Digestive system spider krestovik. What are the features of the structure and behavior of the spider krestovik. Features spider-krestovik

Research topic:   “How does the spider cross get food?”

Purpose of the study:   Find out how the hornbug spider learns about its prey in a web of prey.

Research hypotheses:

Suppose that the spider tusk can wait for prey.

Suppose a cross spider feels hesitation when its prey enters the web.

Objectives of the study:

To form an idea about the peculiarities of life and development of the cross-spider;

Develop classmates interest in the world;

Research methods:

Observation;

Reading popular science literature;

Search for the necessary material in the computer network Internet.

Academic disciplines close to the subject of the project:   the world.

I Introduction

1. Justification of the choice of the topic of work;

2. Goals and objectives of the work.

II main part

1. Features of life and development of the spider - krestovik:

a) Description;

b) Power;

c) Web;

d) reproduction;

III Conclusion.

http://pandia.ru/text/78/286/images/image002_75.jpg "align =" left "width =" 227 "height =" 302 "\u003e Description

The cross spider is one of the largest representatives of arachnids. These spiders are spread all over the world. On the upper side of the abdomen there are white or light brown spots that form cross. Thanks to this feature, they call him a cross.

The color of the spider spider is often adapted to its environment. Animals that set nets in darker places, such as in the woods or in shady bushes, are usually dark in color. Animals that weave their nets in sunny places and are exposed to intense sun exposure have a lighter shade. The size of the female is 20-25 mm, the male is 10-11 mm.

Nutrition

http://pandia.ru/text/78/286/images/image004_37.jpg "align =" left "width =" 272 "height =" 272 src = "\u003e When a fly, mosquito, small butterfly or other flying insect hits and the signal thread oscillates. At this sign, the spider rushes from its refuge to the prey and densely entangles it with cobwebs. It thrusts the claws of the upper jaws into it and injects poison into the body of the prey. takes refuge in a shelter.The content of poisonous glands not only kills the prey, but also acts on it as digestive juice. hour spider returns and sucks already partially digested liquid contents extraction, from which there is only chitin cover. Thus, spiders preliminary digestion occurs outside the body.

Spiders can also keep their prey in reserve.

If something not very edible falls into the net (for example, a poisonous wasp), the spider can help it to free itself by breaking the web.

Solid food, the spider can not eat.

Web

Weaves a vertical wheel-shaped trapping network into which insects that serve him as food fall.

The very method of building a web is very interesting. At the end of the abdomen of the spider are spider warts. The substance leaving through them, freezing in the air, turns into threads of extraordinary strength. The web's tensile strength is up to 260 kilograms per square millimeter (more than 6 times denser than natural silk, and 4 times more than nylon). The work begins with the fact that the spider attaches the thread to the highest point the place he chooses where the network should spread, for example, between two trees or branches. Having fixed the thread well, he begins to sway until he grabs the side branch. Thus, it turns out the crossbar. The greatest difficulty for the spider is to tightly pull the upper transverse thread, since in doing so it needs to move from one tree to another. If the thread is not tight enough, then it strengthens it with still short transverse threads .. jpg "align =" left "width =" 261 "height =" 195 src = "\u003e Spiders are semi-bony animals. Females are usually much larger than males. After mating, the male dies, and the female weaves a cocoon for eggs from the web. Eggs are laid in the autumn. The eggs are enclosed in a dense cocoon, which the female hangs in a secluded place: behind loose bark, in crevices, etc. After laying eggs in a cocoon, she carries it for some time hiding in a safe place. After a while, spiders appear. Like All spiders come out in spring.

Types of spider spiders:

  Common Cross ( Araneus diadematus) Foursquare (meadow) Araneus quadratus) The marble tress Araneus marmoreus)

When approaching the web of a person or anything else especially threatening, the female of the spider-spider grabs the prey with mandibles, and, covering its own body, exposes the upper part of the abdomen decorated with an awesome pattern to intimidate the opponent.

I have often seen a spider cracking down on prey. Thus, the hypothesis put forward: "Suppose the spider spider feels oscillations when the prey enters the network" was confirmed. The cross spider is a great worker as it weaves the most beautiful and regular web.

A typical representative of the class is the spider tussovka. The female is larger than the male; it has a large, rounded abdomen with a characteristic pattern in the form of a light cross on a dark background.

The body consists of two sections - the cephalothorax and the abdomen. Antennae absent; eight simple eyes on the front part of the cephalothora.

There are jaws (chelicera), a pedicle (pedipalps) and four pairs of walking legs on the cephalothorax.

At the base of the helicopter are poisonous glands, the ducts of which open on the tips of the claws. The chelating spiders pierce the integuments of the victims and inject poison into the wound.

There are no extremities on the abdomen; there are three pairs of spider warts.

There are about 1000 spider glands in the abdomen, which produce various types of spider web - dry, wet, sticky, etc. Different types of spider web perform different functions, one for catching prey, the other for building a dwelling, and the third is used to form a cocoon. On the cobweb young spiders settle.

The digestive system is represented by the anterior, middle and posterior intestine. The spider pierces the victim with chelicerae, injects saliva with enzymes, and then sucks in liquid food. Out-of-cavity digestion (= extraorganismatic) There is a liver.

Respiratory system. Pulmonary bags and / or trachea. In some small arachnids, breathing is carried out through the thin integuments of the body. Pulmonary sacks are more ancient formations. Trachea arose later as organs more adapted to air breathing.

Circulatory system. In spiders, the heart is on the dorsal side of the abdomen.

The excretory system in arachnids is represented by malpighian vessels that open into the intestine or by the kidneys.

The nervous system is formed by the brain and abdominal nervous chain. In spiders, the cephalic ganglia of the nerves merge. Ticks do not have a clear distinction between the brain and the cephalic ganglion, the nervous system forms a continuous ring around the esophagus.

The organs of vision are represented by simple eyes. Spiders usually have 8 eyes. There are organs of chemical sense, organs of touch (sensitive hairs).

Reproduction. Mating crosses occurs at the end of the summer. Immediately after mating, the spider is hastily removed, since the behavior of the spider changes dramatically, sluggish males often become their prey. In the autumn, the female makes a cocoon in which she lays several hundred eggs. She hides the cocoon in a protected place, and perishes herself. In spring, young spiders begin their independent lives.

Diversity. Spider-like species include scorpions, phalanges, spiders, and mites. Some mites are carriers of serious diseases, Zudny mites gnaw through the skin, pollute them, causing a disease of scabies.

Characteristics of Insects

More than 1 million species of animals, which are characterized by the dismemberment of the body into three sections: head, chest and abdomen.

On the head of insects there are:

complex (faceted) eyes, some have simple eyes;

1 pair of antennae (organs of smell);

oral device - communication with the type of food, oral devices can be of various types

On the chest:

two pairs of wings;

three pairs of limbs of different types

On the abdomen:

spiracles (openings of the respiratory system;

in some ovipositorial sting.

Types of oral devices:

gnawing type - beetles, orthoptera, cockroaches, etc. - the most ancient, initial type of mouthpieces;

lizushche-gnawing - the mouth apparatus in bees;

licking mouth apparatus in flies.

butterflies sucking mouthpieces;

piercing-sucking mouthparts at bedbugs, mosquitoes;

Limbs jointed, forming with the help of joints a system of levers. In connection with the lifestyle of the legs are swimming, collective, grasping, jumping, digging and others.

The wings are folds of the cuticle, between the upper and lower layers there is a gap in which the veins with trachea and nerves pass. Wings can be tough (in beetles), scaly (in butterflies), reduced (one pair in flies, two pairs in lice and fleas)

The digestive system begins with the oral apparatus and the oral cavity into which the ducts of the salivary glands open. The anterior intestine includes the pharynx, esophagus, in some insect species there is an extension - goiter. In species that eat solid food, there is a chewing stomach behind the goiter, which contains chitin folds - the teeth that contribute to the chafing of food. The back gut ends with the anus.

On the border between the middle and posterior intestine, the intestinal lumen opens numerous blindly closed malpighiev vessels (up to 200 and more). They absorb decay products from hemolymph.

The respiratory system of insects begins with openings - spiracles, chest and on each abdominal segment. The air through them enters a well-developed system of trachea. Tracheas permeate the entire body of the insect, delivering oxygen directly to each cell.

The heart is on the dorsal side of the abdomen and is a tube. To the heart fit the muscles that ensure its reduction. The hemolymph is colorless, it does not perform the function of transporting gases. Its main function is the transport of nutrients to all organs and metabolic products to the organs of excretion.

The insect nervous system consists of the head ganglion, the subpharyngeal ganglion, and the segmental ganglia of the ventral nerve chain and the nerves extending from them to the senses.

Sense organs. Insects have complex eyes and simple eyes. Complex eyes consist of ommatidia. Some insects have color vision, color perception is shifted towards short-wave rays: they see the ultraviolet part of the spectrum. Mosaic vision. The role of simple ocelli is not fully understood, but it has been proven that they perceive polarized light.

Many insects are capable of making sounds and hearing them. The organs of hearing can be located on the legs of the front legs, at the base of the wings. The olfactory organs are located mainly on the antennas, which are most developed in males. The organs of taste are located not only in the oral cavity, but also on other organs, for example, on the legs - in butterflies, bees, flies, and even on the antennae - in bees and ants. Many insects perceive magnetic fields and their change, but where the organs that perceive these fields are is still unknown.

Reproduction. Insects are dioecious. Many have sexual dimorphism. Males in the abdomen have testes, from which the vas deferens extend, ending with an unpaired ejaculating channel. In females there are two ovaries, they open into the oviducts, which connect to the unpaired vagina below.

When mating, the male seed is injected into the seminal receptacle. In some species, spermatozoa in the seminal receptacle remain alive for several years. In the queen bee, for example, mating flight happens once in a lifetime, and it lives 4-5 years and lays eggs.

In insects, there are cases of parthenogenetic reproduction (without fertilization). Females of aphids during the whole summer lay unfertilized eggs, from which females develop, only in the fall of the larvae both males and males are formed, mating occurs, and fertilized eggs overwinter. Males are formed from parthenogenetic eggs of the public Hymenoptera.

The development of insects is divided into two periods - the embryonic, including the development of the embryo in the egg, and the postembryonic, which begins after the young animal leaves the egg. Postembryonic development occurs with metamorphosis, according to its nature, they are divided into insects with incomplete transformation and insects with complete transformation.

Insects with complete transformation are insects in which the larva differs from the adult, there is a pupal stage during which a global reorganization of the organism takes place (metamorphosis).

The insects with complete transformation include, for example, the orders: Coleoptera, Hymenoptera, Diptera, Lepidoptera, etc.

Detachment Coleoptera. The first pair of wings turned into hard elytra, mouthparts of the gnawing type. In the May beetle, the development of the larvae continues under the ground for several years. The first year the larva feeds on humus, the second - on grass roots, the third - on roots of shrubs and trees, which do great harm to young tree plantations. In the fourth year at the end of spring, the larva turns into a pupa and in the fall a young bug emerges from the pupa. The beetle emerges on the soil surface in the spring of the fifth year.

The larvae of bark beetles, barbel, do great harm to the forest and the garden, damaging the wood of the trees, the Colorado beetle is a dangerous pest of potatoes, which feed on the larvae and adult beetles.

Squad lepidoptera.

Butterflies have a sucking-type mouth apparatus, the wings are covered with scales, which form whimsical patterns. The larvae of butterflies - caterpillars - have a worm-like shape, the mouth apparatus of gnawing type.

There are many species of lepidoptera, whose caterpillars are pests of forests and gardens. Eating leaves, they bring great harm to plants. (hawthorn, cabbage soup, etc)

When visiting flowers, Lepidoptera play a significant role in pollination. The silkworm (unpaired) is used by humans to produce natural silk. Currently, the silkworm - a fully domesticated insect is not found in the wild.

Hymenoptera order

Wings are membranous, two pairs, the second pair is smaller than the first, during flight they are hooked into a single flying surface with the help of hooks. On the head there are a pair of complex faceted eyes and three simple eyes.

Among them are pests (sawflies, horntails, and nut-pots), and species useful for humans. Domestic bees are suppliers of honey, wax, propolis; bumblebees are beautiful pollinators, ants destroy a huge number of harmful insects.

Riders lay their eggs in eggs of other insects, in their larvae. The larvae that came out of them eat their prey, reducing the number of insects harmful to humans. Restraining harmful activity through the use of natural enemies are biological ways of combating.

Order Diptera.  The most highly organized insects, with one pair of wings, the second pair is reduced. Oral devices piercing-sucking or licking.

Diptera is very negative: they are carriers of helminth eggs, as well as causative agents of serious intestinal infections and diseases: tsetse fly - carrier of the causative agent of sleeping sickness, gadfly - anthrax, malaria mosar - malaria.

Gadflies bring great harm to animal husbandry. These large flies lay their eggs in the skin or mucous membranes of livestock. Larvae develop, bringing great torment to their owners.

Do insects with incomplete transformation  the pupal stage is absent, a larva emerges from the egg, resembling an adult insect, but its wings and sex glands are underdeveloped. The larvae molt several times, and winged insects appear after the last molt.

Insects with incomplete transformation include, for example, the orders: Tarakanovye, Dragonflies, Pryvokrylye, Bugs, and others.

Detachment Orthoptera.  Insects of the Grasshopper, Cricket, Medvedka and Locust families are the best known of this order. Legs jumping or digging type, gnawing mouth apparatus.

Certain locust species cause great damage to agriculture, destroying crops on hundreds of hectares. Beardies, often damaging the underground organs of plants, cause significant damage.

New concepts and terms:  external skeleton, antennas, antennulae, cephalothorax, facet eyes, chelicerae, pedipalps, oral apparatus, extraorganismal digestion, malpighian vessels, spider wart, trachea, metamorphosis (complete, incomplete),

Questions on the consolidation

· What signs of Arthropods allowed them to occupy a dominant position on Earth among invertebrates?

· Establish the sequence in which the enumerated classes of animals have arisen: polychaetes, insects, crustaceans, sarcodes, bivalves, ciliary worms

· Do the egg, the caterpillar, the pupa, and the adult insect of a lemnica insect have the same or different genotypes? Explain the answer.

· What role can the web play in the life of various invertebrates?

· Who is the causative agent of the disease: malaria, encephalitis, scabies? Ways to spread them.

· Both the vertebrate and invertebrate animals have mastered the terrestrial-living environment. What are the similar features of their adaptability to life on land? What are the differences?

Chord type

Initial level of knowledge:

kingdom, type, heterotrophs, aerobes, bilateral symmetry, embryonic period, whole, cavity, tissue, organ, organ system, skeleton, skull, closed circulatory system, heart, intestine (front, middle, back intestine), digestive glands, larva, metamorphosis.

Spiders - a special class of living creatures, which was named after the girl from Greek mythology. In the myth of a weaver named Arahna, who dared to challenge Athena to a contest in skill, it is said that the goddess overcame without recognizing the efforts of an ordinary girl. From resentment and frustration Arachna wanted to hang herself. But by Athena she was transformed into a spider, without getting tired of weaving her web.

And now we will see in more detail some properties of these arthropods. What features of the structure and behavior of the spider krestovik help these living creatures to survive?

The special life of spiders

The cross spider (photo confirms) is an ordinary representative of its own class. To the squad   arachnids also include mites and scorpions. More than 300,000 species of this class live in tropical and mixed forests of our planet. To find out what features of the structure and behavior of the spider-cross there, you must be a very attentive observer. In most cases, the "weaver" itself is invisible to us. But its network is fully visible!

The behavior of the spider-krestovik is based on its way of life and habitat. Forests, parks, gardens and various green spaces are all home to this species. In human housing, too, quite often you can meet araneusa diadematus.

Description of the appearance of the spider krestovik

The bodies of all spiders are similar:

• small head;
• large abdomen ovoid;
• 8 legs.

By drawing on the surface of the back, similar to a cross, this species received its name. The so-called eyes (8 pairs of pieces) are placed in the frontal part of the head of the spider. The mouth of the small cross consists of several “details”: a pair of claw-jaws with poisonous glands on the bases, and also leg loops (chelicera) - organs of touch.

The structural features of the spider spider allow it to survive, attack and feed with the help of its own massive jaws. On the legs are placed comb claws, with which the “forest weaver” makes its sticky net. Web warts are low abdomen. Despite the presence of so many eyes, the spider family sees very badly. The main assistant for survival is touch through sensitive feet.

The power of the cross

The builder and the hunter, the krestovik spider feeds on everything that falls into its traps. It can be gadflies and flies, mosquitoes or various midges and small insects. All representatives of this species are predators, including the cross. The photo helps to see the process of catching insects in a sticky network network. Grasping the prey by the pelvis, with its jaws-hooks, the spider bites through it, injecting paralyzing poison into the wound of the victim. Immediately in his little body enters the digestive juice, softening the insides of the fly.

With his insatiable appetite, this insect hunter is able to suck more than 10 flies at a time. If there are a lot of victims, the behavioral characteristics of the spider-yoke give a tip to him to wrap up the captives in a cocoon and throw them “for later” Supplies are hung from the trap on the yarn. Spiders are not adapted to eating hard food. But they can suck the softened entrails of insects. For such an extraintestinal method of feeding the arachnids do not need stomachs.

How spiders breed

Only at the end of the summer period do the octopus forest dwellers achieve maturation. Watching what features of the structure and behavior of the cross-spider contribute to the reproduction of this species, biologists have learned that females are more than twice as large as males. Living alone, only to the fall the spider goes away to find for himself a "lady." Attaching his thread to the trap of the female and tugging at it, he specifically draws the attention of the female to himself. The pairing that takes place becomes the last event in the life of the male - the “lady” eats him after the insemination process. The instinct of saturation, nothing personal!

The eggs are laid by the female spider in the autumn months, wrapping the clutch in a dense filament cocoon. With such silk protection, the future offspring will simply survive any frosts. Hanging in hidden places, in the crevices of tree bark, these cocoons will open later in the spring. Small spiders, after wintering, will come out to build their own traps.

What makes a spider weave a web

Without its own luxurious trap, this predator would not be a spider. Let's look at what features of the structure and behavior of the spider-spider force it to weave a web for life and nutrition.

• Hunger - the root cause of all the actions of representatives of this type. To have food, it is necessary to find a place suitable for a trap.
• When the arthropod is determined with the territory, the next instinct is cut in - the spider composition begins to stand out.
• Each action causes the following signals about the desired continuation. Everything is arranged simply and correctly.

The abilities of a spider in weaving a fishing net can be innate, embedded in the genetic code, or acquired, depending on the living environment. But the overall network layout always has many similar details. Completely woven spiral coils are fixed along the radii of the network with equal angles. With all this, the center of mass always coincides with the center of the arachnoid grid.

About spiders, web and human

Remembering the signs and research, you can find out what features of the behavior and structure of the cross-spider used the world's population to heal various diseases.

• By applying the freshest spider web to a small wound, you can stop the blood.
• It is believed that the decoration with the image of the forest octopod brings currency fortune.
• European medieval healers claimed that wearing a pendant in the form of a spider on the chest would protect against diseases.
• If the "handsome" sits in the very center of his own trap and does not crawl out, then it will definitely rain.
• If the spiders weave the freshest webs, then it is to sunny weather.

In conclusion about the usefulness of the order of arachnids

If it were not for this family, the population of the earth could once a year suffer huge losses from
crop loss. Spiders actually play a leading role in the fight against pests. Over a season, more than 200 kg of probable carriers of various infectious diseases are destroyed on a hectare of forest area by these gluttons.

Viva spider-krestovikam!