Arachnids general characteristics presentation. Internal structure of arachnids
General characteristics of the class Arachnida (Arachnida) Subtype Chelicerata, Class Arachnida (Arachnida) Chelicerates differ from crustaceans by the absence of antennules on the head lobe and the presence of two pairs of oral limbs: a chelicerae and leg tentacles, or pedipalps. The remaining four pairs of walking legs. Thus, arachnids have 6 pairs of limbs.
General characteristics of the Arachnida class The Arachnida class unites about 63 thousand species of animals, the most important orders being spiders and mites. The body of spiders consists of a cephalothorax and abdomen; in mites, all parts of the body are fused. Veils. In arachnids, they bear a relatively thin chitinous cuticle, under which lies the hypodermis.
General characteristics of the class Arachnida The cuticle protects the body from loss of moisture through evaporation, which is why arachnids have populated the driest regions of the globe. The strength of the cuticle is given by proteins encrusting chitin. The degree of dismemberment of the body varies: some segments of the chest can be free (solpugi), but more often fused, the abdomen can also be dismembered (scorpions) or fused (spiders).
General characteristics of the class Arachnida Digestive system typical, represented by the foregut, middle and hindgut. Mouthparts different, depending on the nature of the food. The ducts of the digestive gland of the liver open into the midgut, which has blind processes.
General characteristics of the class Arachnida. Respiratory organs. Some have respiratory organs with pulmonary sacs, others with tracheas, and still others with both at the same time. Some small arachnids, including some ticks, do not have respiratory organs; breathing occurs through thin integuments. Pulmonary sacs are more ancient formations. It is believed that the gill limbs sank into the body, thereby forming a cavity with pulmonary leaves. Tracheas arose independently and later than them, as organs more adapted to air breathing.
General characteristics of the class Arachnida Circulatory system. In spiders, the heart is located on the dorsal side of the abdomen, has ostial openings (3-4 pairs), and in ticks the heart turns into best case scenario into a pouch having one pair of ostia, or reduced.
General characteristics of the class Arachnida Excretory system in arachnids it is represented by Malpighian vessels, which open into the intestine between the midgut and hindgut. In addition to the Malpighian vessels, some arachnids also have coxal glands, paired sac-like formations located in the cephalothorax. Convoluted channels extend from them, ending bladders and excretory ducts, which open at the base of the limbs.
General characteristics of the class Arachnida Nervous system formed by the brain and the ventral nerve cord. Spiders have cephalothorax nerve ganglia merge. In ticks there is no clear distinction between the brain and the cephalothoracic ganglion; the nervous system forms a continuous ring near the esophagus.
General characteristics of the class Arachnida The organs of vision are represented by simple eyes, found in most arachnids. Spiders most often have 8 eyes. There are organs of chemical sense, organs that register mechanical, tactile irritations, which are perceived by differently arranged sensitive hairs. The hearing organs are poorly developed.
General characteristics of the class Arachnida. Reproduction and development. Arachnids are dioecious. Fertilization is internal, accompanied in primitive cases by spermatophore insemination or in more developed cases by copulation. The spermatophore is a sac secreted by the male, which contains a portion of seminal fluid, protected by the web from drying out while exposed to air. The female captures it and places it in the reproductive tract.
Order Spiders (Aranei) 27 thousand species. External building. A typical representative of the order 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, the cephalothorax and abdomen. There are no antennae; on the front of the cephalothorax there are eight in two rows. simple eyes.
Order Spiders (Aranei) The cephalothorax has six pairs of limbs: jaws (chelicerae), claws (pedipalps) and four pairs of walking legs. At the base of the chelicerae there are poisonous glands, the ducts of which open at the tips of the claws. Spiders use chelicerae to pierce the integument of their victims and inject poison into the wound. In males, on the terminal segment of the pedipalp there is a copulatory apparatus with a reservoir, which the male fills with seminal fluid and injects during copulation seminal fluid into the spermatheca of the female.
Order Spiders (Aranei) There are no limbs on the abdomen, there are a pair of pulmonary sacs, two bundles of tracheae and three pairs of arachnoid warts. In the abdominal cavity there are about 1000 arachnoid glands that produce various types cobwebs: dry, wet, sticky, etc. Different types webs perform various functions, one for catching prey, the other for building a home, the third is used in the formation of a cocoon. Young spiders settle on cobwebs.
Order Spiders (Aranei) The web of 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 falls into the net, the vibrations of the net are transmitted to the spider along a signal thread. Veils. Chitinized cuticle formed by the hypodermis. It is a lightweight and durable exoskeleton. Body cavity mixed myxocoel. Digestive system. This is where 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 food mass. The liver ducts (four hepatic appendages) also open here. She highlights digestive enzymes and serves to absorb nutrients.
Order Spiders (Aranei) The circulatory system is not closed. The heart is located on the dorsal side of the abdomen and has 3 pairs of spines. The anterior aorta arises from the anterior end of the heart. Hemolymph enters the system of cavities, then washes the pulmonary sacs, from there into the pericardium, and then through the ostia into the heart. The hemolymph of arachnids contains respiratory pigment blue hemocyanin containing copper.
Order Spiders (Aranei) The excretory system is represented by coxal glands (in young animals), the ducts of which open in the segment of the first walking limbs, and Malpighian vessels. From the Malpighian vessels, grains of guanine, the main excretory product of arachnids, are released 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 transitioning to life on land.
Order Spiders (Aranei) Nervous system. In spiders, a further concentration of the nervous system is observed, the brain is formed by fused ganglia of the head and chest, a large node is located in the abdomen. Vision is poor, hearing organs are poorly developed, represented by auditory vesicles. The organs of balance (statocysts) and touch are well developed.
Order Spiders (Aranei) Reproduction. Mating of crosses occurs at the end of summer. The spider's eyesight is poor; the male needs to be very careful so that the female does not mistake him for prey. Immediately after mating, the spider hastily leaves, 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, into which she lays several hundred eggs. She hides the cocoon in a fairly protected place, and she dies. In spring, young spiders begin an independent life.
Order Spiders (Aranei) Diversity. Of the 1,000 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 weaves with cobwebs. His bite causes local inflammation like a bee sting.
Squad Spiders (Aranei) Central Asia, in the Caucasus, Kazakhstan and Crimea lives a deadly large cattle, horses and other animals karakurt spider. But sheep are completely immune to karakurt poison. Translated from Turkic karakurt means “black death”. Karakurt venom is 15 times stronger than the venom of a rattlesnake; a bite causes severe poisoning and can be fatal. But if the bitten area is burned with a flammable match head no later than two minutes, before the poison has had time to be absorbed into the blood, then the poison is destroyed.
Order Ticks (Acari) This order includes about species of small arachnids ranging 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 fused. 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 imago, into the stage of an adult animal. Typically, development occurs with a change of several hosts.
Order Ticks (Acari) Taiga tick, dog tick, pasture ticks are carriers of pathogens of farm animals: mammalian piroplasmosis, spirochetosis of chickens, geese, ducks. Ticks also carry pathogens of human diseases such as taiga encephalitis, tick-borne typhus, tularemia, etc. Diseases whose pathogens are transmitted by vectors are called vector-borne.
Order Ticks (Acari) Over the years, a team of scientists under general management Academician E.N. Pavlovsky managed to find out that the carriers of the virus tick-borne encephalitis are taiga ticks, and natural reservoir Chipmunks and some other species of mammals are used for this pathogen.
1. The Arachnida class includes more than (_) species of animals. 2. The cephalothorax bears (_) pairs of limbs. 3. Ticks have a body (_). 4. On the abdomen of arachnids there are 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 is used as: walking legs, an organ of touch, lower jaw, claws for capturing food, as a copulatory apparatus. 7.Walking legs – (_). 8. Spider saliva contains enzymes with the help of which digestion occurs outside the spider’s body - (_) digestion. 9. The respiratory organs of the cross spider are (_) 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. Oral apparatus of ticks (_) or (_). Repetition
1. How many species are there in the Arachnida class? 2.What antennae are on the spider’s cephalothorax? 3. How many and what kind of eyes are there on the cephalothorax of the cross spider? 4. How many and what kind of limbs does a cross spider have? 5.What organs open into the intestine 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 secreted in arachnids? 13.What are the features of the nervous system of the cross? 14.What is fertilization like in spiders? 15.What is the development of spiders? 16.Which representatives of arachnids have the head, chest and abdomen merged into one?
Presentation for a biology lesson on the topic: Presentation for a biology lesson on the topic: Class Arachnids 7th grade MCOU "Mosalskaya secondary school" Biology teacher Ershova I. F. Repetition of signs of the class Crustaceans. Repetition of characters of the class Crustaceans.
- 1. What parts does the crustacean body consist of?
- 2.What organs are located on the cephalothorax?
- 3. External structure of the abdomen of the crayfish.
- 4. How many walking legs does cancer have?
- 5.What is the body of crustaceans covered with?
- 6.Why does crayfish shed?
- Tentacles - organs of touch
- Walking legs – 4 pairs
- Chelicerae - hard jaws
- Spider warts produce webs
Variety of spiders
Most big spider in the world lives in tropical forests. This creature is called Teraphosa Blonda 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 Teraphosa Blonda 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 are adapted for piercing and sucking
How can you protect yourself from tick-borne encephalitis?
The use of special protective suits or adapted clothing, which should not allow ticks to crawl. The shirt should have long sleeves, which are secured with an elastic band at the wrists. Tuck the shirt into the trousers, and the ends of the trousers into the socks and boots. The head and neck are covered with a scarf.
Preventive vaccinations against tick-borne encephalitis
Thank you for your attention Reflection Sources used in the presentation: O.V. Voltsit, M.E. Chernyakhovsky Encyclopedia “Nature of Russia” http://spidersworld.ru/ http://www.zoopicture.ru/tag/pauk/
Biology lesson on the topic "Arachnids class". 7th grade
Biology teacher: Kriulina I.V.
Goals:
Educational: To acquaint students with the diversity and lifestyle of arachnids, the structural features and vital functions that allowed them to become one of the first settlers of land, their significance in nature and human life.
Developmental: Contribute to the continued development of skills in working with tests for further preparation for the State Exam and OGE, working with reference signals
Educational: Teach respect for nature, showing that each organism has its place in the ecosystem, its significance in nature and human life, its unique story and uniqueness.
Equipment: Table “Crustaceans”, “Arachnids”, reference signals, cards, tests on sheets
Lesson progress
I. Test of knowledge
– Where does cancer live, what are the features of adaptation to its environment in its external structure, behavior, reproduction.
– What are the features of the internal structure?
– Digestive system. (The intestines of crustaceans usually have a chewing stomach and a “liver” that opens into the midgut.) Why and how can crustacean stomachs chew?
– Why do you come across crayfish with one claw smaller than the other? (The crayfish’s claw can come off during a fight with an enemy or during an unsuccessful moult. Then it grows back (regenerates), but turns out to be smaller in size).
– Respiratory, circulatory system. Why can crayfish taken out of water remain 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 kept moist, the crayfish do not die).
– Excretory, nervous systems.
- Reproduction.
– What is the importance of crustaceans in nature and human life?
Biological dictation (All students answer in a notebook, followed by verification)
1.Crayfish breathes through 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 herbivores (No).
6. Cancer always moves backwards (No).
7. Cancer is characterized by regeneration of claws (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 cancer’s eyes compensates for the immobility of its head (Yes).
11.Crayfish are the “orderlies” of water bodies (Yes).
12. Cancer uses its jaws to grab food and send it into the mouth (Yes).
13. The abdomen of cancer consists of 10 segments (No).
14. Claws are organs of defense, attack, and food capture (Yes).
15. Cancer’s blood is red (No).
16. Female crayfish lay eggs in winter (Yes).
17.Crayfish live up to 50 years (No).
II. Learning new material
– Let’s once again list 3 classes from the type of Arthropods that we study: Crustaceans; Arachnids; Insects.
What are the names of Arachnids? Latin? (Arachnida).
– Who knows why?
- The famous naturalist D'Orbigny once sported trousers made from the web of Brazilian spiders. He wore them for a long time, but they did not wear out. And Louis XIV, the king of France, the parliament of the city of Montpellier once presented stockings and gloves woven from the silky threads of French spiders as a gift.
“It is well established that spider webs stop bleeding. Just take it fresh and clean.
– What is the spider itself, the owner of the web?
– The goal of our lesson: to find out not only the structure of spiders using the example of a cross, but also to talk about what arthropods are included in the class Arachnids, what role they play in nature and human life. Topic entry: “Class Arachnids.”
The Arachnida class includes up to 62,000 species.
These are haymakers, ticks, spiders, scorpions, etc. All of them are terrestrial animals, except for the silverback spider. Many people weave webs.
– What is common to all arthropods? (Limbs, chitinous cover). The body consists of 2 sections - the cephalothorax and abdomen. The abdomen is separated from the cephalothorax by a constriction. They do not have antennae or compound eyes. There are 4 pairs of legs on the cephalothorax.
Also several pairs of simple eyes; and below the jaw are chelicerae. The spider grabs the victim with them. There is a channel with poison inside. There are short, hairy tentacles, or pedipalps (organs of touch).
Below on the abdomen are arachnoid warts that produce cobwebs. These are modified abdominal legs. (What does this mean?) - About ancestors who had legs for movement. On his hind legs there are comb-like claws that help pull out the arachnoid threads from the glands and collect them into one.
The thread consists of protein. From the arachnoid 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 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 a silkworm caterpillar.
But industrial production such threads cannot be established, because spiders are very voracious and you can’t get enough flies, and the climate is not suitable everywhere.
The spider weaves a trapping net 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, waiting for 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 heading towards a fly only if there is a fly there average size: if a small fly hits, the spider does not pay attention to it. How does a spider know the size of its prey?
The circulatory system is like that of crayfish. Which?
- Unclosed. Hemolymph. The heart has the shape of a tube or double rhombus
Respiratory system. The spider breathes atmospheric air. It has a pair of pulmonary sacs, entwined with blood vessels, and bundles of trachea, tubes that permeate the body of the animal.
Working with a textbook drawing (p. 123)
Excretory system. The 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. Like crayfish, only developed chest nodes and suprapharyngeal node.
Reproduction system. Dioecious animals. Fertilization in the female’s body. The female lays eggs openly or entwines them with a web (cocoon).
– There are 62,000 species of arachnids in nature.
We will get to know some of the representatives, as they live in our area and are very dangerous.
– Karakurt (its poison is 15 times stronger than that of a rattlesnake).
- Tarantula.
– Scorpio (found in Central Asia, the Caucasus, Crimea).
– Tarantula (its digestive juice dissolves 3 g of mouse tissue per day, weighing 20 g).
- Haymaker.
– Serebryanka (
– In addition to Spiders, Arachnids also include ticks (messages
– How are ticks and spiders similar?
– How are they different?
– Which mite reduces the yield of fruit and melon crops?
A – taiga, B – scabies, C – dog, D – spider.
– Which ticks are harmful to human health?
A – soil, B – scabies, C – canine, D – arachnoid.
Did you know that in ancient times kings and Popes and great scientists died from scabies: Herodotus, Philip II and Pope Clement VII.
– Are arachnids necessary in nature?
– Without spiders, people could die from various diseases, since 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 birds.
– Some harm plants, animals and humans.
– They are carriers of diseases.
– Participate in soil formation.
– And once spiders helped the French defeat Holland.
So, general signs arachnids:
Mostly, land species;
4 pairs of walking legs;
Predators => adapt, venom glands, spider warts;
Body length from 0.1 mm to 12 cm.
III. Consolidation of knowledge
Given syllables: PA SE NO KA RA SKOR UK KO SETS KURT PION
Make up the names of arachnids from them.
(spider, haymaker, karakurt, scorpion)
IV. Homework.
Subject: biology
Teacher: Talitskikh Marina Vladimirovna
Educational institution: MBOU - secondary school in the village of Veseloye, Mozdok district
Topic: "Arachnids"
Basic provisions on the topic:
1. - Class Arachnida.
- 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.
- On the cephalothorax there are six pairs of limbs - chelicerae, tentacles and four pairs of walking legs. There are no legs on the abdomen. Their respiratory organs are the lungs and trachea.
- Arachnids have simple eyes. Arachnids are dioecious animals.
- The body length of various representatives of this class is from 0.1 mm to 17 cm. They are widespread throughout the globe. Most of them are terrestrial animals. Among ticks and spiders there are secondary aquatic forms.
- The arachnid class includes up to 60 thousand species.
2. External structure and lifestyle of spiders- rice. 91 page 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, and on the window frames of suburban and village houses. Most of the time, the spider sits in the center of its trapping network of adhesive thread - cobweb.
- The spider's body 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 there are four pairs of eyes, and below there 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 victim’s body. Next to the chelicerae there are short organs of touch covered with sensitive hairs - the tentacles. Four pairs of walking legs are located on the sides of the cephalothorax.
- The body is covered with a light, durable and fairly elastic chitinous cuticle. Like crayfish, spiders periodically molt, shedding their chitinous cover. At this time they grow.
- 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, like in crustaceans, the body cavity is of a mixed nature - during development it arises from the connection of the primary and secondary body cavities.
3. Digestive system
- The cross spider cannot feed on solid food. Having caught prey, for example some insect, with the help of a web, he kills it with poison and lets it into his body digestive juices. After some time, the contents of the captured insect liquefy and the spider sucks it out. All that remains of the victim is a chitinous shell. This method of digestion is called extraintestinal.
- The spider's digestive system consists of the mouth, pharynx, esophagus, stomach, and intestines. In the midgut, long blind processes increase its volume and absorption surface. Undigested residues are expelled through the anus.
4. Respiratory system.
- The spider's respiratory organs are the lungs and trachea. The lungs or pulmonary sacs are located at the bottom of the abdomen, in the front part. These lungs developed from the gills of the distant ancestors of spiders that lived in water. The cross spider has two pairs of non-branching trachea - long tubes with special spiral chitinous thickenings inside. They are located in the back of the abdomen.
5. Circulatory system
- in spiders it is not closed.
Heart looks like a long tube located on the dorsal side of the abdomen. Blood vessels extend from the heart. Like crustaceans, spiders have hemolymph circulating in their bodies.
6. Excretory system
- represented by two long tubes - Malpighian vessels.
- One end of the Malpighian vessels ends blindly in the body of the spider, the other opens into posterior section intestines. Metabolic products are removed through the walls of the Malpighian vessels, which are then excreted. Water is absorbed in the intestines. That. Spiders save water, so they can live in dry places.
7. Nervous system
- the spider consists of the cephalothoracic ganglion and numerous nerves extending from it.
8. Reproduction.
- Fertilization in spiders is internal. The male transfers sperm to the female's genital opening using special outgrowths located on the front legs. After some time, the female lays eggs and braids them with a web. This is how a cocoon is formed.
- Small spiders develop from the eggs. In the fall, they release cobwebs, and on them, like parachutes, they are carried by the wind over long distances - resettlement occurs.
9. Variety of arachnids
Ë Spiders
Ë Haymakers
Ë Scorpios
Ë Pliers
