Spiders represent a whole order of predatory animals that eat exclusively living organisms. As a rule, spiders catch these insects on their own. At the same time, they are not interested in inanimate objects.
Interesting to know! Scientists know about more than 42 thousand species of these animals living on our planet. Although no one knows the exact number. There are still plenty of unexplored places on our planet, and new species of small living organisms are discovered almost every day. In addition, spiders are excellent at camouflage.
All varieties of arthropods have differences from each other in their size, in the size of their paws, in the shape and size of the chelicerae, as well as in the degree of toxicity. The spider's body can be smooth or covered with bristles of varying lengths. At the same time, spiders can form webs or live in burrows, but all of them have main characteristics that allow them to be classified as arachnids.
General signs
As a rule, an ordinary spider has 6 pairs of limbs, but a person can notice only 4 pairs, since the organs of nutrition and touch are formed from the first 2 of them. The animal's body has 2 sections - the cephalothorax and abdomen, which are connected to each other by a thin bridge. If you carefully examine the spider, you will find that the cephalothorax also has a certain division into the chest and head parts using a thin groove. Limbs grow on the chest part, due to which the animal moves and weaves a web.
Interesting fact! Classic spiders always have a spinning organ.
On the head of the spider there are:
- Chelicerae formed by the first pair of limbs.
- Pedipalps formed from the second pair of limbs. They serve for the spider both as an organ of touch and as a tool for catching and holding insects.
- Eyes.
- Oral apparatus.
The majority of species have 8 eyes, although the number of eyes depends on the habitat. So, spiders that live in caves where the sun's rays do not reach do not have eyes as such.
Interesting to know! Oddly enough, the reproductive organs of spiders are also located on the pedipalps.
The internal structure of the body of spiders
Spiders are distinguished by the fact that they do not have a full-fledged circulatory system, as well as no blood, which is replaced by lymph. There is a heart, but a peculiar one, consisting of 3 or 4 holes, called awns. Through these openings, lymph enters the heart area, after which it is distributed throughout the body into the spaces between the internal organs. After this, the lymph enters the pericardial region of the body and is sent back to the heart. With the help of lymph, the spider receives the necessary portion of oxygen.
The spider's respiratory organ also has a unique structure. The respiratory system consists of plate-shaped pulmonary sacs that resemble books. The breathing holes are protected by special covers that open at the right time. The respiratory system also includes trachea tubes, which supply oxygen to the internal organs.
Spiders, despite the fact that they are predators, have a well-developed central nervous system consisting of nerve cells. Nerve formations are located in the cephalothorax, and from them nerve endings are distributed, directed to all organs of the animal. These nodes, the number of which is 2, are the brain of the animal.
It is important to know! The number of nerve cells is very significant, since the volume of the brain accounts for up to 30% of the useful volume of the cephalothorax.
Features of reproduction
In spiders, reproduction is accomplished by mating. By the end of the mating period, the male loses his life. And the fertilized female begins to weave a cocoon for eggs, which she usually lays with the onset of autumn.
At first, the female wears the cocoon on herself, and then throws it off in a secluded place (a gap in the bark of trees or in non-residential buildings). With the arrival of spring, young (juvenile) spiders crawl out of the cocoon. They become sexually mature towards the end of summer. And the female, who took care of their birth, dies by that time.
Cross spider: male and female
How do spiders feed?
Spiders are obligate predators because they catch prey on their own, but they do not have teeth. As a rule, the victim herself falls into the web and the spider has to use its poison to eat the prey. The peculiarity of the poison is that it dissolves the flesh of the victim, making it a kind of broth. In addition, the poison serves to immobilize the victim. As a rule, all spiders are poisonous, but few pose a danger to humans.
Amazing spiders. Amazing spiders 2015 HDTVRip
What to do if you are bitten
The spider bite is not fatal to humans, cattle, horses, dogs, sheep, the danger exists only for rats, rabbits and mice.
Usually, the spider bites a person by accident if he falls into a web where a hunter is waiting for his prey. Its poison is a colorless, cloudy and viscous liquid.
Preventing a Bite
To avoid a spider bite, you should follow some simple recommendations:
- When going to bed in nature, be sure to close the entrance to the tent at night;
- Before going to bed, carefully examine your bed, clothes and shoes;
- be careful near the webs, remember that there is a cross nearby that is waiting for the victim;
- be careful during country and garden work;
- be vigilant when in abandoned old premises;
- If you find a cross, do not try to pick it up.
Symptoms
The cross spider is able to bite through only the thinnest skin. The pain of the bite is comparable to that of a bite; a person feels a prick with a thin needle, and sometimes does not notice anything at all.
A white spot with red or pink edges, small in size (no larger than a five-kopeck coin), appears at the site of the lesion.
The main signs of a spider bite that develop after 5-20 minutes include:
- irritation at the site of injury;
- aching joints;
- weakness;
- skin redness;
- slight chills;
- subcutaneous hemorrhages;
- slight increase in temperature;
- edema;
- hardening of the skin;
- headache;
- burning.
First actions after a bite
If you are bitten by a cross, the following actions should be taken:
- wash the affected area with running water and soap to eliminate the risk of infection;
- Apply ice or a cold compress to the bite site;
- if you have a fever or headache, it is recommended to take paracetamol;
- If you have an allergic reaction, take any antihistamine that does not require a prescription.
If there is a rapid increase in symptoms or a child has been bitten, it is recommended to seek help from a doctor.
Consequences
The cross releases epeirotoxin
, which is absorbed and completely eliminated from the human body within 24 hours. There may be slight swelling at the site of the bite for several days.
If there is no improvement in the person’s condition, the following actions should be taken:
- apply cold to the affected area;
- use anti-inflammatory ointments: Sinaflan, Kremgen;
- Lubricate the area with alcohol.
Do not scratch the site of a spider bite. This can lead to the development of a purulent process when infection enters the skin.
It makes no sense to burn or cut the skin when bitten; it does not have serious consequences. This is just additional trauma.
To date, not a single fatality has been reported from a cross bite. But in some cases, after recovery, soft tissue necrosis is observed at the affected area.
Exercise caution when out in nature. Remember that a cross spider will never attack a person on its own. Do not provoke a bite, and if affected, take measures to prevent complications from occurring.
Do not provoke a bite, and if affected, take measures to prevent complications.
You need to enable JavaScript to vote
What types of spiders are there?
These arthropods are found in any living conditions, so they are found literally everywhere: in the ground, on trees, on bushes, in caves, etc. The only thing is that they cannot fly, although some species easily move through space on their webs. At the same time, arthropods can cover enormous distances.
Conventionally, spiders are divided into several groups. For example:
- On those living in burrows.
- Living on the surface of the earth.
- Living under bushes.
- Tree dwellers.
Tree spiders can be easily identified by the shape of their web, which resembles a target. Spiders that live in burrows use webs to secure the soil so that it does not collapse. Spiders that live on the surface of the earth form webs horizontally, using pieces of soil for reliability. Those that live under bushes weave webs in the form of huts, and they camouflage it with the help of branches and earth. Arthropods use all forms of webs as a signaling system, which signals that living creatures have been caught in the trap.
Interesting to know! The silverback spider is the only species that can live in water.
Interesting classification
Everyone knows that there are lovers of large tarantula spiders who classify their favorites depending on their speed characteristics. For example:
- For Dummies" . These are slow-moving members of this species that many people like to film. They can sit quietly on the palm of a person and move extremely slowly.
- For the “advanced” . These arthropods move quite quickly, so it’s unlikely to be captured on video.
- For professionals . They move so quickly that it is unlikely to notice in which direction the arthropod disappeared.
If we take into account such speed characteristics, it is not difficult to imagine how many species humanity does not yet know about.
THE STRANGE AND UNUSUAL SPIDERS IN THE WORLD
Deadly poisonous spiders
As a rule, the majority of spider species are not dangerous to humans. The only problem is the presence of cobwebs in the most inappropriate places for humans. It should be noted that there are very poisonous species, the bites of which can be fatal to humans.
Deadly ones include:
- Black widow, as well as karakurt.
- Brazilian spiders.
- Brown recluse spider.
Black widows received such an interesting name due to the fact that after mating, if the male does not have time to leave, the female simply eats him. This dangerous species is distributed across almost all continents. They hunt their prey like a lasso using their web. The most famous in this regard is the American black widow, and as for the other representatives of this genus, they do not pose a serious danger.
North American black widow
On the North American continent, you can find up to 5 species of black widows, which are distinguished by their black body color with the presence of red spots on the abdomen.
It is important to know! Not all black widows are distinguished by their black body color.
The main distinguishing feature of this kind of spider is the presence of long legs, as evidenced by photographs of these dangerous animals. A spider bite is somewhat similar to a pin prick, but after 30 minutes muscle cramps appear that spread throughout the body. When serums had not yet been invented, up to 5% of victims died from their bites.
South American black widows
Representatives of this genus, living in South and Central America, have been studied very little. It is known that up to 8 species live in these places. This is due to the fact that spiders inhabit hard-to-reach places that are not so easy to reach.
Karakurt
These poisonous and dangerous arthropods live in Eurasia and Africa. There are up to 18 varieties of them, differing in varying degrees of danger. These are the same black widows, but they are called karakurt here. Black karakurt prefers to live in the southern regions of the continent, including Crimea and the Mediterranean. Due to the fact that global warming processes are observed on the planet, black karakurt was found in colder regions. As a rule, the ideal conditions for this arthropod to live are high temperatures above zero.
The image and name of the spiders do not correspond to reality, since these types of karakurts are distinguished by the presence of large red spots on the back. The coloring of spiders can vary due to the fact that Eurasian species often interbreed. As a result, black karakurt can have a pure black color.
Interesting fact! In nature, there is also a white karakurt. This type of karakurt is not so poisonous, but children and allergy sufferers can suffer from their bites. They live in the same conditions as black karakurts.
Oceania and Australia
The Australian black widow is considered one of the most poisonous representatives of arthropods.
Latrodectus geometricus
The black widow of this species is distributed on almost all continents. If you look from the back, the spider is brown in color, and the red spot is located on the lower part of the abdomen. This black widow's paws are yellow-brown, and black stripes can be seen on their bends. Of all the representatives of this genus, it is considered the least dangerous creature and poses a danger only to children and the elderly.
Brazilian wandering spider
Until recently, it was believed that black widows were the most dangerous species of spider, but by 2010, the most dangerous species became known - the Brazilian soldier spider. The genus of these most dangerous arthropods includes about 8 species. Their habitat is limited to the tropics of South and Central America. The most interesting thing is that spiders of this species build hunting webs and hunt in an active way.
Interesting fact! The last species of these arthropods was discovered only in 2001.
After being bitten by a soldier spider, paralysis and suffocation occur. As a result of poison entering the blood, in 85 cases out of 100, complete cardiac arrest occurs.
Recluse spider
This is one of the species that represents the North American continent. Body color can be either brown or dark yellow or gray. The size of the paws can range from 6 to 20 mm. The recluse spider has only 6 eyes, compared to the majority of species. This can be seen in the photo if you enlarge the image.
During the daytime it prefers to be in shelter, and goes out hunting in the dark. Despite the fact that he does not hunt with the help of a web, he still weaves a web, but uses it as a shelter. It can easily be found in a person’s home, so it can easily climb into bed. If you press him down, he will certainly bite.
Over time, a necrotic ulcer forms at the site of the bite, which can heal for several years. There are also fatal cases when a child or a person with weak immunity becomes a victim of a bite.
10 Most Dangerous Spiders in the World
Danger of the cross for humans
The bite of a spider with a cross is no more dangerous for a person than if he were stung by a bee. Feels like an instant sharp prick. A swelling appears at the site of the bite, a small white spot appears in the puncture area, the skin around it turns red and itches. The body is freed from toxins within 24 hours.
More severe symptoms are experienced by people who suffer from an allergic reaction to insect bites. They may experience:
- headache;
- weakness and aching joints;
- chills;
- temperature increase;
- swelling, including mucous membranes;
- burning, tingling of the bite site;
- thickening of the skin in the affected area.
Note! Most often, the spider bites a person when he picks it up or the arthropod accidentally gets under his clothing. There have been cases when a spider climbed into a tent through an open window.
First aid for a bite
To minimize the consequences of a spider bite with a cross on the back, do not neglect first aid. It should be remembered that along with the poison, an infection can get into the wound, which will cause no less harm, and maybe even more, than the toxin itself. What should you do first?
- Wash the bite area thoroughly with cold running water and soap.
- If the swelling is severe, apply a cold compress, or you can use ice for a short time.
- Take an antihistamine, for example, suprastin, loratadine, zodac.
- After some time, an ointment that relieves itching and swelling (fenistil, sinaflan) can be applied to the affected area.
If a child is bitten by a spider, do not wait for a reaction to the poison to appear; consult a doctor immediately.
Spiders are moderately poisonous
As a rule, bites from these arthropods do not cause serious concern, but the bites result in swelling of the limbs, as well as severe pain. These spiders include:
- banana spiders,
- Tarantulas.
- Spider saku.
- Spider wasp.
The result of a bite from these arthropods is minor irritation, but too much venom can cause swelling of the limb.
Banana spider
These species have several names, depending on their habitat conditions. These are spiders that form extensive webs and are called large arboreal orb-weaving spiders. Depending on their habitat, they are called:
- Banana spiders.
- Large tree spiders.
- Gold weavers.
They grow up to 4 cm in length and have a paw span of up to 12 cm. They are not dangerous to people. In the event of a bite, the area becomes blistered and red, and all this is accompanied by a strong burning sensation. As a rule, the negative consequences of the bite disappear within 24 hours.
Tarantulas
Tarantulas are also called wolf spiders because they are members of this family. Of particular interest are the South Russian species and the Apulian tarantula. They are distinguished primarily by their substantial size, while they do not form trapping webs. They hunt at night, attacking various invertebrates and other spiders. They live in earthen burrows, up to 0.6 meters deep and up to 1.5 cm in diameter. The animals are distinguished by the gray color of their body, while the abdomen is covered with hair. The paws of the animal are of medium size.
Tarantulas prefer to live in hot regions of the Eurasian continent, in dry steppes. They are especially poisonous in the spring, when they have a lot of unspent poison. At the same time, for a tarantula to bite, you need to really want it. To anger an animal, you will have to pull it out of the hole, and then take it with your bare hands. It should also be remembered that tarantulas are capable of making vertical jumps if they are in danger. But this does not mean that he will attack a person, since at the first danger he will try to hide.
Interesting fact! In some countries, large tarantula beetles are called tarantulas.
Spider sak
This animal has another name - yellow heyracantium. Until recently, it was a representative exclusively of the southern regions, but as a result of global warming, it can be found in the central zone of our country. Its wide distribution was also facilitated by the spider’s partiality to the smell of oil. In this regard, he is a frequent visitor to the car engine. It is located between the engine mechanisms, and the ventilation system is covered with cobwebs.
The spider is not impressive in size, since it is only 1.5 cm in length maximum. The paw span is about 2.5 cm. The body is yellow-brown. A characteristic difference is the massive chelicerae with long extensions in the form of needles. They help the spider hunt at night and are very active. In the photo you can see what this spider looks like.
In the event of a bite from such an animal, soft tissue necrosis develops. In addition, the bite may be accompanied by nausea, severe headache, and high fever. The bite site becomes red and inflamed.
Argiope or wasp spider
Represents the family of orb-weaving spiders. Due to the unique body coloring, reminiscent of the body coloring of a wasp, the spider was named just that - the wasp spider. Several species occur in nature. Their habitat is limited to 52 degrees north latitude.
Interesting to know! The wasp spider is a species that can fly a considerable distance on its web.
It hunts by weaving round trapping nets. He does this at dusk. The main diet consists of flying insects. The bite is very painful, but not dangerous. As a rule, the bite site becomes inflamed.
Symptoms of cross bites
For large animals and humans, the venom of the cross spider is not particularly dangerous, because it is too small to cause significant harm to a large organism.
Maxim, when it is possible to kill a mouse or a rat with this dose.
And yet, the bite of a spider of this species is not completely harmless. If you accidentally fall into the web of this arthropod creature, a person may still suffer from its bites. After all, the spider takes as a victim anyone who causes its “catching net” to vibrate. And for the purpose of self-defense, of course, the spider will bite anyone.
The cross can also bite when a person tries to pick it up.
The clinical picture of spider bites will be as follows:
- The bite site turns white and looks like a bee sting;
- The spot grows the size of a nickel and turns red at the edges;
- Swelling at the puncture site;
- A burning sensation at the site of the bite.
And if a person suffers from allergic reactions, then it may well be that the bite of this insect will cause the following symptoms:
- General weakness of the body;
- Skin rashes in the form of red spots;
- Headache;
- Painful syndrome in the limbs;
- Increase in body temperature;
- Hardening at the site of the bite.
As a rule, greater sensitivity to cross bites is observed in children and allergy sufferers.
Therefore, these groups of people may experience not only the symptoms described above, but also develop more serious complications in the form of suffocation, intense swelling, and even disruption of the cardiovascular system.
If such a clinical picture develops, it is very important to immediately call a qualified medical team for emergency care and hospitalize the victim for adequate therapy and constant medical supervision.
Safe spiders
This group of spiders includes those representatives that are either unable to bite through human skin, or their venom is too weak to harm. Spiders of this class include:
- Tarantula spiders.
- Cross spiders.
- Harvester spider.
- House spider.
- Jumping spiders.
Man is of no interest to spiders, since their purpose is completely different - to live in nature so that no one touches them.
Tarantula spiders
These animals represent a group of the largest spiders on the planet, among which the goliath spider is considered the champion. Its size is simply amazing - about 10 cm, and its paw span is about 28 cm. These spiders are also distinguished by the fact that their body is covered with thick fur of red-brown shades. This monster is not dangerous for humans, but its falling stubble can lead to various allergic reactions.
Cross spiders
They are considered relatively large representatives of their genus. They can be easily distinguished from other types of spiders by their characteristic pattern in the form of a cross located on the back of the animal. This is a typical representative of gardens, parks, forests and other green spaces. It uses a web as a tool to catch food. The spider itself may be in a shelter of old leaves.
Spider bites are not dangerous even for children, but they can let the child know not to touch it.
Harvester spider
This living creature on long legs constantly annoys humans by constantly weaving a web, which has to be constantly removed. It prefers to live in houses or apartments, but it can also be found in other outbuildings. Not dangerous for humans.
Interesting to know! Haymakers weave webs chaotically in all hard-to-reach places with great diligence, after which they have to regularly remove the fruits of their diligence.
House spider
Represents the family of funnel-web spiders. The family got its name due to the weaving of funnel-shaped webs. It can often be found in a person’s home, as well as in other places. The female grows in length up to 7 - 12 mm, and the male is more modest in size - only 6 to 9 mm. The body of the animal is distinguished by a brown tint. It does not show aggression towards people, but if you disturb it and put your finger in a shelter, it will definitely bite. In this case, there will be no negative consequences from the bite.
Jumping spiders
They represent one of the most numerous families. Found almost everywhere except Greenland. They differ in that they can jump, but they go out hunting mainly during the day. Horses are also distinguished by the unique structure of their bodies, namely the presence of a unique hydraulic system. Thanks to such capabilities, which make it possible to regulate pressure in the circulatory system, spiders can make jumps that are incommensurate with their own parameters.
Interesting fact! In the racehorse family there is one species that is considered a vegetarian. This species inhabits Central America and feeds on trees of a certain type. Despite this, in conditions of lack of moisture they can eat their relatives.
Peacock spider
A unique species of spider, representing the genus of horses. This small living creature is endemic to Australia and is therefore not found anywhere else on the planet. This unusual creature got its name due to the fact that it practically copies the behavior of the most beautiful bird. Moreover, the male also has brighter colors compared to the female. During mating periods, the male spreads his tail and also uses the lateral scutes located on the abdomen. Together with his hind legs, he lifts them up. If there is no female, then the males wrap their scutes around themselves.
Hobo spider
They do not weave hunting webs, but hunt various insects from ambush. By the nature of their hunting and the structure of their eyes, they can be compared with wolf spiders. The female still weaves a web, but for completely different purposes - when she forms a cocoon, she lays eggs in it. At the same time, she carries the cocoon on her back.
Hunter bordered
It represents the family of hunting spiders and can grow up to 2 cm in length. It is distinguished by a yellow-brown body color, although depending on the living conditions, the color may have darker tones. A characteristic feature is the presence of a white stripe on both sides of its body. It prefers to settle on the banks of various bodies of water located in the temperate zone of Eurasia. The species is quite unique because individuals can move through the water and even dive if necessary. It has another name - the fishing spider, as it can hunt for fish fry.
Spider green
In fact, such a species does not exist in nature. Various spiders belonging to one genus or another can have a similar coloration. For example, green color can be:
- Jumping spiders.
- Huntsman spiders.
- Lynx spiders.
To find out how dangerous a green spider is, you first have to decide on its type.
Crab spider
This type of spider also does not exist, but some of the species can move sideways, like crabs. For example:
- Neocribellatae species.
- Thomisidae species.
- Philodromidae species.
It is important to know! These three types of spiders are not considered dangerous to humans.
Appearance
The abdomen itself is rounded with no segments. If you look at its lower part, you can see 3 pairs of arachnoid warts, which contain about a thousand glands. It is the glands that are responsible
for the production of webs for a variety of purposes: to build a trap, weave a cocoon, or to create a shelter.
Female size
exceeds the size of the male. For example, the body length of a female is 17–40 mm, and that of a male.
10–11 mm. This type of cross has a body cavity of a mixed type or, in other words, a mixocoel. This cavity was formed as a result of the merger of the primary and secondary cavities. The body of the crusader is covered with a yellow-brown chitinous shell. During molting, the cross
sheds the shell, thereby renewing the chitinous layer.
The cross has 10 limbs:
The cross spider has very poor eyesight, despite the fact that it has 4 pairs of eyes. This spider distinguishes only light, shadow and blurred silhouettes. But this does not prevent him from having excellent orientation in space, because he has a well-developed sense of touch. It is carried out thanks to tactile hairs covering the body. Every type of hair
has its own function: some perceive sound, others detect changes in air movement, and still others react to various kinds of stimuli.
The lifespan of a spider is from 1 to 2 years and depends on the type of crusader.
Respiratory organs and heart
The crusader breathes using his abdomen, because the organs responsible for this important function are located there. Respiratory organs are presented
in the form of a pair of pulmonary sacs with numerous leaf folds. They contain air and hemolymph circulates, while being enriched with oxygen. This name refers to the fluid that flows in the vessels instead of blood. The respiratory organs of the cross also include trachea-tubes, collected in two bundles. They open through a hole located at the bottom of the abdomen.
The heart, in the form of a long tube, is located in the dorsal part of the abdomen. Large vessels will withdraw from the heart
.
Excretory system and digestion
The excretory system is presented as:
- Coxal glands. A system of canals departs from them, which ends in the form of excretory ducts in the area of the base of the walking legs.
- Malpighian tubes. With their help, metabolic products leave the crusader's body.
Digestion in the cross spider is external. In other words, the crusader’s body is not able to digest food, so it builds traps from cobwebs.
Features of the web
The crossers are updating their web
almost every day, due to the unsuitability of the old one. The reasons why a spider needs to change its web are:
- Gaps due to prey being trapped.
- Holes caused by large insects that are unsuitable for spider feeding.
The web is being weaved
at night. This is explained by the fact that at night the crossbird feels completely safe, because birds that feed on insects have been sleeping for a long time. The new prey trap will be ready for use in the morning.
The spider has a scheme for weaving a web, laid down at the genetic level. The web always has a certain number of circles and spirals, and the spaces between the weaves are the same. Young males build webs no worse than adults until they reach sexual maturity.
Reproduction
Spiders begin to mate in the autumn season. A male who has reached sexual maturity
, goes in search of a female who is waiting for him in her weaving. As soon as the spider has found its chosen one, it attaches a thread to its web, as if inviting it to itself. For the female, this means that it is time to reproduce and she leaves her network. The male representative dies after mating.
In turn, the fertilized female builds a cocoon where she will subsequently lay her eggs. For several days the cocoon is under the protection of the mother. The female then finds a secluded place in the cracks of the walls, in which the cocoon survives the winter. The female dies, and spiders emerge from the cocoon in the spring. In summer, the new offspring are ready to reproduce.
Other arachnids
Central Asia and Africa are home to large arthropods, which are unknowingly confused with spiders. In fact, these are salpugs or, as they are also called, camel spiders. Unlike spiders, these living creatures do not have poisonous glands or glands for creating webs, but they are armed with teeth.
Spiders cause a feeling of fear in many people, but this is more likely due to ignorance. In fact, these are quite harmless living creatures.
10 Most Amazing Spiders in the World
