There are several species of crab spiders on the planet: some live in the sea, others live on land. The similarity of forms is all that unites them. The name of the same name - crab spider - given to completely different animals, introduces some confusion. Among them there are bright representative crustaceans with huge size. There are also miniature individuals related to arachnids.
History of the study of the giant Japanese crab spider
The giant spider crab is recognized as the largest crustacean in the world. Its first description was made by Japanese naturalists in the 17th century. Western scientists became acquainted with it only in 1727, after the publication of the German biologist E. Kampfer. A little later this huge sea life will give a name Macrocheira kaempferi, consonant with the name of the German naturalist who told the world about its existence.
Biological description
The Japanese spider crab is incredibly huge. The span of the stretched limbs of individuals, reminiscent of spiders in structure, approaches 4 meters. And this is with a relatively small body. The cephalothorax of the “monsters” reaches 37-60 centimeters in diameter. The weight of adult specimens approaches 20 kilograms. Females are slightly inferior in weight to males. Crabs have the most powerful weapon- claws growing up to 40 centimeters in length.
Area
Pacific waters washing japanese islands Honshu and Kyushu are the home of these fantastic arthropods. Sometimes they enter the Russian Far Eastern possessions. Adult crab spiders have colonized the upper territories of the continental slope. Here they go 300-400 meters deep. They feed on shellfish and fish.
Reproduction
The crab spider reaches sexual maturity at 10 years of age. With the onset of spring, adults begin migration, moving to coastal waters. There they give birth to their numerous offspring. Each female will hatch over 1.5 million larvae. Only one of them will survive small part. The lifespan of these crustaceans is 50 years. Although there are some specimens that live up to 100 years.
Usage
The meat quality of adult crab spiders is low. On great depths Their main food item is dead animals. Because of this, the meat tastes bitter. Adult “monsters” are caught in isolated cases. They are placed in aquariums and shown to visitors to aquariums.
Young animals are another matter. The meat of young crab spiders is tender. It is considered a delicacy. Catching young animals is not difficult at all. The abode of crabs is coastal waters. Here, hunters set traps with bait, where they easily catch individuals who have not gained sufficient life experience.
Thus, a significant number of young animals are exterminated without reaching maturity and without producing offspring. This raises serious concerns among experts. They are sure that giant crab spider there is danger. If measures are not taken to protect it, the population will quickly decline to a critical level, or even disappear completely.
Characteristics of the flower crab spider
This animal has nothing to do with crustaceans. This is a representative of arachnids from the sidewalker family, which includes about 2000 species. These species are so named because of their characteristic manner of movement.
These spiders do not spin webs. Their weapons are their front paws and their ability to camouflage. Almost all the time yellow spider- the crab spends time on flowers, watching for prey. They do not threaten a person in any way.
Appearance
Males and females differ in color and size. Females are small - only 10 mm in length. And the males are tiny compared to them. Their body length is only 4 mm.
The white or yellowish abdomen of males is decorated with long dark stripes. Their cephalothorax is black. The forelimbs are colored with brown and black stripes. The hind legs have the same color as the abdomen. Females “show off” in bright outfits of green and yellow shades. Their sides are often painted with red stripes.
Spreading
A yellow crab-like spider has taken over a vast territory stretching from the subtropics to Arctic zone. It is found in Alaska, the USA, Japan and Portugal. All of Europe became his abode, with the exception of Iceland. He lives on open areas, tightened big amount flowering plants.
Nutrition
The flower crab spider guards its victims on flowers. Depending on the color of the inflorescences, it also changes its own pigmentation. Only adult individuals are capable of such camouflage. Their eyes help them control body color.
These arthropods are real hunters. They feed on a wide variety of pollinators: butterflies, bees, wasps, hoverflies and small bugs. Often the prey is much larger than the most insidious predator.
Having waited for the victim to lower its head into the stamens, the yellow spider attacks it, spreading its front legs wide. It bites the caught prey on the neck. Poisonous bites instantly kills the victim.
Thanks to its ability to skillfully camouflage itself, the crab spider remains unnoticed while in close proximity to its prey. It prefers to hunt on plants with yellow or white inflorescences, which is why its body has the same shade. Ranunculaceae and cornflower are his favorite flowers for hunting.
However, according to scientists, the yellow color of spiders is just special case. In fact, the color can be any, the main thing is that it matches the color of the plants.
Features of reproduction
The mating season for yellow spiders begins in the summer. Males find a suitable female and mate with her. Having completed mating, the male leaves. The females are engaged in hanging cocoons with eggs, securing them on the sides of the inflorescences. The young overwinter underground.
The arachnid family has very beautiful and unusual creatures in its ranks. They look like both spiders and crabs at the same time. Their name is also very interesting - side-walking spiders. Sometimes the creatures of nature are simply incredible, like, for example, these spiders that can hop, jump and move sideways. Because of this unique method of movement, they got their name - sidewalkers. They are also called jumping spiders and crab spiders. They look cute and cute. Even those people who are terrified of spiders do not shudder at the sight of them. An interesting fact is that these beauties need a web only to move from the upper tiers of plants to the lower ones. They also need spider threads for mating games. With the help of threads, these small animals (and spiders are just animals, and insects, as many people think) attract a partner.
Side-walking spider: description, reproduction
The physique of these animals is unusual. The front pairs of legs are longer than the others, and they are also turned upside down. It is because of this structure of spider legs that these wonderful creatures move sideways. The body appears flattened and angular. This structure makes the animals very similar to representatives of the crustacean family, which is why the second name for these creatures is crab spiders. They can also move backwards just like their clawed counterparts.
The color of sidewalk spiders depends on the environment in which they live. If on the ground, the spiders will be dark brown or gray. If on flowers, then the animals can be of different bright colors. It is very difficult, almost impossible, to notice spiders. Nature gave them a color that makes them blend into their surroundings.
The mating season for sidewalk spiders begins in early June. The male looks for a female, attracts her attention to him and begins to court her. If the female reciprocates, the sidewalk spider climbs onto her back and moves to her genital opening. Then he alternately introduces the pedipalps, which contain seminal fluid. After the first mating, the spiders take a short break, rest, and then mate again. The female hides the finished cocoons from predators by attaching them to the leaves or stems of plants.
Different types of spiders
The spider crab, or sidewalker, is general definition many species of spiders, but most of these animals belong to the family Thomisidae. In total, there are about two thousand species of side-walking spiders, which are divided into 170 genera.
The most famous are flower crab spiders. They hunt in flowers and are painted in bright colors. For example, in Uruguay, these animals imitate tropical flowers - the spiders are very beautiful and seem completely harmless in appearance.
Excellent hunters
The sidewalk spider is very patient. Most During this time, these handsome guys sit completely motionless, waiting for prey. Sidewalkers do not need a web for hunting; they do not use it to catch prey.
The weapons of spiders of this species are the front legs. Having identified a target, the predator rushes at the prey using its strong forelimbs, bites and injects poison. Their ability to merge with a plant, tree or earth greatly helps these creatures hunt. They perfectly adapt their “clothes” to their surroundings. The crab spider has an excellent appetite; it can feast on 4 large bees in one hour. Prey that is much larger than the hunter himself is quite suitable for breakfast for a small predator.
Sidewalkers are a danger to humans
There are very few lovers of this type of insect such as spiders. In most cases, a person experiences unpleasant emotions when they see them. The side-walking spider is not disgusting in appearance, but on the contrary, cute. Only with a beautiful shell, these creatures still remain predators and can pose a threat to health. There are few cases of attacks on humans, but they still exist.
The venom of these animals contains toxins that can poison the body. If bitten by a crab spider, a person may experience headache, weakness throughout the body. In this case, you must immediately consult a doctor. The consequences of a cute spider bite can be serious.
Everyone is used to seeing spiders in their home. Yes, and on the street in the warm season they are found, especially outside the city. But have you ever thought that these lonely spiders are part of a huge family, which has approximately 42 thousand representatives?
The stereotype that spiders spin webs is a misconception. Not everyone knows how to spin it. For example, side-walking spiders, whose size does not exceed one centimeter, are not endowed with the art of spinning.
Where do sidewalk spiders live?
You can meet such a spider in any corner of the globe. But warm countries they love more. Creatures are able to adapt to different climatic conditions, and one of the ways is coloring. Each type of side walker has its “own” shade.
It is known that in the spider family of side walkers there are 170 genera and approximately two thousand species. Scientists were able to study well only three types of these spiders: the white or yellowish flower spider, the yellow crab spider and the blue ornate spider.
What do sidewalk spiders look like?
The body of spiders is flattened and angular. Sidewalkers have long, upward-curved forelimbs. Behind unusual look they are often called crab spiders. Spiders have “borrowed” a method of movement from crustaceans and, if the need arises, they move sideways or back away.
How sidewalkers hunt
Creatures that cannot spin webs are excellent hunters. To catch food, which is often many times larger in size, they set up ambushes, hiding in flowers, leaves, or on a tree. The spider grabs its victims with its front legs.
Sidewalkers change color so as not to stand out against the general background. Those who choose plants for hunting have a bright range of colors, and those hiding in the grass or tree bark are usually brown or gray.
Side-walking spiders are not dangerous to people, despite the toxic poison, because they attack extremely rarely.
Cute spider? Repost and tell your friends about it.
Spiders are quite common in our house. But we never think that this is just one species of a huge order, numbering about 42,000 species.
Each of us knows that spiders weave webs. But it turns out that not all varieties have the art of spinning.
Such individuals belong to the side-walking spiders. They reach a size of only 1 cm.
Description of the spider
Body structure
The body of side-walking spiders has two parts connected by a small tube:
The cephalothorax (prosoma) has the following features:
- divided into head and chest sections;
- on the head there are two pairs of limbs. Chelicerae are equipped with poisonous glands and a claw for their secretion. The pedipalps are formed from six segments; in males they are equipped with a mating apparatus;
- on the frontal part there are 8 eyes, 2 of which are main, the rest are additional;
- 4 pairs of limbs are attached to the cephalothorax behind the pedipalps. Side-walking spiders are able to move sideways due to the upward-turned front surfaces of the first two pairs of legs. With its movements it resembles a crab;
- The spider's leg consists of several sections: coxa, trochanter, femur, tibia calyx, pretarsus, tarsi with claw.
Abdomen (opisthosoma):
- oval shape;
- contains basic internal organs spider;
- The genital opening is located below.
Nutrition
Side-walking spiders are predators they are not afraid to attack even insects larger than themselves. Spiders wait for their prey for a long time, camouflaging themselves with the terrain (flowers, soil, bark). Side-walking spiders are very mobile and when the long-awaited profit appears, they quickly grab it with their feet and inject their paralyzing venom into the body of the victim. Then, after some time, all the nutrients are sucked out of it, leaving only one shell.
Reproduction
Mating of sidewalk spiders occurs at the beginning of summer and consists of the following stages: 
- Searching for a female by a male, attracting attention to himself. If the female has accepted the gentleman's advances, he climbs onto her back.
- The male moves to the female's genital opening and alternately inserts pedipalps containing seminal fluid into it.
- After a short break, the act of mating is repeated.
- The female attaches cocoons to the stems or leaves of plants, hiding them from predators.
Varieties
Sidewalk spiders are terrestrial animals. Found everywhere on globe. In warm climates species diversity represented much more widely than in temperate and cold.
Spiders adapt to climate conditions different ways. One of them is coloring. All varieties of bocod spiders have their own shade. This family has 170 genera, in which about 2000 species are distinguished. The most studied are the following types:
Flower spider (Misutnena vatia)
- color white, yellowish;
- body size up to 11 mm;
- lives on flowers of the ranunculaceae and cornflower family;
- food: butterflies, bumblebees, bees;
- Habitat: Europe, North America.
Yellow crab spider (Xisticus luctuosus)
- the body of the male is dark brown, 4-5 mm long, the female is yellow – 7-8 mm;
- lives in meadows and forest clearings;
- distributed in the European part of Russia and the former USSR.
Ornamented blueberry (Synaema ornatum)
contrasting color: the bottom of the abdomen is black, the top is red or yellow with a black angular spot;
- body length of a male is 5-6 mm, female – 7-8 mm;
- lives on flowers of the Rosaceae family;
- feeds on insects;
- lives in the steppe and forest-steppe of our country.
Benefits for humans
Small spiders can be of great benefit to humans. Spiders are very voracious.
In one day, sidewalk spiders are capable of eating food weighing more than their body weight.The bulk of the food is flies, which are a breeding ground for many harmful bacteria.
The venom of side-walking spiders is planned to be used as pesticides in the future.
Frequent prey of the side-walking spider are agricultural pests: meadow moths, dipterous apple honeysuckers, aphids, bedbugs, and weevils.
In medicine, research is being conducted on spider venom for the treatment of arrhythmia, Alzheimer's disease, erectile dysfunction, and stroke.
What to do if you are bitten
Sidewalk spiders are not dangerous to humans, but their bite is still unpleasant due to the following symptoms: 
- redness, swelling, itching and burning of the bite site;
- headache;
- dizziness;
- weakness.
If you are bitten by a sidewalk spider, it is enough to apply ice to the wound and take antihistamines. The bite site can be treated with “Star” balm or Fenistil-gel.
We often mistake spiders for common insects, But it's not right. They have poisonous glands containing toxins at their disposal. All types of sidewalk spiders must be handled carefully to avoid the unpleasant sensations that bites from these little ones cause.
The side-walking spider or crab spider is one of the most interesting varieties order of arthropods.
Spider crab
Unlike his other brothers, he does not lure his prey into a web, but hunts by merging with environment, and taking a motionless pose.
It immobilizes the victim by injecting poison into it. Eating pests, the crab spider is a welcome guest on farmland. Scientists are of great interest appearance sidewalk spider and life cycle small predator.
The side-walking spider (lat. Thomisidae) acquired its unusual name due to its equally unusual appearance.
It has four pairs of limbs. Moreover, the two front pairs are turned with their surfaces up.
Appearance of a sidewalk spider
This feature allows him to move only sideways. But with the help of his front legs, he famously captures the victim, not giving it a chance to free himself.
This spider looks like a crab, and not only because of its lateral movement. When hunting prey, he is able to move backwards.
Only, unlike its marine counterpart, the crab sidewalk spider is very small. The body of spiders is flattened and angular. Its length in females does not exceed 1.2 cm, and males are half that size.
This species of arthropod has a body color that blends with the substrate. Spiders that live on flowers are quite brightly colored.
White spider crab
If the habitat is the bark of trees or the ground, the body of the animal is painted in gray or brown shades with a spotted pattern.
Nutritional Features
The crab sidewalk spider is a predator. But it does not threaten humans. He only likes insects, the size of which can be several times larger than the devourer himself.
These seemingly cute creatures wait for their prey for a long time, hiding in leaves, flowers, grass, and tree bark, changing color and merging with them.
While waiting for prey, the sidewalk spider pretends to be dead. When the insect crawls towards it in the hope of getting an easy prey, the crab spider grabs it with its front legs and injects nerve poison into the body.
Sidewalk spider holding its prey
When the prey stops moving, the animal sucks out all the nutrients from it, leaving only a chitinous covering.
Features of reproduction
Sidewalk spiders are heterosexual. Males have pedipalps on the head of the body, equipped with a mating apparatus.
They begin mating in early summer. Males try their best to attract the female's attention and then climb onto her back.
Since males are much smaller, they slowly move towards the female's genital opening, located in the back of the body.
Then the males alternately insert pedipalps containing seminal fluid into it. After mating, the couple rests and consolidates the result by repeated mating.
The female lays eggs, wraps them in a cocoon of cobwebs and attaches them to the lower parts of the leaves, protecting them from other predators.
At one time, the female lays several hundred eggs. When the cubs are born, the adult spiders provide them with food and protect them from enemies. The lifespan of these animals does not exceed one year.
Where does the animal live?
There are about 2 thousand species of side-walking spiders.
The most common are:
- white sidewalk spider;
- yellow sidewalk spider;
- flower side-walking spider.
This creature is found everywhere. The crab spider adapts to the harshest climatic conditions.
Flower sidewalk spider
But, like any other animal that does not have thick fur, it prefers places with warm and temperate climate. It cannot be found in the Tundra and Antarctica.
But even in the desert it is cute creature It's unlikely to be found. The crab spider lives in areas with rich vegetation. The yellow crab spider prefers to live in meadows and forest clearings.
Yellow sidewalk spider
The favorite foods of the flower crab spider are butterflies, bees and bumblebees. That's why he is a frequent visitor to garden plots, hiding from prying eyes in flowers.
The side-walking spider is deadly to humans - truth or myth?
These representatives of the arthropod family secrete a very toxic poison that almost instantly immobilizes the victim.
Sidewalk spider on the hunt
And here a completely logical question arises: “Is the side-walking spider dangerous or not for humans?”
The arthropod is not dangerous to humans for several reasons:
- it does not attack people:
- the concentration of poison in such a minuscule creature is even more minuscule;
- this amount of poison is not even enough to paralyze a pet.
Only small representatives of the animal world (hamsters, mice, rats, etc.) can feel its influence.
Conclusion
By looking at the photo of the side-walking spider, you can appreciate the diversity of these representatives of the fauna.
The coloring of the body, merging with the environment, leaves them invisible not only to potential victims, but also to the human eye.
And since the food for the predator is mainly pests of garden crops, crab spiders bring undeniable benefits to humanity.
Video: Side-walking spider from the family Thomisidae
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