General characteristics of the class Arachnida (Arachnida) Subtype Chelicerata (Chelicerata), Class Arachnida (Arachnida) From crustaceans, chelicerae differ in the absence of antennules on the head lobe and the presence of two pairs of mouth limbs: chelicerae and leg tentacles, or pedipalps. The remaining four pairs of walking legs. Thus, arachnids have 6 pairs of limbs.
General characteristics of the class Arachnida (Arachnida) The class Arachnida unites about 63 thousand species of animals, the most important orders are spiders and ticks. The body of spiders consists of the cephalothorax and abdomen; in ticks, all parts of the body are fused. Covers. In arachnids, they bear a relatively thin chitinous cuticle, under which lies the hypodermis.
General characteristics of the class Arachnida (Arachnida) The cuticle protects the body from loss of moisture during evaporation, so the arachnids inhabited the most arid regions of the globe. The strength of the cuticle is given by proteins that encrust chitin. The degree of dismemberment of the body is different: some segments of the chest may be free (solpugs), but more often fused, the abdomen can also be dissected (scorpions) or fused (spiders).
General characteristics of the Arachnida class The digestive system is typical, represented by the anterior, middle and hindgut. The mouthparts are different, depending on the nature of the food. In the middle intestine, which has blind outgrowths, the ducts of the digestive gland of the liver open.
General characteristics of the class Arachnida (Arachnida) Respiratory organs. Some respiratory organs have lung sacs, others have tracheae, and others have both at the same time. Some small arachnids, including some mites, have no respiratory organs; breathing is carried out through thin covers. Lung sacs are more ancient formations. It is believed that the gill limbs plunged into the body, thus forming a cavity with lung leaflets. The tracheae arose independently and later than them, as organs more adapted to air breathing.
General characteristics of the class Arachnida (Arachnida) Circulatory system. In spiders, the heart is located on the dorsal side of the abdomen, has ostia openings (3-4 pairs), and in ticks, the heart turns, at best, into a sac with one pair of ostia, or is reduced.
General characteristics of the class Arachnida The excretory system in arachnids is represented by malpighian vessels that open into the intestine between the middle and hindgut. In addition to the Malpighian vessels, some arachnids also have coxal glands, paired sac-like formations lying in the cephalothorax. Convoluted canals depart from them, ending with the bladders and excretory ducts, which open at the base of the limbs.
General characteristics of the class Arachnida (Arachnida) The nervous system is formed by the brain and the abdominal nerve chain. In spiders, the cephalothoracic ganglia are fused. In ticks, there is no clear distinction between the brain and the cephalothoracic ganglion; the nervous system forms a continuous ring around the esophagus.
General characteristics of the class Arachnida (Arachnida) The organs of vision are represented by simple eyes found in most arachnids. Spiders usually have 8 eyes. There are chemical sense organs, organs that register mechanical, tactile stimuli, which are perceived by differently arranged sensitive hairs. The organs of hearing are poorly developed.
General characteristics of the class Arachnida (Arachnida) Reproduction and development. Arachnids have separate sexes. Fertilization is internal, followed in primitive cases by spermatophoric insemination or, in more advanced cases, by copulation. The spermatophore is a sac secreted by the male, which contains a portion of the seminal fluid, protected by a cobweb from drying out during exposure to air. The female captures it and places it in the genital tract.
Order Spiders (Aranei) 27 thousand species. External building. A typical representative of the detachment is the cross-spider. The female is larger than the male, she 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 of the cephalothorax and abdomen. Antennae are absent, eight simple eyes are located in two rows on the anterior part of the cephalothorax.
Detachment Spiders (Aranei) There are six pairs of limbs on the cephalothorax: jaws (chelicerae), leg tentacles (pedipalps) and four pairs of walking legs. At the base of the chelicerae are poisonous glands, the ducts of which open at the tips of the claws. With chelicerae, spiders pierce the covers of victims and inject poison into the wound. Males have a copulatory apparatus with a reservoir on the terminal segment of the pedipalps, which the male fills with seminal fluid and, during copulation, injects the seminal fluid into the female's seminal receptacle.
Order Spiders (Aranei) There are no limbs on the abdomen, there are a pair of lung sacs, two bundles of tracheae and three pairs of spider warts. There are about 1000 spider glands in the abdominal cavity, which produce various types of cobwebs - dry, wet, sticky, etc. Different types of cobwebs perform different functions, one for catching prey, the other for building a dwelling, the third is used in the formation of a cocoon. On cobwebs, young spiders settle.
Detachment Spiders (Aranei) The web at the cross is located vertically, on the radial threads there are numerous turns of spiral threads. The spider itself hides in a secluded corner, and when the prey enters the network, the vibrations of the network are transmitted to the spider via a signal thread. Covers. Chitinized cuticle formed by the hypodermis. It is a lightweight and durable exoskeleton. The body cavity is a mixed mixocoel. Digestive system. This is where the so-called extraintestinal digestion takes place.
With the help of the sucking stomach, partially digested food enters the midgut, which has long blind lateral protrusions that increase the absorption area and serve as a place for temporary storage of the food mass. The ducts of the liver (four hepatic appendages) also open here. It secretes digestive enzymes and serves to absorb nutrients.
Detachment Spiders (Aranei) The circulatory system is not closed. The heart is located on the dorsal side of the abdomen, has 3 pairs of ostia. The anterior aorta arises from the anterior end of the heart. The hemolymph enters the system of cavities, then washes the lung sacs, from there to the pericardium, and then through the ostia to the heart. The hemolymph of arachnids contains a blue respiratory pigment called hemocyanin containing copper.
Order Spiders (Aranei) The excretory system is represented by the coxal glands (in young animals), the ducts of which open in the segment of the first walking limbs, and the Malpighian vessels. Grains of guanine, the main excretory product of arachnids, are excreted from the Malpighian vessels into the intestine. Guanine has low solubility and is removed from the body in the form of crystals. This retains moisture and is important for animals that have moved to life on land.
Detachment Spiders (Aranei) Nervous system. In spiders, a further concentration of the nervous system is observed, the brain is formed by the merged ganglia of the head and chest, a large knot is located in the abdomen. Vision is poor, hearing organs are poorly developed, represented by auditory vesicles. Well-developed organs of balance (statocysts), touch.
Order Spiders (Aranei) Reproduction. Mating of crosses occurs at the end of summer. The spider's eyesight is weak, the male needs to be very careful so that the female does not mistake him for prey. Immediately after mating, the spider is hastily removed, as the behavior of the spider changes dramatically, slow males are often killed and eaten. In autumn, the female makes a cocoon from a special web, in which she lays several hundred eggs. She hides the cocoon in a fairly protected place, and she herself dies. In the spring, young spiders begin an independent life.
Order Spiders (Aranei) Variety. Of the 1000 species of spiders in Europe, only one species of tarantula is dangerous to humans. This is a large (34 cm) spider that lives in vertical burrows, the walls and entrance of which it braids with cobwebs. Its bite causes local inflammation, like a bee sting.
Order Spiders (Aranei) In Central Asia, in the Caucasus, in Kazakhstan and in the Crimea, the karakurt spider, deadly to humans, cattle, horses and other animals, lives. But sheep are completely immune to the poison of karakurt. Translated from Turkic, karakurt is “black death”. The poison of the karakurt is 15 times stronger than the poison of a rattlesnake, the bite causes severe poisoning and can be fatal. But if the bitten place is not later than two minutes later, until the poison has had time to be absorbed into the blood, to burn with a flammable match head, then the poison is destroyed.
Detachment Ticks (Acari) This order includes about species of small arachnids in length from fractions of millimeters to 2-3 centimeters. In this group, there is a tendency to merge all parts of the body, in many the body is not divided into the cephalothorax and abdomen, all parts of the body are merged. The development of ticks occurs with metamorphosis: a six-legged larva emerges from the egg, which, after a series of molts, turns into an eight-legged immature nymph, and that into an adult, into the stage of an adult animal. Usually development occurs with the change of several owners.
Order Ticks (Acari) Taiga tick, dog tick, pasture ticks are carriers of pathogens of agricultural animals: piroplasmosis of mammals, spirochetosis of chickens, geese, ducks. Ticks carry pathogens and such human diseases as taiga encephalitis, tick-borne typhus, tularemia, etc. Diseases, the pathogens of which are transmitted by carriers, are called transmissible.
Detachment Ticks (Acari) In the years, a team of scientists under the general guidance of Academician E.N.
1. The class Arachnida combines more than (_) species of animals. 2. The cephalothorax carries (_) pairs of limbs. 3. Ticks have a body (_). 4. On the abdomen of arachnid limbs (_). 5. The first pair of limbs of the cephalothorax is called (_), consists of 2-3 segments, ends with a hook, claw or stylet. 6. The second pair of limbs is called (_) and are used as: walking legs, organ of touch, lower jaw, claws for grabbing food, as a copulatory apparatus. 7. Walking legs - (_). 8. The spider's saliva contains enzymes, with the help of which digestion occurs outside the spider's body - (_) digestion. 9. The respiratory organs of the cross spider - (_) 10. The excretory system is represented by (_), which open in (_). 11. Development in spiders (_). 12. More than (_) thousand species of spiders are known, ticks - (_) thousand species. 13. Mouth apparatus of ticks (_) or (_). Repetition
1. How many species are in the Arachnida class? 2. What antennae are on the cephalothorax of a spider? 3. How many and what kind of eyes are on the cephalothorax of a cross spider? 4. How many and what kind of limbs does a cross spider have? 5. What organs open into the intestines of the cross? 6. Where does digestion take place in the cross? 7. What features in the structure of the midgut increase its absorption surface? 8. In what part of the body is the heart of the cross? 9. What kind of blood enters the heart of the cross? 10. What are the respiratory organs of the cross? 11. What are the excretory organs of the cross? 12. What is the main product of protein metabolism in arachnids? 13. What are the features of the nervous system of the cross? 14. What is the fertilization of spiders? 15. What is the development of spiders? 16. In which representatives of arachnids, the head, chest and abdomen merged into one?
Biology lesson on the topic "Class of arachnids". 7th grade
Biology teacher: Kriulina I.V.
Goals:
Educational: To acquaint students with the diversity and lifestyle of arachnids, the features of the structure and life activity that allowed them to become one of the first settlers of land, their significance in nature and human life.
Developing: Contribute to the continuation of the formation of skills in working with tests for further preparation for the GIA and OGE, working with reference signals
Educational: To teach respect for nature, showing that each organism has its own place in the ecosystem, significance in nature and human life, its own unique history and originality.
Equipment: Table "Crustaceans", "Arachnids", reference signals, cards, tests on sheets
During the classes
I. Knowledge Test
- Where does cancer live, what are the features of adaptability to the environment in its external structure, behavior, reproduction.
- What are the features of the internal structure?
- Digestive system. (Intestines in crustaceans usually with a chewing stomach and a "liver" opening into the midgut.) Why and how can a crustacean stomach chew?
Why are there crayfish that have one claw smaller than the other? (The claw of cancer can come off during a fight with the enemy or during an unsuccessful molt. Then it grows again (regenerates), but it turns out to be smaller).
- Respiratory, circulatory system. Why can crayfish taken out of the water stay alive for several days? (Thanks to the lateral edges of the shell, which protect the gills from drying out. As long as the gills of the crayfish are in a wet state, the crayfish do not die).
- Excretory, nervous system.
- Reproduction.
- What is the importance of crustaceans in nature and human life?
Biological dictation (All students answer in notebooks, followed by verification)
1. Cancer breathes with gills (Yes).
2. Cancer is diurnal (No).
3. The body of cancer consists of two sections (Yes).
4. Cancer has simple eyes (No).
5. Crayfish are herbivorous (No).
6. Cancer always moves backwards (No).
7. Cancer is characterized by claw regeneration (Yes).
8. With the help of walking legs, the crayfish moves along the bottom (Yes).
9. The circulatory system of cancer is not closed (Yes).
10. The mobility of the eyes of Cancer compensates for the immobility of the head (Yes).
11. Cancers are "orderlies" of reservoirs (Yes).
12. Cancer grabs food with its jaws and sends it to the mouth (Yes).
13. The abdomen of cancer consists of 10 segments (No).
14. Claws are organs of defense, attack, food capture (Yes).
15. The blood of cancer is red (No).
16. Cancer females lay eggs in winter (Yes).
17. Crayfish live up to 50 years (No).
II. Learning new material
- Let's list again 3 classes from the type of Arthropods that we study: Crustaceans; arachnids; Insects.
What are the arachnids called in Latin? (Arachnida).
– And who knows why?
- The famous naturalist d "Orbigny in pantaloons from the web of Brazilian spiders flaunted at one time. He wore them for a long time, but they did not wear out. And Louis XIV, King of France, the parliament of the city of Montpellier somehow presented stockings and gloves woven from silky threads as a gift French spiders.
“It is well established that cobwebs stop bleeding. Just take it fresh and clean.
- What is the spider itself, the owner of the web?
- The task of our lesson: to find out not only the structure of spiders using the example of a cross, but also to talk about which arthropods are included in the class Arachnids, what role they play in nature and human life. Recording the topic: "Class Arachnids."
The class Arachnida includes up to 62,000 species.
These are haymakers, ticks, spiders, scorpions, etc. All of them are terrestrial animals, except for the silver spider. Many weave webs.
What is common to all arthropods? (Limbs, chitinous cover). The body consists of 2 sections - the cephalothorax and the abdomen. The abdomen is separated from the cephalothorax by constriction. They do not have antennae and compound eyes. There are 4 pairs of legs on the cephalothorax.
Also several pairs of simple eyes; and below the jaw - chelicerae. The spider grabs its prey with them. Inside there is a channel with poison. There are short hairy tentacles, or pedipalps (organs of touch).
From the bottom on the abdomen are arachnoid warts that produce cobwebs. These are modified abdominal legs. (What does this say?) - About ancestors who had legs for movement. On its hind legs there are comb-like claws that help to pull the web threads from the glands and collect them into one.
The thread is made of protein. From the web warts of one spider, up to 4 km of web can be pulled out. They need the web to catch prey, to make cocoons, to protect the eggs from adverse effects. Therefore, it can be of several varieties: dry, wet, sticky, corrugated. It serves for different purposes. The web is thinner and stronger than the threads of the silkworm caterpillar.
But the industrial production of such threads cannot be established, because. spiders are very gluttonous and you will not get enough of flies, and the climate is not suitable everywhere.
A spider weaves a trapping web from cobweb threads. First, a frame with rays converging towards the center, then a long, thin and very sticky thread, placing it in the center of the spiral. (The mass of a web, equal in length to the equator of the globe, is 340 g.)
Then, in anticipation of prey, he sits near the net in a hidden nest made of cobwebs. A signal thread is stretched from the center of the network to it.
- Observations of the behavior of a spider show that it jumps out of its hiding place, quickly moves towards a fly only if there is a medium-sized fly: if a small fly hits, then the spider does not pay attention to it. How does a spider know the size of its prey?
The circulatory system is like a crayfish. Which?
- Unclosed. Hemolymph. The heart looks like a tube or a double rhombus
Respiratory system. The spider breathes atmospheric air. It has a pair of lung sacs lined with blood vessels, and tracheal bundles, tubes that run through the animal's body.
Working with the tutorial drawing (p. 123)
excretory system. Tubules are Malpighian vessels. At one end they collect metabolic products, and at the other they flow into the intestines. Water is absorbed in the intestines. Therefore, spiders save water and can do without it (a vicious circle of water consumption).
Nervous system. As in crayfish, only the thoracic nodes and the supraesophageal node are developed.
breeding system. Separate animals. Fertilization in the body of a female. The female lays eggs openly, or braids them with a cobweb (cocoon).
There are 62,000 species of arachnids in nature.
We will meet some representatives, as they live in our area and are very dangerous.
- Karakurt (its poison is 15 times stronger than the poison of a rattlesnake).
- Tarantula.
- Scorpio (found in Central Asia, in the Caucasus, in the Crimea).
- The tarantula (its digestive juice dissolves 3 g of mouse tissues weighing 20 g per day).
- Hayman.
- Silver (
– In addition to Spiders, ticks also belong to Arachnids (messages
How are mites similar to spiders?
- What is the difference?
- Which mite reduces the yield of fruit and melon crops?
A - taiga, B - scabies, C - canine, D - cobweb.
What mites are harmful to human health?
A - soil, B - scabies, C - canine, D - cobweb.
Did you know that kings and Popes of Rome, and great scientists died from scabies in ancient times: Herodotus, Philip II and Pope Clement VII.
Are arachnids necessary in nature?
- If there were no spiders, people could die from various diseases, as they are carried by flies, and as scientists calculated, armed with a microscope, there are 26,000,000 microbes on the body of one fly.
- They are food for the birds.
Some are harmful to plants, animals and humans.
- They are carriers of diseases.
- Participate in soil formation.
“And once the spiders helped the French defeat Holland.
So, the general signs of arachnids:
Mostly terrestrial species;
4 pairs of walking legs;
Predators => adaptable, venom glands, spider warts;
Body length from 0.1 mm to 12 cm.
III. Consolidation of knowledge
Given syllables: PA SE NO KA RA SCOR UK KO SETS KURT PION
Make up the names of arachnids from them.
(spider, haymaker, karakurt, scorpion)
IV. Homework.
Presentation for a biology lesson on the topic: Presentation for a biology lesson on the topic: Class Arachnids Grade 7 MKOU "Mosalskaya OOSh" Biology teacher Ershova I.F. Repetition of signs of the Crustacea class. Repetition of features of the class Crustaceans.
- 1. What departments does the body of crustaceans consist of?
- 2. What organs are located on the cephalothorax?
- 3. External structure of the abdomen of cancer.
- 4. How many walking legs does cancer have?
- 5. What is the body of crustaceans covered with?
- 6. Why does cancer shed?
- Leg tentacles - organs of touch
- Walking legs - 4 pairs
- Chelicera - hard jaws
- Spider warts produce cobwebs
Variety of spiders
The largest spider in the world lives in tropical forests. This creature is called Theraphosa Blond or simply the tarantula Goliath. The length of the body reaches nine centimeters, and the span of the limbs is 26-28 centimeters. In other words, such a spider can be the size of a dinner plate.
- The largest spider in the world lives in tropical forests. This creature is called Theraphosa Blond or simply the tarantula Goliath. The length of the body reaches nine centimeters, and the span of the limbs is 26-28 centimeters. In other words, such a spider can be the size of a dinner plate.
- 1. Chest and abdomen fused
- 2.Small sizes
- 3. Larvae have 3 pairs of legs
- 4. Mouth parts adapted for piercing and sucking
How can you protect yourself from tick-borne encephalitis?
The use of special protective suits or adapted clothing that should not allow ticks to crawl. The shirt should have long sleeves, which are reinforced at the wrists with an elastic band. They tuck the shirt into trousers, the ends of the trousers into socks and boots. The head and neck are covered with a scarf.
Preventive vaccinations against tick-borne encephalitis
Thank you for your attention Reflection The following sources were used in the presentation: O.V. Voltsit, M.E. Chernyakhovsky Encyclopedia "Nature of Russia" http://spidersworld.ru/ http://www.zoopicture.ru/tag/pauk/
Subject: biology
Teacher: Talitskikh Marina Vladimirovna
Educational institution: MBOU - secondary school, Vesele village, Mozdok district
Theme: "Arachnids"
Basic provisions to the topic:
1. - Class Arachnids.
- Representatives of arachnids are eight-legged land arthropods, in which the body is divided into a cephalothorax and abdomen, connected by a thin constriction or fused.
- Arachnids do not have antennae.
- Six pairs of limbs are located on the cephalothorax - chelicerae, leg tentacles and four pairs of walking legs. There are no legs on the abdomen. Their respiratory organs are lungs and trachea.
- The eyes of arachnids are simple. Arachnids are dioecious animals.
- The body length of various representatives of this class is from 0.1 mm to 17 cm. They are widely distributed around the globe. Most of them are land animals. Among ticks and spiders there are secondary water forms.
- The class of arachnids includes up to 60 thousand species.
2. The external structure and lifestyle of spiders- rice. 91 p. 120
- cross spiders(so named for the cross-shaped pattern on the dorsal side of the body) can be found in the forest, garden, park, on the window frames of suburban and village houses. Most of the time, the spider sits in the center of its trapping web of sticky thread - cobwebs.
- The body of the spider consists of two sections: the cephalothorax and the spherical abdomen. The abdomen is separated from the cephalothorax by a narrow constriction. At the anterior end of the cephalothorax are four pairs of eyes, and at the bottom are hook-shaped hard jaws - chelicerae. With them, the spider grabs its prey. There is a canal inside the chelicerae. Through it, poison from the poisonous glands located at the base of the chelicerae enters the body of the victim. Next to the chelicerae are short, covered with sensitive hairs, the organs of touch - the leg tentacles. Four pairs of walking legs are located on the sides of the cephalothorax.
- The body is covered with a light, strong and rather elastic chitinous cuticle. Like crayfish, spiders periodically molt, dropping their chitinous cover. At this time they are growing.
- At the lower end of the abdomen there are three pairs of arachnoid warts that produce cobwebs - these are modified abdominal legs.
- In a spider, as in crustaceans, the body cavity has a mixed nature - in the course of development it arises when the primary and secondary body cavities are connected.
3. Digestive system
- The cross spider cannot eat solid food. Having caught prey, such as some kind of insect, with the help of a web, he kills him with poison and lets digestive juices into his body. After some time, the contents of the caught insect liquefies, and the spider sucks it out. Only the chitinous shell remains of the victim. This type of digestion is called extraintestinal.
- The digestive system of a spider consists of a mouth, pharynx, esophagus, stomach, and intestines. In the midgut, long blind outgrowths increase its volume and absorption surface. Undigested residues are brought out through the anus.
4. Respiratory system.
- The respiratory organs of a spider are the lungs and trachea. Lungs or lung bags are located below the abdomen, in front of it. These lungs evolved from the gills of distant ancestors of aquatic spiders. The spider-cross has two pairs of non-branching tracheas - long tubes with special spiral chitinous thickenings inside. They are located in the back of the abdomen.
5. Circulatory system
- spiders are open.
Heart has the form of a long tube located on the dorsal side of the abdomen. Blood vessels branch off from the heart. Like crustaceans, spiders have hemolymph circulating in their bodies.
6. excretory system
- It is represented by two long tubes - Malpighian vessels.
- With one end, the Malpighian vessels blindly end in the body of the spider, with the other they open into the posterior intestine. Through the walls of the Malpighian vessels, metabolic products are removed, which are then brought out. Water is absorbed in the intestines. That. spiders conserve water, so they can live in dry places.
7. Nervous system
- The spider consists of the cephalothoracic node and numerous nerves extending from it.
8. Reproduction.
- Fertilization in spiders is internal. The male carries the spermatozoa into the female genital opening with the help of special outgrowths located on the front legs. After a while, the female lays eggs and wraps them in cobwebs. This is how you get a cocoon.
- The eggs develop into small spiders. In autumn, they release cobwebs, and on them, like on parachutes, they are carried by the wind over long distances - resettlement takes place.
9. Variety of arachnids
Ë Spiders
Ë Haymakers
Ë Scorpions
Ë Ticks
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