Representatives of arachnids. Class arachnids Message on the topic arachnids

With their terrifying and not always pleasant appearance, spiders, despite their small size, evoke at least hostility in more than half of humanity. Meanwhile, there are those who keep them as pets, along with hamsters or parrots. Have you ever thought about how much we know about representatives of this part of the animal world? We encourage you to learn more about the class Arachnida, including 10 interesting facts about arachnids that will surprise and perhaps intrigue you.

The class unites a fairly large group of diverse and completely different arthropods. It includes three branches: scorpions, mites and spiders, with a total of 114 thousand species, including almost 2000 fossils. The second and third groups are the most numerous - 55 and 44 thousand representatives, respectively. The outdated name of the Arachnida class is Arachnids. It comes from the Greek language and, according to one version, is associated with Arachne, a skilled weaver. Proud, she declared that she was superior to Athena herself in her skill, and invited her to a competition. Along with her confession, she received the wrath of the goddess and was turned into a spider, doomed to forever weave and hang in her webs. Perhaps, it is with this story that we can safely begin all the interesting facts about arachnids.

Dimensions and structure

Representatives of the class are distributed everywhere, but are predominantly terrestrial inhabitants; there are also inhabitants of fresh water bodies, as well as one marine species. The sizes of these arthropods range from a few microns to tens of centimeters. In the structure, it is customary to distinguish two sections: the opisthosoma (abdomen) and the prosoma (cephalothorax), the limb-bearing chelicerae, walking legs and pedipalps. The body of all arachnids is covered with a thin cuticle made of chitin. Spiders and scorpions have specialized organs - a venom-producing apparatus, and the former also have a spinning apparatus. By type of nutrition, almost all arachnids are predators, and only a few species have adapted to plant foods.

And now we invite you to find out the most unusual and interesting facts about arachnids (Arachnids), namely about spiders, as the most famous and mysterious representatives of the class.

Fact No. 1: about sizes

We are used to seeing small spiders at home or on the street, but we don’t even think about the fact that somewhere in the tropical wilds of South America lives a species that is huge by class standards - this is Blonde’s Theraphosa (photo below), also known as the goliath tarantula. Body dimensions reach up to 10 cm, and with straightened legs up to 25-30 cm. It is capable of catching mice, frogs and toads, lizards and, according to some sources, small birds.

Fact #2: about the web

The web is a secret secreted from special glands, which quickly hardens in the air and takes on a shape familiar to all of us. Its chemical nature is protein, similar in composition to silk threads. This is what the Arachnida class is famous for. Interesting facts about the web are numerous. It is very thin and light, but at the same time durable. So, the mass of the web, which can weave the entire planet, will be only a little more than 300 grams.

But at the same time, if you imagine that it was woven from spider threads the thickness of an ordinary pencil, then it is capable of stopping a plane. The largest webs are weaved by nephiles. They are also known as and have a body size of up to 4 cm, and a leg span of up to 12 cm. The largest web in the world was recorded most recently in Mantadia (National Park) in Madagascar. The diameter of the “catching net” was 25 meters. Darwin's spider wove such a miracle. Having studied the characteristics of the web, scientists came to the conclusion that it is unique in strength and exceeds all similar indicators of other types by 10 times.

Fact #3: about reproduction

Among spiders, sexual dimorphism is clearly visible; females are larger (sometimes significantly) than males, and they also live longer. This is due to several factors. Firstly, the males of many species, after fertilizing the eggs, die themselves, and secondly, they can be killed by the female. Interesting facts about arthropods (Arachnids in this case) would be unthinkable without mentioning the notorious one (karakurt). Its venom is many times more toxic to humans than a rattlesnake. The name of the spider is due to the fact that after fertilization, in most cases, the female simply eats the male. The number of eggs laid can reach up to 20 thousand.

Fact #4: about poison

In 2010, the Guinness Book of Records recognized the genus of Brazilian wandering spiders as the most poisonous in terms of strength and number of species. Their habitat is limited to Central and South America. The genus includes, according to the latest data, eight species, and the last one was discovered quite recently - in 2001. Their venom contains a dangerous and powerful neurotoxin, which in toxic concentrations leads to uncontrolled muscle contraction and causes respiratory arrest. However, there is an effective antidote that reduces the number of deaths to a minimum.

Fact #5: about food

The method of feeding and diet largely depends on the species. So, some can fast from several days to a year. However, interesting facts about biology (Arachnids are meant in particular) will be incomplete without assumptions from the series: “What if?” So, even if some species are on hunger strike, in a year spiders eat a total biomass that exceeds the entire humanity in volume. That is, if they ate people, they could easily deal with us in three days.

Spiders are hunters, but they get their food in a variety of ways. For example, the spinning queen is fishing. Having tied two trees with a web, she lowers the loose thread with droplets of secretion at the end and observes. As soon as a potential victim appears, it begins to swing the “fishing rod”, thereby attracting attention. Moths and other insects, having stuck, no longer have a chance to free themselves, and the spider begins to quietly pull the thread back towards itself.

Fact #6: once again about food

Interesting facts about arachnids aren't just about how they hunt and eat. The spider does not always choose its victim; it often becomes the victim itself. The existence of edible specimens is known for certain, and you can even try them in the public domain. Asian cuisine is especially famous for the abundance of such exotics. And even in its habitats, the indigenous people (Cambodia, Laos) enjoy roasting it over the fire. Now, in many ways, this serves to attract curious tourists.

Fact #7: The spider is a vegetarian

When listing interesting facts about arachnids, it is impossible not to mention this representative of the class. Most spiders are predators. However, as you know, there are exceptions to all rules, in this case it is Kipling’s Bagheera. A small brightly colored spider (pictured) lives on acacia trees and feeds on vegetation.

It has been noted that in years of severe drought and lack of food supply, they can turn to cannibalism.

Fact #8: about hunting

Weaving a skillful web is not the destiny of all spiders. There are also those who use thin threads only as material for the construction of a dwelling, in which the female subsequently lays eggs. Jumping spiders are active daytime hunters and have keen eyesight. They have an interesting hydraulic system of the body, which allows, as a result of changes in blood pressure, to expand their limbs and jump long distances. It is noteworthy that before committing them, the spider takes precautions and attaches itself to the original place with a web thread. The photo below is a gray morph.

Fact No. 9: About life expectancy

It’s difficult to say unequivocally. It is only known that the minimum is before puberty and mating (from several months to a year). That is, the individual dies after fulfilling its purpose - procreation. However, interesting facts about arachnids should definitely include tarantulas. They are real record holders for life expectancy, although it directly depends on gender. Males die after the first mating. Females, on the other hand, can live for years and even decades. It was noted that in captivity, subject to all conditions of detention, some specimens reached the age of 30 years.

Fact #10: about Scorpios

These amazing creatures are perhaps the most ancient arthropods that once came out of the sea onto land (more than 400 million years ago), however, their size was then very impressive - up to 1 m in length. The current species are much more modest in size. The largest representative of the order is the imperial scorpion (up to 20 cm), the smallest is about 13 mm. They feed exclusively on live food, do not drink water, and can fast for two years. The most poisonous representative is the Israeli scorpion, which accounts for 90% of all people killed by the bite of these arthropods in North Africa.

These very dangerous scorpions complete the top 10 amazing information about this class of arthropods. However, this is not the entire list, because nature still leaves many mysteries and secrets for humans.

1. General characteristics of the class of arachnids.

Arachnids were the first arthropods to populate land and adapt to various terrestrial living conditions. During evolution they diverged into many different forms. This class includes scorpions, harvestmen, spiders, ticks, etc. In their external structure, arachnids are characterized by the presence of a fused cephalothorax and a dismembered or fused abdomen. The head lacks antennae and compound eyes (there may be several simple ocelli). There are six pairs of limbs on the cephalothorax. The first two pairs (chelicerae and pedipalps) are highly modified and are involved in capturing, holding and killing prey. The remaining four pairs are walking legs. The abdominal limbs are reduced or modified into lungs and arachnoid warts. Respiratory organs - lungs, modified gill legs of ancient ancestors, trachea, or both at the same time. The excretory organs are represented by Malpighian vessels. In the nervous system, the suprapharyngeal node (brain) reaches great development. The number of nerve nodes depends on the degree of dismemberment of the body. The digestive system consists of three sections, but the structure of the intestines varies depending on the type of diet. The most complex digestive system is in predatory arachnids with extraintestinal digestion. The degree of development of the circulatory system depends on the structure of the respiratory organs and the size of the animal. In small forms, the circulatory system may be absent. Arachnids have separate sexes. In connection with reaching land, external fertilization is replaced by external-internal fertilization. Development is direct (except for mites).

2. Diversity and practical importance of arachnids.

The order of spiders includes the very poisonous karakurts, which live in steppes and deserts, as well as tarantulas, which are found in the dry steppes of southern Europe, Kazakhstan and Central Asia. Many spiders provide benefits by exterminating harmful insects. Many small mammals, birds, lizards, frogs, and predatory insects feed on spiders. Material from the site

Arachnids include mites, most of which have a body that is not divided into segments (the cephalothorax and abdomen are fused). These are blood-sucking ticks - the hedgehog tick and the dog tick, which often attack humans. Their oral apparatus is very modified and serves to pierce the host’s skin and feed it with blood. A stuck tick is very difficult to remove. However, the main danger is that dog and taiga ticks are carriers of pathogens of dangerous diseases: taiga encephalitis, typhus, tularemia. In addition, among the mites there are causative agents of human diseases such as scabies (itch). A large group consists of saprophagous soil mites. By feeding on rotting residues, they help increase soil fertility.

The development of mites occurs with metamorphosis. A six-legged larva emerges from the egg and develops into an eight-legged nymph, followed by the adult tick stage.

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Cross spider - one of the most common types of arachnids. The female is large, up to 2 - 2.5 cm in size, the male - up to 1 cm. There is a cross-shaped pattern on the dorsal side of the abdomen.

Many species of spiders produce potent venom. The poison has a very strong general effect karakurt , which is found in the desert and steppe zones in Central Asia, the Caucasus and Crimea.

Karakurt is a medium-sized spider (female - 10 - 20 mm, male 4 - 7 mm), black with red dots on the abdomen. Favorite habitats are virgin wormwood, wastelands, and ravine slopes. The female makes a lair in depressions in the soil, often in rodent burrows, stretching trapping nets at the entrance. The eggs overwinter in cocoons, which are suspended in groups of two or four in the lair. The young emerge in April and are carried on the web by the wind. By June, spiders become sexually mature. With the onset of heat, females and males migrate, looking for protected places where they set up temporary networks for mating. After this, the females wander again in search of places to build a permanent lair, where they place cocoons. The number of karakurt bites of people and animals increases just during the periods of migration of females (June and July). Karakurt is very prolific, and periodically (every 10 - 12 or 25 years) outbreaks of its mass reproduction are observed.

Mature females are the most poisonous. The poison of the karakurt is 15 times stronger than the poison of one of the most terrible snakes - the rattlesnake. At the site of the bite, a small red spot is visible, which quickly disappears. After 10–15 minutes, a sharp pain spreads to the abdomen, lower back and chest, and the legs go numb. Strong mental agitation occurs, the bitten person experiences fear of death. Dizziness, headache, suffocation, convulsions, and vomiting are often observed. Characterized by blueness of the face, slow and arrhythmia of the pulse, the appearance of protein and blood in the urine. Then the patient becomes lethargic, but behaves restlessly, severe pain deprives him of sleep. After 3–5 days, a characteristic rash appears on the skin and the condition improves. Recovery occurs after 2–3 weeks, but weakness usually remains for more than a month. In severe cases, in the absence of medical care, death occurs within a day or two after the bite.

The most effective treatment is antikarakurt serum. After intramuscular injection of 5–10 cm 3 of serum, the patient’s suffering subsides, and after 3–4 days he recovers.

P.I. Marikovsky suggested cauterizing the bitten area with a flammable match head, but always no later than two minutes after the bite. When heated, the poison that has not had time to be absorbed is destroyed. This method is indispensable in the remote steppe, far from medical care.

Livestock suffer greatly from karakurt bites, camels and horses are especially sensitive, and usually die.

Of our other spiders, only a few are capable of biting through human skin. Among them is poisonous South Russian tarantula , common in the south. However, its bite cannot be compared with the bite of a karakurt. Females of the large tarantula race are most poisonous at the end of summer. Local painful phenomena similar to stings by large wasps are usually noted, but it has now been established that tarantula venom can also have a general effect,

causing a person to become febrile.

The largest spider - tarantula spider . Its length reaches 10 -15 cm, and it is capable of attacking small birds and rodents.

Scorpios - the oldest order not only among arachnids, but also among terrestrial arthropods. About 700 species of scorpions are known. These are medium-sized, 5–10 cm in shape, some large, predators (up to 15 cm long), resembling crayfish in appearance and having a claw-like second pair of mouth limbs. The abdomen is elongated and mobile; ends with a swollen tail segment, it contains a poisonous gland, the duct of which opens at the end of a curved sharp sting. In a threat pose, the scorpion raises it above its head and plunges a poisonous needle located at the end of the last segment of the abdomen into the body of the victim, holding it with its claws. The scutes of the trunk and segments of the limbs are formed by a very hard cuticle, often with a ribbed or tuberculate sculpture.

Scorpions live in countries with warm or hot climates, and are found in a wide variety of habitats, from rain forests to barren rocky areas and sandy deserts. Some species are found in the mountains at an altitude of 3 - 4 thousand meters above sea level. All of them are active at night, and during the day they hide in shelters, under stones, under loose bark, in the burrows of other animals, or burrow into the soil. Most species are thermophilic.

Scorpions are mostly viviparous; some species lay eggs in which the embryos are already developed, so that the young hatch soon. This phenomenon is called ovoviviparity.

The scorpion sting is a means of attack and defense. On small invertebrates that usually serve as food for the scorpion, the poison acts almost instantly: the animal immediately stops moving. For small mammals, scorpion venom is mostly fatal. The toxicity of different types of scorpions varies. For humans, a scorpion sting is usually not fatal, but there are a number of cases with very serious consequences, even death, especially in children and in hot climates. When the injection occurs, pain and swelling appear, then drowsiness, chills, and sometimes a temperature reaction occur. Usually these phenomena pass in a day or two, but they can drag on.

By feeding on insects, spiders and scorpions reduce the number of pests. They themselves, in turn, serve as food for small lizards, birds and mammals.

Many types of ticks are vectors causative agents of various human and animal diseases. Such diseases are called transmissible. The doctrine of vector-borne diseases was created by Russian academician B. N. Pavlovsky. He and his employees in the late 30s of the XX century. it was revealed that the occurrence taiga encephalitis in the spring-summer period is associated with the transmission of the virus that causes the disease by the taiga tick during blood-sucking of a person.

General characteristics of the class. The class includes land animals, with the exception of some groups that secondarily switched to living in water. Representatives of the class are spiders, harvestmen, scorpions, ticks, etc.

In arachnids, the upper layer of the chitinized cuticle contains wax-like and fat-like substances that sharply reduce moisture loss by the body. The body of arachnids is most often dismembered on the cephalothorax, load-bearing limbs, and a legless abdomen. There are no antennae. There are six pairs of limbs on the cephalothorax, of which two pairs are oral limbs, most often involved in food capture. First pair - chelicerae - have the form of claws (in scorpions, harvestmen), hooks (in spiders) or cutting stylets (in ticks). In many arachnids, a venom gland duct opens at the top of the chelicerae. The second pair is articulated palpi. The remaining four pairs are typical walking limbs with claws at the end. There are no limbs on the abdomen. In some arachnids, homologues of the abdominal limbs are spider warts. In spiders, they are located on the sides of the anus in the form of three pairs of tubercles, penetrated by numerous tubular ducts that extend from various types of arachnoid glands of the abdomen. The one they highlight cobweb - a protein liquid that solidifies in air in the form of thin threads.

Arachnids - predominantly predatory animals. Most of them tend to extraintestinal digestion. With the help of the secretion of the poisonous gland, they kill prey, and then they also inject the secretions of the digestive glands into the victim’s body. Then they absorb liquid semi-digested food with a muscular pharynx, which acts like a pump.

Respiratory organs in arachnids -lung sacs(in Scorpios) trachea(in ticks and harvestmen) or both together (in spiders). Lungs They are leaf-shaped folds, reminiscent of the pages of a book, into the cavity of which hemolymph enters, and gas exchange occurs through their thin chitinous wall. Trachea- These are thin cuticular branched tubes that protrude into the body cavity and are in close proximity to various organs. Gas exchange directly occurs through their walls.

Excretory organs - Malpighian vessels.

The sense organs are varied: simple eyes, organs of smell, taste, touch, chemical sense, etc.

All arachnids are dioecious. Fertilization is internal, development is direct (except for mites that have a larval stage).

Of great importance in the life of spiders is web. By weaving web threads with the help of comb-like claws into a strong web, spiders use it to build shelters and trapping nets, an egg cocoon, and also shelter fragile juveniles in it. On the warm days of Indian summer, young spiders settle on spider webs.

The diversity and importance of arachnids. Cross spider- one of the most common types of arachnids (Fig. 11.13). The female is large, up to 2-2.5 cm in size, the male - up to 1 cm. There is a cross-shaped pattern on the dorsal side of the abdomen.

Many species of spiders produce potent venom. Yes, bite karakurt dangerous for humans, horses, and cattle. Bite tarantula very painful and can cause a person to feel feverish. The largest spider - tarantula spider. Its length reaches 15 cm, and it is capable of attacking small birds and rodents.

Scorpios- large predators (up to 15 cm long), resembling crayfish in appearance and having a claw-like second pair of oral limbs. The abdomen is elongated and mobile. In a threat pose, the scorpion raises it above its head and plunges a poisonous needle located at the end of the last segment of the abdomen into the body of the victim, holding it with its claws. By feeding on insects, spiders and scorpions reduce the number of pests. They themselves, in turn, serve as food for small lizards, birds and mammals.

Rice. 11.13. Diagram of the internal structure of a spider: 1 - legs; 2 - eyes; 3 — stomach; 4 — heart; 5 — artery; 6 — ovary; 7—lung; 8—walking limbs; 9 — brain; 10 — mouth opening; II — poison gland; 12 - chelicerae.

Many types of ticks are vectors causative agents of various human and animal diseases. Such diseases are called transmissible. The doctrine of vector-borne diseases was created by Russian academician E. N. Pavlovsky. He and his employees in the late 30s of the XX century. it was revealed that the occurrence taiga encephalitis in the spring-summer period is associated with the transmission of the virus that causes the disease by the taiga tick during blood-sucking of a person.

In Belarus dog tick carries the Western tick-borne encephalitis virus.

Spider (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 of the 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 the structural structure of the integument 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 (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 on the African continent. Despite belonging to tarantulas, this type of spider does not bite, but only throws 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 (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. The species of flower spiders is distributed throughout European territory (excluding Iceland), and is 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 butterflies and bees caught in its “embraces”.

• Grammostola pulchra (Grammostola Pulchra)

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

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 “spit” sticky saliva while hunting, thereby attracting prey to themselves.

The main diet of spiders is insects. Small spiders happily eat flies, mosquitoes, crickets, butterflies, mealworms, cockroaches, and grasshoppers. Spiders that live on the surface of the soil or in burrows eat beetles and orthoptera, and some species are able to drag a snail or earthworm into their home and quietly 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, lizards, other spiders, mice, including bats, as well as small birds.

And this type of spider, such as the Brazilian tarantula, can easily hunt small snakes and grass snakes.

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.

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.

Types of web

There are several types of webs, differing in shape:

• The orb web is the most common type, with the minimum number of threads. Thanks to this weaving, it turns out to be unnoticeable, but not always elastic enough. From the center of such a web radial threads-webs diverge, connected by spirals with a sticky base. Typically, round spider webs are not very large, but tropical tree spiders are capable of weaving similar traps that reach two meters in diameter.

• Cone-shaped web: This type of web is made by the funnel-web spider. Usually it creates its hunting funnel in tall grass, while it itself hides in its narrow base, waiting for prey.

• The zigzag web is its “author”, a spider from the genus Argiope.

• Spiders from the family Dinopidae spinosa weave a web directly between their limbs, and then simply throw it onto an approaching victim.

• Spider Bolas ( Mastophora cornigera) weaves a thread of web on which there is a sticky ball with a diameter of 2.5 mm. With this ball, impregnated with female moth pheromones, the spider attracts prey - a moth. The victim falls for the bait, flies closer to it and sticks to the ball. After which the spider calmly pulls the victim towards itself.

• Darwin's spiders ( Caerostris darwini), living on the island of Madagascar, weave giant webs, the area of ​​which ranges from 900 to 28,000 square meters. cm.

The web can be divided according to the principle of responsibility of its weaving and type:

• household - from such webs spiders make cocoons and so-called doors for their homes;
• strong - spiders use it to weave nets, with the help of which the main hunt will be carried out;
• sticky - it is used only for preparing jumpers in fishing nets and sticks so strongly when touched that it is very difficult to remove.

Spider Reproduction

As spiders grow, from time to time they shed their tight chitinous shell and acquire a new one. They can molt up to 10 times in their entire life. Spiders are dioecious, with the female being much larger than the male. During the mating season, which lasts from mid-autumn to early spring, the male fills the bulbs located at the ends of his pedipalps with sperm and goes in search of a female. After performing the “mating dance” and fertilization, the male spider hastily retreats and dies after some time.

After two and a half months, the female spider lays eggs, and after 35 days small spiderlings appear, living in the web until the first molt. Females reach sexual maturity at 3-5 years of age.

Among spiders, only poisonous ones pose a danger to humans. In the CIS countries there is one such species - the karakurt, or black widow.

With a timely injection of a special serum, the bite goes away without consequences.

Recently it has become fashionable to keep spiders at home. For beginners, we recommend the white-haired tarantula spider, which is a harmless representative of the arachnid class.

• According to statistics, 6% of the world's population suffers from arachnophobia - the fear of spiders. Particularly sensitive people panic when they see a spider in a photo or on TV.
• Frightening-looking tarantula spiders, with a paw span of up to 17 cm, are actually calm and non-aggressive, thanks to which they have earned the reputation of popular pets. However, owners must protect their pets from stress, otherwise the spider sheds its bright hairs, which cause an allergic reaction in humans.
• The most poisonous spiders are considered to be black widows, their variety is karakurt, as well as Brazilian soldier spiders. The venom of these spiders, containing powerful neurotoxins, instantly attacks the victim's lymphatic system, which in most cases leads to cardiac arrest.
• Many people mistakenly believe that tarantula venom is fatal to humans. In reality, a tarantura bite causes only a slight swelling, similar to a wasp sting.
• Wall crab spiders, named Selenopidae in Latin after the Greek goddess of the Moon, move sideways as well as backwards.
• Jumping spiders are excellent jumpers, especially over long distances. As a safety net, the spider attaches a silk web thread to the landing site. In addition, this type of spider can climb glass.
• When chasing prey, some species of spiders can run almost 2 km in 1 hour without stopping.
• Fishing spiders have the ability to glide across water like water striders.
• Most species of spiders have an individual form of woven web. House (funnel) spiders weave webs in the shape of a funnel; dictine weaver spiders are characterized by angular webs. The web of Nicodam spiders looks like a sheet of paper.
• Lynx spiders are distinguished by a property that is uncharacteristic of spiders: to protect the clutch, females spit on the threat of poison, although this poison does not pose a danger to humans.
• Female wolf spiders are very caring mothers. Until the children gain independence, the mother “carries” the cubs on herself. Sometimes there are so many spiders that only its 8 eyes remain open on the spider’s body.
• The New Zealand cellar spider was immortalized in cinema thanks to director Peter Jackson, who used this species as the prototype for the spider Shelob.
• Very beautiful flower spiders lie in wait for prey on flowers, and adult females, as a camouflage, change their color depending on the color of the petals.
• The history of mankind is closely intertwined with the image of the spider, which is reflected in many cultures, mythology and art. Each nation has its own traditions, legends and signs associated with spiders. Spiders are even mentioned in the Bible.
• In symbolism, the spider personifies deceit and immeasurable patience, and the spider’s venom is considered a curse that brings misfortune and death.