Class Arachnids today has more than 35 thousand different species.Dwell in the environment they are virtually everywhere.Among them are completely harmless to humans representatives of arachnids.But there are poisonous, and even those which are parasitic on the body parallel to the transferring various infectious diseases.
General characteristics of the class of arachnids
Features spider structure related to their adaptation to life on land.Class representatives are land arthropods having eight pairs of limbs.
representatives arachnids have the body, consisting of two divisions.In this connection it may be represented by either a thin wall or dense staple.Antennae of representatives of this class are not available.
In front of the trunk limbs are arranged such as mouthparts and walking legs.Arachnids breathe using lungs and trachea.The bodies of the simple.Some species are completely absent.
nervous system represented by nerve nodes.Skin tough, three-layer.There brain, consisting of front and
first insects have mastered to life on land, it became the representatives of arachnids.They can conduct both day and night active existence.
class spider is quite extensive, so if we talk about the environment, its representatives meet on the territory of Russia.Some feed on insects that prey caught in their nets woven, other just attack."Hunters" in this class are mostly feed on insects, but some bites cause to people and animals, causing various diseases.Some members prefer to live in the human or animal body, while others are parasitic only on crop plants.
scientists-zoologists conventionally divided the class into several groups of arachnids.The main squad are spiders, scorpions, mites, solpugi.
Scorpio - is not a typical spider, that is why it is in a separate party.
Arachnids representatives of the "Scorpion" are small, no more than 20 centimeters.His body is composed of three well-defined sections.On the front are two large eyes and five pairs of small side.It ends the body of a scorpion's tail, which is toxic iron.
body is covered with a thick and hard cover.Scorpion breathing with the help of light.Their environment, they have chosen the area with warm and hot climate.This scorpions are divided into two subspecies: living in humid areas and in dry places.Drinking air temperature is also ambiguous: there are subspecies, preferring a warm climate and high temperatures, but some great tolerate cold.
Livelihood mined scorpions in the dark, increased activity in the different hot time of the year.Scorpion finds its prey, catching the oscillatory motion of a potential victim.
If we talk about what kind of spider is viviparous, the scorpion is in its most brooding.However, there are egg-laying.The growth of nuclei located in the female body - the process quite soon, and pregnancy can last more than a year.
Kids are born in the shell, and immediately after the birth mother cling to the body by means of special suction cups.After about 10 days brood separated from the mother and begins to exist separately.The period of maturation in young animals lasts about one and a half years.
poisonous scorpion tail is a body attack and defense.However, the tail does not always save his master from predators.Some animals are able to avoid the blows, then he becomes a predator eating.But if the scorpion stung all the same sacrifice, many small invertebrates almost immediately killed by injection.Larger animals can live for a day or two.
for human aggression scorpion fatalities does not end, but in modern medicine were cases with very severe consequences.On the site of the lesion there is swelling, which can be quite painful, and the person becomes more sluggish and may experience bouts of tachycardia.After a couple of days, everything goes, but in some cases symptoms is maintained over a longer period.
Children are more sensitive to the effects of scorpion venom.Among children reported and cases of death.In any event, after an insect bite should immediately seek for skilled care in a medical institution.
Recall that we consider the class of Arachnids.Representatives of this group are common in countries with warm climates.For example, very often they can be found in the Crimea.
differ from scorpions great dismemberment of the body.At the same time, hard jaw solpugi perform the function of catching and killing prey.
solpug have no poison glands.Attacking man solpugi damage the skin with sharp jaws.Quite often it occurs simultaneously with bite wounds and infection.The consequences are: inflammation of the skin at the site of damage, accompanied by pain.
It was characteristic of arachnids, solpugi squad, and now look at the next party.
This is the most numerous group, with more than 20 thousand species.
representatives of different species differ from each other only web form.Ordinary houses spiders, which can be found in almost every home, weave the web, shaped like a funnel.Poisonous representatives of the class create a spider web in the form of a rare hut.
Some spiders do not weave the web of all, and lie in wait for their prey sitting on flowers.Coloring insects in this case adapted to the group of plants.
also in nature there are spiders that hunt their prey, just jumping on it.There is another, very special category of spiders.They never stay in one place and constantly on the move in search of prey.Call them wolf spiders.But there are also hunters ambush, in particular, the tarantula.
structure of spider
The body consists of two sections connected by a partition.In front of the torso located eyes, beneath them, hard jaw, inside of which is a special channel.It is for him the poison glands of the body enters the captured insects.
bodies of sensitivity are the tentacles.The body covers netyazhёly spider, but a solid cover, which grows reset spider, then to be replaced by another.
on the abdomen are small growths, cancer, producing a web.Initially, the threads are liquid, but quickly becomes solid.
digestive system spider is quite unusual.After catching prey, he injects into it the poison that kills first.Then, in the body of the victim enters the gastric juice, dissolve completely the interior of captured insects.Later, a spider sucking the resulting liquid, leaving only a shell.
Breathing carried out by means of the lungs and trachea at the front and rear of the abdomen.
circulatory system, like all members of the spider consists of the heart tube, and of the open circulation.The nervous system is represented by a spider nerve nodes.
spiders multiply method of internal fertilization.Females lay eggs.Later one of them and there are small spiders.
The squad includes Ticks are small and microscopic arachnids with undifferentiated body.All ticks are twelve limbs.They feed on these representatives of arachnids both solid and liquid food.It depends on the species.
digestive system ticks branched.There are also organs of the excretory system.The nervous system consists of nerve cord and brain.
mites multiply by laying eggs.Representatives of class heterosexual.Their life reaches six months, max.But there are also real centenarians.
ticks inhabit, like spiders everywhere: in homes, gardens and fields.Some representatives are able to cause significant harm, damaging plants and grain.Quite often the ticks are carriers of serious diseases.
Characteristics of some of the class Arachnids Spiders
some species during the hunt are not using the network.Among them is the crab spider.Hunter waiting for prey, hiding in the flower petals.Greenish-yellow color of the shell is almost exactly the same as the color of sepals, helping to camouflage the spider.He was not able to notice even the bees.Spider attacks the victim at the time when the insect hangs his head in the stamens.
Here is another characteristic of arachnids (order Ticks).Consider the taiga tick.Habitat, he chose the Far East, but also occurs in the European part of the country.
dimensions of the male of about 2 mm, while the females are larger than almost doubled.The larvae actively feed on small animals, but the growth is happening and change "master".The mite has moved hares or chipmunks.Sufficiently developed and strong individuals chosen victim cattle.
Mouth apparatus, like all members of the class, is located in front of the trunk and presented proboscis and strong sharp teeth.With their help, the tick is held on the body of the victim to saturation.
It was a brief description of some members of the class of arachnids.
We hope that the information will be useful to you.