Slide 4

In the class of cephalopods, the most highly organized mollusks, there are about 650 species ranging in size from 1 cm to 5 m. They live in the seas and oceans, both in the water column and on the bottom. This group of mollusks includes octopuses, squids and cuttlefish.

These mollusks are called cephalopods because their legs have turned into tentacles, arranged like a corolla on the head around the mouth opening.

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External structure of a cephalopod

The body of cephalopods is bilaterally symmetrical.

It is usually divided by an interception into a body and a large head, and the leg is modified into a funnel located on the ventral side - a muscular conical tube and long muscular tentacles located around the mouth.

Octopuses have eight tentacles, cuttlefish and squids have ten. The inner side of the tentacles is lined with numerous large disc-shaped suckers.

The body is covered on all sides with a mantle.

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Movement of cephalopods

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Having overtaken the prey, the squid grabs it with its long hunting tentacles, holds it near its mouth with the remaining tentacles and bites off a piece with its sharp horny jaws. Then the food is ground in the throat using a special grater - a radula. The squid cannot swallow the prey whole or even in pieces due to its narrow esophagus.

The beak of the giant squid reaches a length of 15 cm.

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The giant squid architeitis is a genus of oceanic squid. It is the largest mollusk in the world. What are the sizes of architeitis? If with tentacles, then the record is 17.4 m. A squid of this size was thrown ashore in 1887 in New Zealand. The one found in 1878 on the coast of Newfoundland turned out to be slightly smaller: 16.8 m with tentacles, including 6.1 m for the body with head and 10.7 m for the tentacles.

Slide 9

In most cephalopods, the shell is greatly reduced and hidden in the body of the animal.

In cuttlefish, the shell looks like a calcareous plate lying under the integument on the dorsal side of the body. The squid has a small “feather” left from its shell, while the octopuses have no shell at all. The disappearance of the shell is associated with the high speed of movement of these animals. Cephalopods have a special internal skeleton formed by cartilage: the brain is protected by a cartilaginous skull, supporting cartilages are present at the base of the tentacles and fins.

Slide 10

Suckers on the tentacles of an octopus

Octopus. The octopus has invented a sophisticated method of hunting its prey: it covers it with tentacles and sucks on hundreds of suction cups, entire rows of which are located on the tentacles. The suction cups also help it move on slippery surfaces without sliding down. On the octopus' tentacle, suckers arranged in dense rows are clearly visible.

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The best defense against enemies is attack or camouflage?

Cephalopods do not give up without a fight: they are well armed. Their tentacles are lined with hundreds of suckers, and many squids also have claws, sharp and curved, like those of cats. There are no teeth, but there is a beak. Horny, hooked, it easily bites through fish skin and crab shells, and pierces through even the durable shells of bivalve mollusks.

In the process of evolution, cephalopods acquired an even more amazing miracle weapon - an ink bomb. Instead of a piece of living flesh, the squid throws out a crude fake of its own person in front of its open mouth to devour it. The squid seems to split into two before our eyes and leaves its disembodied double to the enemy, and quickly disappears.

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A copycat octopus disguises itself as a poisonous fish, repeating the contours and coloring of its body and even its method of movement - swimming parallel to the bottom

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Internal structure of a cephalopod

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Internal structure of an octopus

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Internal structure of an octopus

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Sense organs

The sense organs are well developed.

In terms of structural complexity and visual acuity, the eyes of cephalopods are not inferior to the eyes of many vertebrates.

Among cephalopods there are especially large-eyed ones. The diameter of the giant squid's eye reaches 40 cm.

Cephalopods have organs:

• chemical feeling
• equilibrium
• tactile signals are scattered in the skin
• photosensitive
• taste cells.

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Reproduction of cephalopods

Cephalopods are dioecious animals. During reproduction, male cephalopods use one of their hands to remove sperm packaged in “packages” from the mantle cavity and transfer it to the spermatheca of the female. The sizes of spermatophores range from 3 mm to 115 cm.

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Caring for offspring

Mother octopuses do not leave the eggs they lay for a moment. Gently wash them with a stream of fresh water. They drive away anyone who encroaches on them. And so - from 1 to 4 months without food.

Slide 19

General characteristics of cephalopods:

1. no sink
2. body divided into: head, tentacles, funnel
3. respiratory organs - gills
4. 3-chambered heart
5. well developed sense organs
6. complex nervous system

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The meaning of cephalopods

Slide 21

The importance of cephalopods for humans

Squid is not only canned, but also dried, fried, and boiled. Even in ancient Rome, skillfully prepared octopus was a common food. Recently, human “gastronomic” interest in cephalopods has increased sharply, since their meat is a complete protein food that can replace fish. Squid can be found in the sea in schools of thousands and are easily caught with nets. Octopuses are caught individually - with spears or using “jug traps”. In some countries, paint and ink are made from the ink liquid of cephalopods.

In addition, cephalopods are used as laboratory animals.

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The importance of cephalopods in nature

1. regulate the number of fish and crustaceans
2. are food for marine animals, especially cetaceans.

Cephalopods are connected with all the inhabitants of the ocean by invisible but strong threads of biological relationships. They eat many fish and crabs and themselves provide food for millions of predators that devour them: here are fish - sharks, moray eels, tuna, mackerel, cod; there are also birds - albatrosses, skuas, penguins and sea animals - whales, dolphins, seals.

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Origin of cephalopods

For four hundred million years, ammonites and nautiluses swam serenely on the waves. Then suddenly they died out. This happened eighty million years ago, at the end of the Mesozoic era. Science has not established with certainty when and how belemnites, the closest relatives of squid and cuttlefish, originated from nautiluses. Two hundred million years ago they already roamed the seas

Slide 24

Squids originated from belemnites. The kingdom of dinosaurs had not yet reached its greatness, and squids already lived in the sea. Octopuses appeared later - a hundred million years ago, at the end of the Cretaceous period. Well, cuttlefish are very young (in the evolutionary sense) creatures. They began their development at the same time as horses and elephants - just some fifty million years ago.

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Cephalopods

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Presentation on the topic "Cephalopods" by Lisa Filyutkina 7"a"

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Unique cephalopods Class Cephalopods are the most unusual, largest and most highly organized of mollusks. A number of unique features - great activity, method and speed of movement, an unusually highly developed nervous system, the beginnings of "intelligence", a set of means of defense and attack - puts cephalopods above all other groups of invertebrates and allows them to compete with vertebrates.

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Movement of a cephalopod In squids, cuttlefish, and octopuses, the mantle cavity functions like a jet engine. Through the mantle gap, water is drawn into the mantle cavity, and then, when it contracts, it is forcefully thrown out through the funnel, the body of the mollusk moves in the opposite direction.

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Exclusively marine Cephalopods are exclusively marine animals. They play a very important role in ocean life. Being predators, they eat a huge number of crustaceans, fish and other organisms and, in turn, themselves serve as food for many marine vertebrates - fish, birds, pinnipeds and whales. The most important enemy of cephalopods is the giant toothed whale - the sperm whale.

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External structure The body of cephalopods is bilaterally symmetrical. It is usually divided by an interception into a trunk and a large head, and the leg is modified into a funnel located on the ventral side - a muscular conical tube and long muscular tentacles located around the mouth. Octopuses have eight tentacles, cuttlefish and squids have ten. The inner side of the tentacles is lined with numerous large disc-shaped suckers. The body is covered on all sides with a mantle.

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The best defense against enemies is attack or camouflage? . Cephalopods do not give up without a fight: they are well armed. Their tentacles are lined with hundreds of suckers, and many squids also have claws, sharp and curved, like those of cats. There are no teeth, but there is a beak. Horny, hooked, it easily bites through fish skin and crab shells, and pierces through even the durable shells of bivalve mollusks. A cuttlefish can crush with its beak the shell of a large crayfish or the skull of a fish twice its size. In the process of evolution, cephalopods acquired an even more amazing miracle weapon - an ink bomb. The squid seems to split into two before our eyes and leaves its disembodied double to the enemy, and quickly disappears.

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Circulatory system A highly developed circulatory system allows cephalopods to reach gigantic sizes. Only in the presence of a capillary system is the existence of very large animals possible, since only in this case is a complete supply of oxygen and nutrients to the massive organs of giants ensured. The blood of cephalopods is blue due to the presence of the respiratory pigment hemocyanin, which contains copper. Hemocyanin is produced in special gill glands. The excretory organs are the kidney sacs, the appendages of the gill hearts, and the gills themselves. The main metabolic product of cephalopods - ammonia (more precisely, ammonium ions) - in many squids is not completely released, but partially accumulates in the body of the mollusks, providing them with neutral buoyancy.

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Digestive system The eaten pieces of food then enter the muscular stomach, which receives digestive juices produced by the liver and pancreas. The activity of the enzymes of these glands is very high, and within 4 hours the food is digested. Absorption occurs in the blind process of the stomach - the caecum, as well as in the liver. Undigested food remains enter the intestine and are thrown out. The liver is a large, oval, brownish organ usually located in front of the stomach. It performs several functions - it produces digestive enzymes, amino acids are absorbed in it, and it is also a repository of reserve nutrients. On the ventral side of the visceral mass lies an ink sac with a duct that drains into the intestine. Most cephalopods have an ink sac.

TYPE
M O L L Y S K I Performed by: Gurov Anton
7 B grade, school No. 49

Moscow 2011

Teacher: Khanova I.B.

ORIGIN OF MOLLUSKS

The problem of the origin of the type of mollusks is debatable. Some biologists derived the hypothetical ancestor of mollusks from annelids, others from flatworms.
Currently, the most widespread hypothesis is the origin of mollusks from primary coelomic trochophore animals, from which annelids also originate. The relationship between mollusks and annelids is indicated by some common organizational features. Thus, a number of lower mollusks have retained the features of metamerism and have a scalene nervous system. In the ontogenesis of mollusks, similarities with annelids inherited from common ancestors (spiral fragmentation, metamerism of some rudiments, etc.) also appear.

MAIN CHARACTERISTICS OF MOLLUSKS I

MOLLUSCS are a large type of animal in terms of the number of species (130 thousand). They live mainly in the seas (mussels, oysters, squids, octopuses), fresh water bodies (toothless snails, pond snails, livebearers), and less often in a humid terrestrial environment (grape snail, slugs).
The body sizes of adult mollusks of different species vary significantly - from a few millimeters to 20 m. Most of them are sedentary animals, some lead an attached lifestyle (mussels, oysters), and only cephalopods are able to move quickly in a reactive manner.
Mollusks are bilaterally symmetrical animals, however, in some mollusks, due to a peculiar displacement of organs, the body becomes asymmetrical. The body of mollusks is unsegmented; only a number of lower representatives show some signs of metamerism.
Mollusks are secondary cavity animals with a non-metameric residual coelim, represented in most forms by the pericardial sac (pericardium) and the gonad cavity. All spaces between organs are filled with connective tissue.

MAIN CHARACTERISTICS OF MOLLUSKS II

The body of mollusks, as a rule, consists of three sections - head, trunk and legs. Very often the body grows onto the dorsal side in the form of an internal sac. The leg is a muscular unpaired outgrowth of the abdominal wall of the body, used for movement. The base of the body is surrounded by a large fold of skin - the mantle. Between the mantle and the body there is a mantle cavity in which the gills, some sensory organs lie, and the openings of the hindgut, kidneys and reproductive apparatus open. All these formations, together with the kidneys and heart (located in close proximity to the mantle cavity) are called the mantle organ complex. On the dorsal side of the body, as a rule, there is a protective shell secreted by the mantle, usually solid, less often bicuspid, or consisting of several plates.
Most mollusks are characterized by the presence in the throat of a special apparatus for grinding food - a grater (radula). The circulatory system is characterized by the presence of a heart, consisting of a ventricle and atria; it is not closed, that is, part of its path the blood passes through a system of lacunae and sinuses that are not formed into vessels. The respiratory organs are usually represented by primary gills - ctenidia. The latter, however, disappear in a number of forms or are replaced by respiratory organs of a different origin.

HABITAT OF MOLLUSKS

Mollusks live in rivers, seas, oceans and other bodies of water, as well as on land - in fields, forests and other land areas

STRUCTURE OF MOLLUSKS

BODY
The body of mollusks does not bear traces of true segmentation, despite the fact that some organs (for example, the gills of chitons and monoplacophorans) may be characterized by a serial structure.
The body of mollusks, as a rule, consists of three sections: head, legs and torso. Representatives of the class Caudofoveata lack a leg. Bivalve mollusks lose their heads for the second time.
The leg is a muscular unpaired outgrowth of the abdominal wall of the body, and, as a rule, serves for movement.
The torso contains all the major internal organs. In the Conchifera group, it grows strongly on the dorsal side during embryonic development, resulting in the formation of the so-called visceral sac.
The mantle extends from the base of the body - an epithelial fold that forms the mantle cavity connected with the external environment. The mantle cavity contains the so-called mantle complex of organs: the excretory tracts of the reproductive, digestive and excretory systems, ctenidium, osphradium and hypobranchial gland. In addition, the mantle complex of organs includes the kidney and pericardium, located next to the mantle cavity.

STRUCTURE OF MOLLUSKS

COVERS
It is believed that in the hypothetical ancestor of mollusks, the integument was represented by the so-called protoperinotum: a cuticle with aragonite spicules. A similar structure of the integument is characteristic of representatives of the classes Caudofoveata and Solenogastres. However, all classes of mollusks, except Caudofoveata, have a ciliated crawling surface - a leg (based on this feature they are united in the Adenopoda group). In Solenogastres, the foot is represented by a pedal groove.
Chitons (Polyplacophora) also have cuticular integuments, but only on the lateral surfaces, called perinatal folds. The dorsal surface is covered with eight shell plates.
In the group Conchifera (which includes the classes Gastropoda, Cephalopoda, Bivalvia, Scaphopoda and Monoplacophora) there are no cuticles and the shell consists of a single plate.

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STRUCTURE OF MOLLUSKS

NERVOUS SYSTEM
The nervous system of mollusks is of the tetraneural type. It consists of a peripharyngeal ring and four trunks: two pedal (innervate the leg) and two visceral (innervate the visceral sac). However, this structure is characteristic only of the lower groups of mollusks: Caudofoveata, Solenogastros and Polyplacophora.
In most other representatives of mollusks, the formation of ganglia and their displacement to the anterior end of the body are observed, with the suprapharyngeal nerve ganglion “brain” receiving the greatest development. As a result, a scattered-nodular type nervous system is formed.
Accommodation occurs due to changes in the shape of the eye - moving away or bringing together the retina and lens.
Smell and taste are not separate.

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STRUCTURE OF MOLLUSKS

CIRCULATORY SYSTEM
Unclosed (except for cephalopods). It includes the heart (the organ that ensures the movement of blood through the vessels and cavities of the body) and blood vessels. The heart consists of a ventricle and one or two atria (the nautilus has 4 atria).
Blood vessels pour blood into the space between the cells of the organs. The blood then collects again in the vessels and enters the gills or lungs.
It is worth noting the unusual bluish color of the blood of mollusks. This color comes from hemocyanin, which has functions similar to those of hemoglobin in the blood of chordates and annelids.

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STRUCTURE OF MOLLUSKS

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STRUCTURE OF MOLLUSKS

EXCRETORY SYSTEM
One, usually two kidneys, in which excretory products accumulate in the form of lumps of uric acid.
They are released every 14-20 days.

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STRUCTURE OF MOLLUSKS

GENITAL SYSTEM
Mollusks can be either hermaphrodite (snails) or dioecious (toothless).
Development can be direct or indirect.
The larvae of some mollusks are called sailfish, or veliger, because they resemble a sail.

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DIVERSITY OF SHELLFISHES

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CLASSES OF MOLLUSCS I

GASTROPODA, a class of invertebrate animals such as mollusks.
The body is divided into the head, visceral sac and leg. The head bears 1 or 2 pairs of tentacles and a pair of eyes. The internal sac and the shell covering it are spirally twisted to the right or (rarely) to the left (asymmetrical animals).
The shell is distinguished by a wide variety of shapes and sculptures: from highly conical to flat-spiral and saucer-shaped; consists of three layers: the outer one is horny, the middle one is porcelain-like and the inner one is mother-of-pearl. In some gastropods, the shell becomes internal or disappears.
The anterior part of the visceral sac is bounded externally by a fold of skin - the mantle. The mantle cavity contains a complex of organs, consisting in primitive forms of symmetrically lying: rectum with anus, two hypobranchial glands, two ctenidia, two osphradiae (chemical sense organs), a heart with two atria and two kidneys.

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CLASSES OF MOLLUSCS II

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CLASSES OF MOLLUSCS III

Biology teacher, GBOU secondary school No. 1022 Kriulina I.V.

Subject: "Class Cephalopods"

Goal: To introduce students to the diversity, lifestyle, and structure of cephalopods

Tasks:

• to form students’ knowledge about the structural features and vital functions of cephalopods;

• develop students’ knowledge about the diversity of the animal world;

• cultivate respect for nature

Write new concepts on the board: “hemocyanin”, “statocysts”, “sexual demorphism”, “autotomy”, “chromatophores”, “ambergris”.

Lesson type: learning a new topic

DURING THE CLASSES:

1.Organizational moment (availability of necessary supplies on students’ tables, greeting).

2.Homework survey: “What was asked for homework?”, “What questions arose about the homework?” Completing tasks using cards taking into account an individual approach.

1 option

1) Mollusks live:

A - only at sea;

B – only in fresh water bodies;

B – in the sea, fresh water bodies and on land ;

G – only on land

2) The mantle is:

A – skin fold located under the concha ;

B – organ of movement;

B – protective shell;

G – section of the body of the mollusk.

3) Bivalve mollusks - inhabitants of water have :

A – gills;

B – lung;

B – have no respiratory organs;

D - they do not breathe, since the valves are tightly closed.

4) Of the listed animals, gastropods include :

A – grape snail ;

B – toothless;

B – oyster;

G – octopus.

5) The excretory organs of the large pond snail include :

A – liver;

B – kidney;

B – intestines;

G – anal opening.

6) The shell, formed by two valves, has :

A – pearl barley, toothless mussels ;

B – squid, cuttlefish, octopus;

B – pond snails, reels, brine;

G – slugs, grape snails.

7) Land snails feed primarily :

A – plant foods ;

B – various invertebrate animals;

B – mollusks of other species;

D – rotting plant residues.

1) Mollusks have two-waybody symmetry.

2) The head may be absent in mollusks leading sedentary or sedentary Lifestyle.

3) Circulatory system of mollusks open

Option 2

No. 1: in each task, choose one correct answer:

1) The shell of a mollusk consists of:

A – lime;

B – only from a horn-like substance;

B – from lime and horn-like substance;

G – from a horn-like substance, lime and mother-of-pearl .

2) They have a single shell, in the form of a turret, curl or other shape :

A – “ship worms”;

B – pearl mussels, scallops, oysters;

B – octopuses, squids, cuttlefish;

G – coils, pond snails, grape snails.

3) The body of mollusks :

A – soft, not divided into segments;

B – soft, noticeably divided into segments;

B – has a dense mucus cover;

G – has a dense chitinous cover.

4) The body of bivalve mollusks is divided into :

A – head, torso and muscular leg;

B – head, tentacles and torso;

B – torso and muscular leg ;

G – head and torso.

5) Pond fish living in fresh water bodies :

A – filter water, clearing it of unicellular algae;

B – help cleanse water bodies of filamentous algae ;

B – are predators;

G – serve as intermediate hosts for various tapeworms.

6) Toothless and pearl barley in reservoirs:

A – purify water from various small organisms and residues suspended in it ;

B – reduce the number of small crustaceans;

D – promote the spread of filamentous algae.

7) Mollusks originated from the ancients :

A – coelenterates;

B – flatworms;

B – roundworms;

G – annelids.

No. 2: fill in the missing words in the sentences:

1) Unlike annelids, the body of mollusks not segmented .

2) The body of the mollusk is covered with a skin fold - mantle.

3) Between the mantle and the body is located mantle cavity .

3. Study a new topic Cephalopods are the most unusual, largest, predatory and most advanced of mollusks. Cephalopods have reached a high degree of development. These are a kind of primates among the invertebrate inhabitants of the sea. Outwardly, at first glance, cephalopods do not resemble their relatives - snails and shells. . These animals were called cephalopods because they have tentacles or “arms” on their heads, which are also called “legs” because mollusks often walk on them along the bottom, like on stilts.

All cephalopods are exclusively marine animals. They live only in oceans and full-salt seas. They are especially numerous in the tropical and subtropical regions and in temperate latitudes. Mollusks, like many fish, swim freely in the water column, others prefer to hide at the bottom.

The sizes of cephalopods are very diverse - from 1 cm to 18 m. The body of cephalopods is bilaterally symmetrical, their shell is underdeveloped and they wear it not outside, but under the skin of their back. The underdevelopment or even disappearance of the shell is associated with the high speed of movement of mollusks.

The method of movement of cephalopods is interesting: by pumping water through itself, the cephalopod glides in the azure waters, like a rocket with the back end of the body forward in a reactive manner. The speed can reach 50 km/h.

The internal structure of cephalopods is represented by various organ systems . Let's consider it using the example of an octopus.

The digestive system consists of a mouth opening, which has horny jaws curved like a parrot's beak. The tongue is located in the pharynx, and on it is a grater, with the help of which the animal grinds food. The ducts of the poisonous salivary glands flow into the pharynx. A thin esophagus runs from the throat to the stomach. Along the way, it pierces the brain. There is a liver and pancreas. The digestive juices they secrete digest food within four hours. The long intestine following the stomach ends in the anus.

The main food of cephalopods is fish, crabs and shells. But many species also eat carrion. They also eat each other. And hunger is not always the cause of cannibalism. Therefore, even Aristotle, reflecting on such bad customs, decided that mollusks eat each other in order to maintain their vitality: an octopus that has not tasted octopus meat seems to wither and die.

The respiratory system of mollusks is represented by one pair of gills located in the mantle cavity; they also ensure gas exchange in the animal’s body.

The circulatory system of cephalopods is almost closed, consisting of arteries, capillaries, veins and the heart. The heart consists of two atria and a ventricle and beats 30–36 times per minute. The blood of mollusks is unusual - blue. Instead of hemoglobin (as in mammals), the blood of cephalopods contains hemocyanin. Copper, which is part of hemocyanin, gives their blood a bluish color.

The kidney is the excretory organ of cephalopods; it is located in close proximity to the gonad.

The nervous system of cephalopods is more complex than that of all other invertebrate animals and is quite highly specialized. Brain cells tightly fit the esophagus on all sides. Therefore, mollusks, despite their very predatory appetites, cannot swallow prey larger than a forest ant. This is where a grater comes to their aid, with which they prepare “puree” from crabs and fish.

Cephalopods have well-developed sense organs ). The eye of an octopus is not much different from the eye of a mammal or even a human. None of the inhabitants of the sea have such keen eyes as the octopus and its relatives. Only the eyes of an owl, a cat, and a human can compete with them. On one square millimeter of the octopus's retina, there are about 64 thousand visual elements that perceive light. And the size of the eyes of cephalopods is record-breaking. The eye of a cuttlefish is only 10 times smaller than itself; for comparison, the eye of a thirty-meter blue whale does not exceed 10–12 cm in length.

The octopus's sense of taste is so developed that it apparently recognizes its enemies by taste. The entire inner surface of the tentacles and each sucker are involved in tasting food.

If you cut into the cartilaginous skull of an octopus, inside you can find two bubbles containing lime crystals. These are statocysts – the organs of hearing and balance.

Regarding reproduction, it must be said that cephalopods are dioecious animals. There is also such a phenomenon as sexual demorphism, i.e. differences in body structure and size of male and female. Fertilization occurs in the female's mantle cavity. The eggs of cephalopods are large and rich in yolk. Hatching females do not eat anything for about two months, sometimes more, until they hatch their young, which they also protect, clean and provide them with an influx of fresh water. Typically, cephalopods reproduce once in their lives, after which they die.

Cephalopods have many protective devices: their tentacles are lined with hundreds of suckers, and many squids also have claws like cats; they have no teeth, but do have a beak. Four to six kilogram squids easily bite through the wire fishing line of a spinning rod. There is in the arsenal of protective devices the oldest means of life insurance - autotomy, i.e. self-mutilation. On occasion, the strong tentacles contract with such force that they tear themselves apart. The tentacle falls off, as if cut off by a knife, and the predator receives it as a ransom for life.

In the process of evolution, cephalopods acquired an even more amazing miracle weapon - an ink bomb. In a moment of danger, the mollusks eject a stream of inky liquid. The ink spreads in the water like a thick cloud, and under the cover of a “smoke screen” the mollusk escapes safely. Ink is produced by a special organ - a pear-shaped outgrowth of the rectum - the ink sac. Not all the contents of the ink sac are sprayed out at once. An ordinary octopus can set a “smoke screen” six times in a row, and after half an hour it completely restores the entire spent supply of ink. Observations have shown that discarded ink does not dissolve immediately, not until it hits something.

All cephalopods have elastic, rubber-like cells under their skin. They are filled with paint, like watercolor tubes. The scientific name for these cells is chromatophores. Chromatophores contain black, brown, red-brown, orange and yellow pigments. An irritated octopus can go from ash gray in a second to black and back to gray. If it occurred to someone to organize a chameleon competition, the cuttlefish would probably win the first prize.

Cephalopods are quite diverse animals. Here are just a few representatives of these animals. The economic importance of cephalopods is also important. They have been used as food for a long time. However, out of six hundred species of cephalopods, only one to two dozen are objects of intensive fishing. In terms of basic nutritional indicators - calorie content and protein composition - squid, especially canned ones, are superior to all other shellfish and even some fish consumed. They are slightly inferior to beef and veal.

Small squids in Japan are not thrown away, but are used for fertilizer, livestock and poultry feed.

Precious ambergris, a wax-like substance that is used in perfumery as a fixative for the aroma of perfumes, is formed from compacted squid beaks that have passed a certain stage of decomposition.

4. Consolidation of what has been learned.

• Formulation of the conclusion to the lesson: “Cephalopods are a small group of highly organized animals, distinguished by the most perfect structure and complex behavior among other mollusks” work in workbooks

5. Summing up the lesson.

• What new did you learn in today's lesson?
• Assessment of students' knowledge (with commentary).

6. Homework

Akhmetova Madina Sabitovna –

Biology teacher SSL No. 5

them. M. Lomonosov, Taldykorgan

Class 7

Topic: “Octopus, squid, cuttlefish. Features of their structure. Role in biocenosis and practical significance.”

Target:

To form a concept about the lifestyle, structure and diversity of cephalopods.

Tasks

Educational: continue to develop the skills to analyze and justify the answer; establish cause-and-effect relationships.

Developmental: Develop the biological horizons and communication skills of students. Develop the ability to work in groups.

Educational: Fostering environmental literacy and love for living nature.

Form of organization of educational activities

Collective-individual, group

Expected results

Students will learn:

Set a learning task under the guidance of a teacher; Plan your activities under the guidance of a teacher; Work in accordance with the assigned task and plan; Evaluate your personal results: Express judgments, search and select information; Analyze connections, hypotheses;

Equipment

computer, multimedia projector and screen, multimedia presentation,

Lesson stage

Teacher's actions

Student actions

I . Organizing time (3 minutes)

Goals:

Creating conditions for students to develop an internal need for inclusion in educational activities

Greets students
“Smile at each other and mentally wish success to yourself and your friends”

Division into groups:

"Puzzles"

Greeting the teacher and each other

Collect puzzles and thus divide into 4 groups

II . Updating knowledge (10 minutes)

Target: organize knowledge updating

Hot chair: thick and thin questions - 3 questions each

A student comes out from each group and answers questions.

The groups then rate each other on the marking sheet.

L Formation of skills and abilities

In Call: 1 min

Understanding:

3 min

2 minutes

20 minutes

3 min

Statement of lesson purpose

Question: what animals did you get as a result of putting together the puzzle? What class of molluscs do they belong to?

View Presentation – Cephalopods –

RAFT strategy

Before starting work, students are asked to create assessment criteria.

1. group Octopuses –

Grandmothers are gossiping on a bench.

Group 2 Squids – Students discuss the topic in the chat.

Group 3 Cuttlefish –

Fishermen fishing for cephalopods.

4.group Cephalopods. Cephalopods on the ocean floor.

Peer assessment of groups

Students answer the question and formulate the topic and goals of the lesson.

Highly motivated student showing prepared presentation

Together they draw up evaluation criteria.

Students analyze information from various sources, write a script, assign roles in a group, and act out skits.

Groups evaluate each other according to criteria.

Reflection on learning activities in the classroom

(2 minutes)

Goals:

Record new lesson content;

- organize reflection on your own educational activities

"Tell me three things"

Express your opinion which should consist of 3 words

Lesson

I'm in class

Bottom line

1. interesting

2.boring

3.don't care

1worked

2 had a rest

3helped

others

1understood

material

2found out

more than I knew

3didn't understand

Students answer questions on sticky notes.

Homework

1 min

Target:

- organize homework

Create a crossword puzzle on a topic

Students write down the assignment in their diary.