leaves have fallen. Spiders hatched from eggs soon begin to weave their own trapping nets or disperse through the air, attaching themselves to flying cobwebs.
See also INSECTS.

Collier's Encyclopedia. - Open Society. 2000 .

The first spiders appeared about 400 million years ago. They descended from a crab-shaped ancestor. Today there are more than 40 thousand species of spiders.

Many people are sure that spiders are insects. In fact, spiders are a separate order and class - arachnids (Arachnida, subphylum Chelicerata - Chelicerata, phylum Arthropods). Noticeably different from insects.

First of all, it is worth noting that spiders have not 6 legs, but 8. In front there are special limbs with poisonous claws - chelicerae. However, in central Russia the presence of spiders that are deadly to people has not been registered. From a big bite
the spider can only be felt as a burning sensation, fever and pain. Spiders will not attack first. If a small spider accidentally falls from the web onto a person, you should carefully blow it away and not hit it - otherwise it may get scared and bite.

Spiders usually have three pairs of arachnoid warts on their abdomen. Digestion in these arthropods is extraintestinal. Unlike, for example, predatory mantises, which chew a caught fly with appetite, the spider injects digestive enzymes into it, transforming
the insect enters the “soup” after a few hours, after which it sucks out the contents. Spiders have very strong webs; if a plane hits a pencil-thin web, it will not break.

Spiders usually have 8 eyes, sometimes 6, or very rarely - 2. Males have bulbs on their forelimbs, into which he places sperm to fertilize the female. Some males are already prepared for death after mating - they allow the female to eat them, others intend to fight for their lives and try to escape. In any case, males do not live long, but females need to raise offspring, so they live longer. Males are smaller, females are huge. Many females are caring mothers. They weave a ball-cocoon from a web and carry spiderlings in it.

Almost all spiders are predators. An exception is the Kipling's bagheera spider (Bagheera kiplingi). Biologists discovered this jumping spider in the forests of Central America, on the branches of an acacia tree. Spiders live on acacia trees along with ants. Ants guard these trees for the nutritional Belt bodies (named after naturalist Thomas Belt), sweet shoots at the ends of the leaves of tropical acacia species. Spiders also feed on these formations.

The first thing that catches your eye when meeting insects is their long, constantly moving antennae. Spiders don't have antennas. Their eyes are also simpler, but there are many of them - most often eight. The body is covered by an external skeleton (exoskeleton). It consists of a cephalothorax and abdomen, connected to each other by a stalk.