Which crustaceans are of commercial importance. Lesson summary "diversity of crustaceans and their significance." Shchitni - a peculiar group of crustaceans

What role do crustaceans play in human life you will learn from this article.

What are crustaceans?

Crustaceans are a diverse and numerous group of mainly arthropods that live in aquatic environments. These include about 40 thousand modern species crustaceans. Some of them are bottom-living, while others are an integral part of freshwater and marine plankton. These are, as a rule, mainly active crawling or swimming animals. But among such crustaceans you can also find motionless attached forms - such as sea acorns and ducks. Some of the crustaceans have adapted to life on earth. For example, woodlice can live in the soil of various latitudes, even in the desert, but at the same time they lead a rather hidden lifestyle and live in burrows

. What role do crustaceans play in human life?

  1. The importance of crustaceans in human life cannot be exaggerated - since freshwater and marine species Crustaceans are food for most species of fish and other animals. Daphnia and other crustaceans serve as food for various freshwater fish and their larvae.
  2. Some types of crustaceans are able to strain water with their thoracic limbs during feeding. As a result, water quality improves. They destroy the corpses of the dead by eating them and their excrement. This prevents the decomposition of organic matter in the water and its blooming.
  3. People use crabs or lobsters as food, fried or boiled. They have a beneficial effect on the body. Useful material, which are contained in crustaceans, improve vision and normalize the functioning of the nervous system. Their use reduces the risk of malignant tumors. Crustaceans are a source of vitamins, iron, calcium and zinc.
  4. Woodlice, which live on land, are able to process plant material, thereby enriching the soil and increasing its fertility.

We hope that from this article you learned what role crustaceans play in human life.

Municipal state educational institution Lizinovskaya secondary school

Development of an open lesson on the topic:

“The diversity of crustaceans, their significance in nature and human life”

Class – 7

Lesson developed by teacher

biology-chemistry

Kurochkina Tatyana Andreevna,

2014

Theme: “The diversity of crustaceans, their significance in nature and human life.”

Lesson type: combined

Target:

to form theoretical knowledge about the structural features and vital functions of crustaceans in connection with their habitat;

reveal the significance of crustaceans in nature and human life.

Tasks:

Educational

consider the structural features of arthropods using crustaceans as an example;

Will reveal character traits structure and vital processes of crustaceans;

To introduce the diversity of crustaceans and their significance in nature and human life;

Developmental

Develop logical thinking;

Ability to establish cause-and-effect relationships; ability to compare and generalize.

Independent work skills;

Develop communication skills students (communication skills).

Educational

Foster a work culture;

Ecological culture, culture careful attitude to nature.

Methods:

Verbal – mini-lecture (students’ messages, teacher’s explanation)

Visual – photographs, pictures, drawings from presentation work

Method of independent work in groups

Method of collective solution of creative problems

Equipment:

Microscope, micropreparations (daphnia, cyclops), “living drop” culture

Laptop, projector, presentation; task packages.

Main stages of the lesson

Stage name

Main content

time

1.Organizational moment

The teacher’s word, the psychological attitude of students for success

2 minutes

2. Survey on the material covered

Work in small groups with an individual task (package), results on the board for verification, grading of the group by the “leader”

(method of independent work in groups, method of solving creative tasks)

    min

3.Main material (new)

Student message (mini-lecture) with students writing in their notebooks on the issue"The diversity and significance of crustaceans." (Use of images of animals, examination of micropreparations with crustaceans)

general characteristics crustaceans

physical minute

    min

4. Fastening

Control of acquired knowledge - testing with verification using a key.

5 minutes

5. Homework assignment

analyze issues that caused difficulties for discussion in the next lesson

3 min

During the classes:

    Organizing time - welcome speech from the teacher

    knowledge updating survey

To repeat questions from the material covered, we will split into groups of 4-3 people and choose a leader who will be trusted to evaluate our knowledge.

Group 1 task – “general characteristics of arthropods” the result should be displayed on the board in the form of a crossword puzzle.

Questions for the crossword:

    symmetry of cancer body...

    Cancer has a body cavity...

    The body of animals is……..e.

    The body cover consists of...

Group 2 task – “external structure crayfish", the result is displayed on the board in the form of a table (filling out the table).

Cancer body parts

Structural features

Veils

chitin

Two, cephalothorax and abdomen

Number of walking legs

5 pairs

Number of abdominal legs

4-5 pairs

Group 3 task – “internal structure of a crayfish”, “revive the crayfish” card: fold in a certain order internal organs cancer.

Group 4 task – justify the correctness or incorrectness of expressions involving crayfish (“you will find out where crayfish spend the winter”; “wait for the crayfish to whistle on the mountain”; “the swan rushes into the clouds, the crayfish moves back, and the pike pulls into the water”).

When ready, students come to the board and show their results (! The results are discussed together).

The “leader” gives grades to the members of his group.

    Main material

You need to understand 3 questions: 1) crustaceans - a large group (about 30 thousand species), leading different image life. 2) the importance of crustaceans. 3) general characteristics of crustaceans.

Students make a message, and listeners make notes in their notebooks according to the following scheme:

Name crustacean-image life - meaning.

Example:

Daphnia is a free-living, freshwater form - food for fish.

Cyclops is a free-living, freshwater form and an intermediate host of the broad tapeworm.

Cancer is a water orderly.

Shrimp are food for humans.

Sea acorn - damage to the bottom of ships.

Working with a microscope (Daphnia, Cyclops - freshwater forms)

General characteristics - animals with mixed cavity, bilateral symmetry. Body parts: cephalothorax and abdomen. The body is segmented.The limbs are jointed and bibranched. Two pairs of antennae. Gills. Circulatory system open The nervous system is similar to that of annelids (peripharyngeal ring and ventral nerve cord). Organ for secreting steam from green glands.

There are about 20-30 thousand species in total.

Physical exercise in class

4. Fastening: testing will show how we have mastered the material - the “crustaceans” test

1. Crustaceans are...

b) terrestrial animals

a) daphnia, shrimp, woodlice

b) big pond snail

c) Cyclops

A) digest food

B) both answers are correct

B) move away from danger

A) breathe using gills

C) both answers are correct

9. As a result of gas exchange...

B) all answers are correct

14. The heart of arthropods...

A) two-chamber

B) tubular

B) three-chamber

Reply to test "crustaceans"

the work is completed more than 90% - “5”

80% - “4”

by 70% - “3”

Home task: those questions that caused difficulty in understanding at home, we will return to their discussion in the next lesson.

Thanks everyone for your work!

Lesson appendix

1. Consolidation of the material covered

Test "crustaceans"

To get a “5” you must answer at least 90% of the questions correctly, “4” - no less than 80% of the questions, “3” - no less than 70% of the questions.

1. Crustaceans are...

a) animals capable of flight

b) terrestrial animals

c) mostly aquatic animals

2. Representatives of crustaceans include...

a) daphnia, shrimp, woodlice

b) large pond snail

c) Cyclops

3. Cancer is characterized by molting, which is a process...

A) changes in the outer integument of an animal

B) moving backwards

B)removal of undigested food debris

4. Sense organs help crustaceans...

A) digest food

B) both answers are correct

B) move away from danger

5. Crustaceans are adapted to life in water, since...

A) breathe using gills

B) the abdomen ends with a caudal fin

C) both answers are correct

6. The defense organ of crayfish is...

a) eyes b) long antennae c) claws

7. In fresh water bodies, fish fry eat...

A) daphnia, cyclops b) woodlice c) shrimp

8. The organs for excreting cancer are...

A) green glands b) kidneys c) intestines

9. As a result of gas exchange...

A) is removed from the body carbon dioxide

B) the cancer body only receives atmospheric oxygen

B) oxygen comes from the environment and is released into environment carbon dioxide

10. The sense organs of crayfish include...

A) organs of vision, hearing, touch b) respiratory organs

B) all answers are correct

11. Arthropods originated from...

A) annelids b) flatworms c) roundworms

12. In crayfish, there are different types in the body...

A) three departments b) two departments c) four departments

13. High accuracy the movements of most arthropods are associated with...

A) with the advent of body segmentation

B) with the appearance of chitinous cover

B) with the appearance of muscle bundles

14. The heart of arthropods...

A) two-chamber

B) tubular

B) three-chamber

15. Of the listed crustaceans, the ones that live on land…

A) woodlice B) daphnia C) cyclops

Reply to test "crustaceans"

2. Tasks for questioning and updating knowledge on the topic “General characteristics of arthropods. Peculiarities of the structure and vital processes of crustaceans using the example of crayfish.”

Task No. 1.(creative tasks for collective solution)

There is an expression

1) “You will find out where crayfish spend the winter!”

Where do crayfish spend the winter?

2) “The swan rushes into the clouds, the crayfish moves back, and the pike pulls into the water.”

Is cancer moving backwards?

3) “Wait for the cancer to whistle on the mountain!”

Can cancer climb a mountain?

Can cancer whistle?

( When the cancer whistles on the mountain” - this is what they say, meaning: “it is unknown when”; "in an indefinite future tense", "never". The saying means the impossibility of doing something. The creators of this Russian proverb were sure that crayfish living on the river bottom would not leave their habitat, would not come to land, and certainly would not whistle. Do crustaceans whistle? Among crustaceans, there are about forty thousand different species and not all of them are strictly related to aquatic environment. Some are even capable of making sounds. Fiddler crabs (or fiddler crabs) live in the intertidal zone of tropical seas. They can stay on land for a long time. They have nothing to whistle with (they need lungs to whistle), and crabs, although they crawl onto land, breathe not with their lungs, but with their gills. But they learned to communicate using sound. Hitting the ground with their claws, they knock, thereby notifying their fellows of approaching danger. Click crayfish live in shallow sea waters. They can make clicking sounds with their claws. But it's not just a knock. When a crayfish hits a “moving” finger of its claw against a stationary one, an effect called cavitation occurs: a sharp drop in pressure in the liquid causes gas bubbles to form, which is accompanied by an explosive sound. Many species of lobsters (these are large sea crayfish without claws) are capable of producing crackling and grinding noises. But they produce sounds differently - as if they were playing a string instrument. On the antennae of lobsters, at the very base, there is a comb used as a bow, which the crayfish moves with great frequency across the outgrowth on the head - the “file”. The pitch and volume of the sound can vary depending on how hard you press the bow. It is not known exactly who all this “music” is intended for. Most likely, lobsters scare away predators in this way, because most often they make sounds at the moment of fright. It has not been proven, but it is not excluded that this is how they communicate with their relatives.At the time of the appearance of the saying about whistling cancer the last word written with a capital letter. Cancer is the nickname of the famous Odessa marviher (as touring thieves were once called) Rakachinsky, given to him not so much because of his surname as because of a special feature - his strongly bulging eyes. Once Cancer lost a bet, according to which he was obliged to whistle three times on a bypass road (Škodova Gora) during its intensive use. Since rains flooded Peresyp extremely rarely, this circumstance gave rise to the famous phrase).
Answer the questions posed after the group discussion.

Task No. 2 (“General characteristics of arthropods”)

Give answers to the questions asked. Write the answer in the form of a crossword puzzle according to the diagram (on the board). Answers (words) can also be in adjective form; there can be several answers to one question

Questions for the crossword:

    A fly, a crayfish, a spider belong to the type…. (keyword write from top to bottom)

    symmetry of cancer body...

    Cancer has a body cavity...

    name of classes of the type being studied...

    animals of this type originated from ..... worms.

    The body of animals is……..e.

    limbs of this type..., hence the name of the type itself.

    The body cover consists of...

Task No. 3 " Internal structure crayfish" Card "revive the crayfish"

Collect the organs and organ systems of crayfish in the correct order and the crayfish will “come to life”!

Organs in the form of separate parts.

Task No. 4 “External structure of crayfish” draw up a table prepared in advance on the board

Cancer body parts

Structural features

Meaning(optional question)

Veils

chitin

Body parts (number and name)

Two, cephalothorax and abdomen

Eyes (number of simple or complex, location)

1 pair of complex ones, on the front of the cephalothorax

Antennae (number and location)

2 pairs, short (olfaction), long (touch), on the cephalothorax

Number of walking legs

5 pairs

Number of abdominal legs

4-5 pairs

Draw a conclusion about the adaptability of crayfish to its habitat.

Physical exercise in class

    To warm up the cervical vertebrae “Turtle” - without lifting the body from the chair, “press” the shoulder girdle towards the floor, and try to reach the ceiling with your head (movement of the turtle’s head).

    Exercise for development correct posture(used in mandatory cadets of the Kremlin troops) - “throw your jacket on the floor”, i.e. we must imagine that our shoulder girdle is a jacket and it must be thrown off in one movement to the floor.

    Exercise for hands - drawing a figure eight in the air with one hand, then with the other, and then simultaneously, with both hands, drawing a figure eight in the air.

Additional material

The meaning of crustaceans

    Daphnia, Cyclops and other small crustaceans consume a large number of organic remains of dead small animals, bacteria and algae, thereby purifying the water. In turn, they represent an important source of food for larger invertebrate animals and juvenile fish, as well as for some valuable planktivorous fish (for example, whitefish). In ponds fish farms and in fish hatcheries, crustaceans are specially bred in large pools, where favorable conditions are created for their continuous reproduction. Daphnia and other crustaceans are fed to juvenile sturgeon, stellate sturgeon and other fish.

    Many crustaceans have commercial value. About 70% of the world's crustacean fishery consists of shrimp, and they are also bred in ponds created in the coastal lowlands and connected to the sea by a canal. Shrimp in ponds are fed with rice bran. There is a fishery for krill - planktonic marine crustaceans that form large aggregations and serve as food for whales, pinnipeds and fish. Food pastes, fat, feed meal. The fishing for lobsters and crabs is of less importance. In our country in the waters of the Bering, Okhotsk and Japanese seas Kamchatka crab is harvested. Commercial fishing for crayfish is carried out in fresh water bodies, mainly in Ukraine.

Bionics and crustaceans

Chitin - construction material insects and crustaceans

Insects, spiders and crayfish create their shells from chitin. This natural substance may also be useful for humans. Lots of features. Chitin is a multifunctional material that can be used for various purposes by modifying it accordingly. The framework of chitin molecules, for example, may contain other substances that make chitin harder. This is exactly what can be observed in the stings of bees and wasps, which, without bending or breaking, must penetrate into tissues, or in the thin but hard parts of the joints of the wings of flies and bees, which can withstand heavy loads. Used in other sequences, chitin can be very soft. This is used, for example, by arthropods - in the articular skin between the plates or tubes of the chitin shell. Only thanks to this, the plates can move, while harmful substances do not penetrate into the insect’s body between the individual plates. And finally, calcareous material can be mixed into the chitin, thereby imparting rigidity to the shell. Crustaceans use this opportunity to protect themselves from enemies. Material of the future. Chitin is a growing material. It can be obtained, among other things, from crab shells north sea and then refined using various chemical processes. Chitin could be an important material of the future, with many applications. Especially great importance this material is used in medicine and pharmaceuticals, since human body does not perceive chitin as foreign body and therefore does not reject him. By applying chitin, for example, the treatment of burns can be significantly improved.

Objectives: - ensure the assimilation of knowledge about the basics of their classification (main classes of type), features of adaptation to the environment; - continue to develop the skills to observe, recognize arthropods in nature, in tables, drawings, in collections, and compare them with each other; - develop skills in working with textbooks and additional literature.


Type Arthropods Subtype Gill-breathing Class Crustaceans (Primary aquatic arthropods) Subclass Lower crustaceans Subclass Higher crustaceans Order Branchiopods (branchopods) Order Stomatopods (crayfish - mantises) Order Phytopods (shields) Order Isopods (woodlouse, water burro) Order Cladocera (daphnia) Order Unpods (amphipods) Order Copepods (cyclops) Order Euphausiae Order Caproeds (carpoeds) Order Decapods ( crayfish, lobster, shrimp, crab) Order Barnacles (sea acorns, sea duck) Order Shelly crustaceans.









Lower crustaceans Order phyllopods Shchitni have 70 pairs of legs. Biologists consider shields to be living fossils (relics), since their appearance has remained virtually unchanged for 200 million years. Moreover, the average “lifetime” of an individual species is no more than several million years. Swimming organs - pectoral legs


Lower crayfish Order Cladocera Daphnia " water flea» Swimming organs - the second branched pair of antennae In ponds and puddles middle zone In Russia, the following crustaceans of the genus Daphnia are often found (and most popular among aquarists): Daphnia magna (D.magna), female up to 6 mm, male up to 2 mm, newborns 0.7 mm. They ripen within 24 hours. Litters every other day. There are up to 80 eggs in a clutch (usually 20-30). Life expectancy is up to 3 months. Daphnia pullex (D.pulex), female up to 3-4 mm, male 1-2 mm. Litters in 3-5 days. There are up to 25 eggs in a clutch (usually 10-12). They live for days.


Lower crayfish Order Copepods Cyclops Swimming organs - the first unbranched pair of antennae Different types of Cyclops can be from 0.6 to 5.5 mm in length. In females, the egg sacs are located on the abdomen. They live among the plants of the coastal strip of standing reservoirs. They feed on plankton. Development goes through several larval stages. playing important role in fish nutrition.




Sea acorns (balanuses) Lower crayfish Order Cirripedes Shell-house diameter different types 1-11 cm. The house is formed by calcareous plates surrounding the body of the crustacean. Motionlessly sessile (on a hard substrate) marine animals. Filter food particles from the water using the pectorals. Hermaphrodites. The main culprits of fouling on the bottoms and sides of sea vessels.


Sea ducks, also known as sea truffles. They look like shellfish. But in fact, these are crayfish, and the tentacles are their legs. With the help of legs extended from a shell that resembles a shell, the sea duck sticks to the rocks. Or to the bottoms of ships. In a particular case, ducks settled on a sunken pillar. Which for some reason floated up and washed up on the coast of Wales. Monsters that are so scary in appearance are actually a delicacy. They are eaten with pleasure in Portugal and Spain. Where they catch it on purpose. And they sell for $300 per kilogram. Sea ducks have juicy pinkish-white meat. Steamed, they taste like both an oyster and a lobster. These crayfish can also be eaten raw, whoever does not disdain them. Lower crayfish. Order barnacles. Sea duck.


Lower crayfish Order Shelly crayfish Modern representatives of this order are small: no more than 1-2 mm, a few up to 6 mm. All inhabitants of water, some fresh, some sea. They feed primarily on animal matter, especially the carcasses of aquatic animals. Their significance for humans is the same as that of other lower crustaceans, that is, they serve as food for fish.


Mantis crab Higher crustaceans Order Stomatopods Named for some similarity with insect mantises. mantises Length up to 20 cm. Lives in the Mediterranean Sea. Lives at the bottom in burrows. Predator; grabs prey (crustaceans, mollusks) with its highly developed second pair of thoracic legs. It has commercial significance.


Higher crayfish Order of isopods. Water burro (similar to land woodlouse) woodlice Typically 1 - 1.2 cm in length. Found in stagnant or slowly flowing freshwater bodies, as well as in brackish waters; among plants or at the bottom of reservoirs. Feeds on dead plants (detritivores). Up to 1.8 cm in length. Found on land in damp places. It feeds on dead leaves and rotting wood - a detritivore. Plays an important role as a destroyer of dead organic matter and in soil formation.


Amphipod Higher crayfish Order Multipeds About 1.3 – 1.7 cm in length. Amphipods include benthic and planktonic life forms. Quite demanding in terms of oxygen and lime content. It feeds mainly on plants, as well as carrion. Amphipods are filter feeders and use antennae. During its almost 10-month life, it bears offspring 6-9 times. The main food of fish. “Lying on its side”, they glide at the bottom of the reservoir using the last pair of pectoral and first three abdominal legs for swimming.


Whales feed on small crustaceans - krill. The composition of krill includes euphausian crustaceans measuring 10-65 mm. A specimen can reach a length of 6 cm and a weight of 2 g, cmg life expectancy is up to 6 years. Life-flight Feeds Antarctic krill feeds on plankton. plankton At the same time, krill itself is food for fish , penguins and penguins and other species of marine fauna. fauna Higher crayfish Order Euphausiaceae




Kamchatka "crab". One of the largest Far Eastern crabs, it is a commercial object. Not a true crab, but belongs to the hermit crab family, related to hermit crabs. The main difference from real crabs is the fifth pair of walking legs hidden under the carapace, that is, not 4, but 3 pairs of limbs are used for movement. carapace It inhabits the Sea of ​​Japan, Okhotsk and Bering Sea. The male carapace is on average 16 cm wide, and in the Gulf of Alaska 28 cm. The distance between the ends of the average walking legs of large individuals is 1.5 m, and total weight body up to 7 kg. GIANT CANCER










A 140-year-old, 20-pound giant lobster named George left the aquarium of a posh seafood restaurant on Park Avenue in Manhattan at the request of the animal rights group People for the Ethical Treatment of Animals (PETA). GIANT CANCER


Lobster Some decapods live long: American lobster up to 50 years, broad-toed crayfish up to 20 years, king crab up to 23 years, spiny lobster over 15 years, mitten crab up to 6, sometimes up to 10 years, palm thief more than 10 cm long are at least 5 years old, shrimp usually do not exceed 4 years, and small species do not live up to a year. Higher crustaceans Order decapods


GIANT CRAWLISH Lobsters are common in warm seas. Body length up to 60 cm. Similar to lobsters, but lacking claws. Lobsters body and thick antennae are equipped with powerful spines. In the first year of life, it molts about ten times. The new shell hardens with spikes within 2-3 weeks. Lobster meat is considered a delicacy.delicacy





Crayfish are an inhabitant of clean water bodies. Usually about 12 – 16 cm in length. Coloring is variable. The lifestyle is crepuscular: in shelters during the day, crawling along the bottom at night in search of food - small animals, plants and carrion. In case of danger, it makes sharp strokes with its belly and quickly swims away with its rear end forward. Mating in autumn. The female takes care of the offspring by attaching fertilized eggs to her abdominal legs. The larvae hatch in May of the following year and quickly develop into crustaceans about 1 cm in length.



What fable is simply unthinkable without it? Why, despite the insignificant size of the Calanus crustaceans, do huge whales feast on them? In the stomach blue whale up to 1.5 tons of planktonic “porridge” can be placed. One clutch of a female daphnia contains approximately 60 eggs. After 15–20 days, young daphnia hatch, which are soon able to lay eggs themselves. How many daphnia can approximately appear from one young female in three summer months? It crawls backwards, backwards, everything is under water, it grabs with its claw. There is a huge crayfish in the sea. Guess what it's called? He lives at the bottom of the sea. Moves forward sideways. The claws cut like a knife, similar to a large spider. Looks like a big spider. What animal wears a tailcoat? Cancer - tailcoat Who looks at cancer through a telescope? Constellation Cancer - astronomer Emblem on the uniform cap of sailors Good luck!!! plankton

What is the importance of crayfish in nature and human life you will learn from this article.

What are crustaceans?

Crustaceans are a diverse and numerous group of primarily arthropods that live in aquatic environments. These include about 40,000 modern species of crustaceans. Some of them are bottom-living, while others are an integral part of freshwater and marine plankton. These are, as a rule, mainly active crawling or swimming animals. But among such crustaceans you can also find immobile attached forms - such as sea acorns and ducks. Some of the crustaceans have adapted to life on earth. For example, woodlice can live in the soil of various latitudes, even in the desert, but at the same time they lead a rather hidden lifestyle and live in burrows

The importance of crustaceans in nature and human life

The importance of crustaceans in human life cannot be exaggerated - freshwater and marine species of crustaceans provide food for most species of fish and other animals. Daphnia and other crustaceans serve as food for various freshwater fish and their larvae.

Some types of crustaceans are able to strain water with their thoracic limbs during feeding. As a result, water quality improves. They eat dead organisms and this prevents the decomposition of organic matter in the water and its blooming.

People use crabs or lobsters as food, fried or boiled. They have a beneficial effect on the body. The beneficial substances contained in crustaceans improve vision and normalize the functioning of the nervous system. Their use reduces the risk of malignant tumors. Crustaceans are a source of vitamins, iron, calcium and zinc.

Woodlice, living on land, are capable of processing plant material, thereby enriching the soil and increasing its fertility.

We hope that from this article you learned what role crustaceans play in human life.

Subject: Diversity of Crustaceans, their role in nature and human life.

Target: consider the diversity of crustaceans, their role in nature and human life.
Exercise:
Get acquainted with various types crustaceans, their structural features, habitat.
Consider the classification of crustaceans..
Determine the importance of crustaceans in nature and human life.
Have a creative and interesting time

Basic concepts: orders Decapods, Isopods, Cladocera, Copepods, Leafpods, Carpoeds.
Equipment and materials: posters with images of crustaceans, handouts for student work, a biology textbook for grade 8, diagrams, drawings, tables, multimedia board, videos, presentation
Form of organization educational activities : cool lesson.
Lesson type: mastering new knowledge.
During the classes

I .Organizing time . Greetings to the participants. Announcing the topic and purpose of the lesson. Good day everyone! I'm glad to see everyone in our lesson
II Updating the basic knowledge and skills of students.

1) Brainstorming method
1. What parts does the cancer body have? (cephalothorax and abdomen).
2. How many pairs of walking legs does a crayfish have? (five)
3. What shape is the cancer heart? (Shapes of a five-pointed pouch)
4. In what part of the cancer body are the excretory ducts located?
glands? (On the head)
5. How do crayfish reproduce? (Calf throwing)
6. Where do crayfish spend the winter? (In the hole)
7. How long do crayfish live? (20-30 years)
8. How many times a year does a crayfish molt? (1-2 times)
9. Respiratory organs of cancer. (Gills)
10. Olfactory organs of cancer. (Long mustache)
11. Cancer circulatory system. (Unclosed)
12. Digestive system cancer. (Food is digested in the stomach, which consists of two sections)

2) Make a logical chain “Digestive system of crayfish”

Oral opening→ pharynxesophagusstomach → intestinesanal hole

III . Motivation of educational and cognitive activities of students

... Such a number of legs, such means of transportation - and all this in order to move backwards! F.Krivin

People say he backs away like a cancer. How can this be explained? The peculiar appearance of our new acquaintance, the crayfish, has led to the well-known misunderstanding about where his eyes are and why, when moving, he does not crawl forward, but backs away. This misunderstanding contributed to the emergence of an original legend about why cancer’s eyes were in the wrong place.

Cancer kept asking God to give him such huge eyes as those of an ox. The Lord gave him small eyes. “They can only be attached from behind,” said the offended cancer. The Lord left the crayfish with small eyes, but made it move forward with its tail, and it turned out as if the crayfish had eyes behind it.

Problematic issues: Do you think cancer has relatives? Are they similar to the crayfish we know? Where can you find them? What they are and who they are, today we will find out in class. So, the topic of our lesson...
Slide 1
Topic: Diversity of crustaceans, their role in nature and human life.
Purpose: to consider the diversity of crustaceans, their role in nature and human life.

Slide 2,3,4
Assignment: Get acquainted with various types of crustaceans, their structural features, and habitat. Consider the classification of crustaceans. Determine the importance of crustaceans in nature and human life. Have a creative and interesting time.

IV. Students' perception and assimilation of new material.
Slide No. 5,6,7

There are more than 50 thousand crustaceans in the world, which can be found where you wouldn’t even expect them. So, we are going on a virtual journey into the world of crustaceans. The class was divided into four groups in advance. Consultants were selected from each group. Each group received a task. Prepare a presentation. Determine the structural features and vital functions of representatives of a certain order. Their importance in ecosystems. 4 groups: 1) detachment Decapods; 2) order Cladocera; 3) orders Phytopods, Copepods; 4) orders Isopods, Carpoeds
Today we, a group of researchers, decided to find out everything about the representatives of the class Crustaceans: how many there are, where they live and what they are. To do this, we will take a short trip, during which we will study representatives of crustaceans.

Slides No. 8-12Order Decapods.
The most famous order is Decapods. Body (length 0.3-80cm) various shapes, divided into a cephalothorax and abdomen, on the head there are 2 pairs of antennae and eyes, and have 5 pairs of walking legs. Several species of hermit crabs live in the Black Sea. Young crustaceans that have just hatched from eggs find gastropods with shells of appropriate sizes, kill and eat the host, and hide their abdomen in an empty shell.
Now look at this amazing specimen - the invisible crab. Invisible - because it is almost impossible to see it among the algae. This lean, long-legged crab is a master of camouflage. He carefully places small bushes of algae on his shell. So it wanders unnoticed in its “camouflage.” Shrimp, widespread in all seas and oceans, are found in some fresh water bodies. The greatest species diversity is in tropical seas. Found in the Black and Azov Seas.
Paleontologists have discovered the fossilized remains of a shrimp that lived on the planet about 360 million years ago. Thus, this find became the oldest among the fossil species of decapods.

Slidey No. 13-14Order Cladocera
A group of ancient and primitive crustaceans, there are about 1,500 species. The body (length 0.1-10 mm) is divided into a head and a trunk, partially or completely, covered with a bicuspid chitinous shield. The antenules are small, the antennae (antennae) are well developed, bibranched with setae, and are used for swimming. Distributed mainly in fresh water bodies. Representatives of this series are daphnia. Their sizes are very small: the body (1-3mm) of daphnia is enclosed in a translucent bivalve shell. Daphnia swim with the help of a second pair of antennae, jumping (for this they are also called “water fleas”). On their head there are two complex and one simple eye. Filtration feeding. Daphnia play an important role in the biocenoses of fresh water bodies, because they are the main food base of many
aquatic organisms, this is food for aquarium fish, this is an object of study.

Slide No. 15 Order Phytopods The body of these large crayfish (up to 5 cm long) is covered with a large shield.
Shrews usually live in small temporary bodies of water, swimming almost all the time with their ventral side down. However, a lack of oxygen can cause them to float on their backs near the surface of the water, since scale insects breathe using gills on their legs. They are omnivores. They consume not only plankton, but also large prey, including worms, midge larvae, and even weak tadpoles.
Shchitni live in temporary reservoirs. When ponds dry up during certain times of the year, in the absence of rain, the adults die during this drought and the eggs remain dormant (up to 9 years) until rains refill the ponds, allowing them to hatch. Dried shield eggs are easily dispersed by the wind, which ensures the spread of the species.

Slide No. 19-21
Importance in crustacean ecosystems
Almost all fish, both marine and freshwater, rely heavily on crustaceans for their existence. For the giants of the sea - toothless whales - crustaceans serve as the main food.
Crustaceans play a very important role in the economy of nature. Organic substances in water bodies are created mainly due to the activity of microscopic algae. Crustaceans eat these algae and are, in turn, eaten by fish. . On the other hand, they use huge masses of dead aquatic animals for food, thus ensuring the purification of the reservoir.
Many crustaceans are directly used by humans as valuable food products. In many countries, fishing for shrimp, crabs, lobsters, lobsters and others is developed. edible species. IN Lately Successful experiments are being carried out using marine planktonic crustaceans to obtain vitamins, fats and other important substances. Some types of crustaceans necessary for feeding young fish are bred at fishing factories.

Slide No. 24-28.

This is interesting!
The largest of all crustaceans (but not the heaviest in weight) is considered the “giant sea ​​spider", which is called the "stilt crab". It is found in deep-sea areas on the south-eastern coast of Japan. Adults of this species usually measure 254mm by 305mm, and their claws range in size from 2.43 to 2.74m.

Enough interesting event happened in Australia: the world's largest crab, weighing 6.8 kg, was caught off the coast of this continent. The width of this single this moment, the specimen reaches 38 cm.
Unusual in appearance, but at the same time, a beautiful crustacean monster due to its huge size got the name Tasmanian king crab And immediately there were societies that wanted to get this specimen of the crab - the British Sea Life Aquarium in the city of Weymouth bought it for $ 5,000, and now the most big crab in the world is a valuable exhibit in an aquarium.
The largest among lobsters and the heaviest among crustaceans is the American lobster (Homarus amerikanus). On February 11, 1977, a lobster weighing 20.14 kg and 1.06 m long was caught in the New Stockade area, Canada. The lobster was later sold to a restaurant owner in New York.
A British expedition discovered in the waters Pacific Ocean, off the coast of New Zealand, the largest shrimp in the world.
The length of this largest representative of crustaceans in its type was as much as 28 centimeters, while ordinary shrimp do not reach a length of more than 2-3 centimeters.

The smallest crustacean is the water flea (from the genus Alonella), measuring less than 0.25 mm in length. She lives in UK waters.
The smallest known lobster is Homarus capensis, living in southern Africa. Its total length is only 10-12cm.
the smallest crabs in the world - the so-called "pea crabs". Selected species These crabs have a shell size of 6.3 mm.
The longest-living crustacean is the American lobster (Homarus amerukanus). Largest representatives This species lives up to 50 years.

Slides No. 29-31
Folk wisdom

Whom does grief paint?
Not a blacksmith, but with tongs.
To avoid getting into trouble, he holds scissors in water.
Who has a mustache longer than his legs?
Not an egg, but in a shell, not a cat, but a mustachioed one.
Sitting aground, wiggling his mustache,

And he will go for a walk - backwards.

Crawling backwards, backwards

Everything under water is enough for claws
Proverbs and sayings

Only the crayfish move back.
Grief paints one cancer.
Cancer is especially scary because it is behind the eye.
It’s a miracle, not crayfish: they climb into the bag themselves.
Then it will be like a crayfish whistling in a pond.
Without fish and cancer, fish.
I went to the bottom to catch crayfish.
It doesn't matter what pot it is cooked in.
God had mercy on the cancer and gave him eyes in the back.
The cancer took pity on the frog and tore out its eyes.

While members of one team report on a particular order of crustaceans, others write down in a table all the species they hear or see.

Why are representatives of the class Crustaceans combined into one class?
2. Game "Field of Miracles"
This copepod received its name in honor of the mythical one-eyed giant.
What is it called?

(Cyclops)
On the desk:
3.Find the “extra” animal among those named:
crayfish, crab, daphnia, lobster, shrimp, lobsters.
4.Decipher which crustaceans are hiding behind the mixed up letters:
tsykrimo; winds; Tiguslan
(Woodlice) (shrimp) (lobster)

5. “Find out the name”, take a set of letters and make an anagram in a group, others guess

POIDROKO
MORA
TYGUSLAN
NIIDAF
KBAR
KRIMOTSY
WINDCREEKS
TISHCHIN

7. The basis of the integument of arthropods is organic matter
a) chitin; b) murein; c) starch; d) cellulose.

8. Body cavity of arthropods:
a) mixed; b) parenchyma; c) secondary; d) primary.

9. Nervous system of arthropods:
a) nodal; b) diffuse; c) stem; d) looks like a tube.

10. Excretory organs of crustaceans:
a) kidneys b) metanephridia; c) green glands; d) Malpilgian vessels.

11. Respiratory organs of crustaceans:
a) gills; b) trachea; c) pulmonary sacs; d) gills and lung sacs.

12. Note the number of pairs of limbs located on the head of the crayfish:
a) three; b) five; at seven o'clock; d) nine.

VII. Lesson summary.
- What are your impressions of the lesson?
- What did you like most?
- What interesting things did you learn?
- What methods would you like to use in the next lesson?
VIII. Student assessment.
At the beginning of the lesson, students are given tokens for each group; With correct answers, the commander gives tokens to a specific student.
At the end of the lesson, grades are given based on the number of tokens the students received.

IX. Homework .
Work through paragraph 20
Write a miniature essay on the topic “The fate of crustaceans in the future”



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