Presentation on biology "class of cartilaginous fish". Class Cartilaginous Fishes Class Cartilaginous Fishes. A perfectly streamlined body shape, a fantastic sense of smell and razor-sharp teeth - all this makes the shark the most. Presentation on the topic of cartilaginous fish

“Electric Stingray” - Electric stingrays have always excited people’s consciousness. Each new discharge becomes weaker and weaker, and then the batteries completely run out. Electric ramp. Electric stingrays feed on fish, which they wait for, buried in sand or silt, and stun at the first convenient opportunity. One electric discharge, capable of killing a fish and hitting a person, lasts three hundredths of a second, but stingrays prefer to give a series of charges - from 12 to more than 100 in a continuous “burst”.

“Classification of fish” - Cartilaginous fish are divided into two subclasses: Elasmobranchi and Holocephali. Manta sea devil. Excursion to the world of ichthyofauna. You can tell the age of a fish by its scales. Are the gill slits covered?______. Warm up. The skeleton partially or completely becomes bone. Determine the systematic position of the fish.

“The structure of lungfishes” - The first lungfishes. African protopters. Protopter. Chord. Questions. Lungfish. The structure of lungfish. Lepidosiren. Horntooth. Lifestyle.

"Subclasses of Fish" - Shark Squad. Classification of fish. Chimera Squad. Phylum Chordata. One of the most ancient vertebrates. Presence of a skull and hard skeleton. Subclass Whole-Headed Chimera Squad. Variety of fish. Subclass Whole-headed. Phylum: Chordata Class: Fish. Squad Stingrays. Subclass Lobe-finned fish. P/type Vertebrates. Subclass Sturgeon.

“Bone-cartilaginous fishes” - Herring-like fish. Batoidea) contain five orders and fifteen families. Bony fish. Stingrays (lat. Scourge-shaped tail. Sturgeon-shaped. Salmoniformes. Today about 20 thousand species are known. Perciformes) number over 6,000 species and about 150 families. Sharks. Stingrays. Perciformes. Fish live only in water.

“Shark Squad” - The most common shark of the tropics, man-eater, scavenger, about 9m. Sharks' eyelids close upward. The retina of the eye contains pigment cells. Appeared about 300 million years ago. The meat has an unpleasant odor. Features of the external structure of sharks: Usually 5-7 pairs of gill slits. Mako shark teeth. The spike (35cm) at the end of the tail contains poison that is fatal to humans.

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Presentation to the lesson on the topic "Cartilaginous fish". Conducted in 7th grade. Each slide reflects the main points of studying a new topic. The children liked the angler fish the most among the cartilaginous representatives))))))))).

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“Presentation for the lesson Cartilaginous fishes”

Superclass of fish.

Class Cartilaginous fish

Ichthyology (from Greek. ichthys- fish, logo- doctrine) - a branch of zoology that studies fish.

External structure of fish

Body Shape

Body covered

Body parts

Organs of movement

Determining the direction of water movement

streamlined

scales and mucus

head, body, tail

fins

Side line

Internal structure of fish

gills.

one circle of blood circulation two-chambered heart.

trunk buds.

head dorsal

Superclass Pisces

Cartilaginous fish

Bony fish

The class Cartilaginous fish has about 750 species.

Main features:

1. Cartilaginous skeleton

2. No gill covers

3. No swim bladder

4. Scales with teeth covered with enamel (placoid)

5. Pointed head shape

Cartilaginous fish

subclass

Elasmobranchs

(sharks and rays)

subclass

Whole-headed

Laboratory work External structure of fish

1. Consider the external structure of the fish. Sketch.

2. Find: head section, gill cover, lateral line, fins, tail.

3. Label the found parts of the body in the drawing.

4. Conclusion: Fill out the table “adaptation of the external structure of fish to living in water.”

Fin

Back Forward

Attention! Slide previews are for informational purposes only and may not represent all the features of the presentation. If you are interested in this work, please download the full version.

Lesson type: formation and consolidation of new knowledge.

Target: familiarization with the general characteristics of the class, the diversity and features of the structure and behavior of the orders of sharks, rays, and chimaeras.

Tasks:

• learn the main characteristics of cartilaginous fish;
• understand the classification;
• identify features of adaptation to the environment;
• learn the meaning in nature and in human life;
• be able to recognize representatives of the orders Sharks, Rays and Chimaeras;
• develop the ability to observe animals while watching a video clip;

Teaching methods:

According to the source of transmission and perception of educational information:

• verbal (story, conversation);
• visual (illustration, demonstration);
• practical (test, exercises).

According to the degree of management of educational work:

• educational work under the guidance of a teacher;
• independent work of students;
• working with a textbook;
• practical control and self-control.

Form of organization of students' educational activities:

• frontal
• individual
• steam room

Equipment:

• illustrations depicting representatives of the type,
• computer,
• screen,
• multimedia installation,
• Power Point presentation.

Lesson progress

I. Organizational moment.

- Let's sum it up. Slide 5

– Origin. Slide 6

• Related to ancient armored fish
• The primitive antiarchs had their entire body encased in a shell of skin plates;
• In carnivorous arthrodir the shell covered only the front part of the body.
• Armored fish are the first jawed fish; their jaws arose from gill arches that moved closer to the mouth, and consisted of pointed bony plates.
• Armored fish became extinct at the end of the Devonian.

2. Characteristics of units.

Sharks. General characteristics slides 7-8

Variety of sharks. Slide 9-13, film clips slides 10,slide 12

Gymnastics for the eyes slide 14

1. Blink quickly, close the gas and sit quietly, slowly counting to 5 (4-5 times)
2. Close your eyes tightly (count to 3) Open and look into the distance (count to 5) (4-5 times)
3. Make 3-4 circular movements with your eyes to the right side, then to the left. Look into the distance at the count of 1-6. (1-2 times)

Stingrays(Explanation by the teacher with elements of conversation.) slides 15-17

Look at the photo. What features of adaptation to the environment did you see?

Chimeraformes(Explanation by the teacher with elements of conversation.) slides 18-19

Additional material for teachers (See. Appendix 8)

IV. Consolidation of knowledge

slide 20

Work in pairs (check with each other)

Answer on the board

slide21

What order do these fish belong to?

A perfectly streamlined body shape, a fantastic sense of smell and razor-sharp teeth - all this makes the shark the most terrible marine predator. Sharks have lived on Earth for 350 million. years and during this time little has changed. A shark must always be in motion - it breathes oxygen, which is taken by its gills from the oncoming flow of water. And besides, the shark does not have a swim bladder to keep it in the water. Unlike other fish, sharks and related rays have a cartilaginous rather than bony skeleton. Stingrays have a flat body, on the lower side of which there is a mouth with flattened teeth: with them the stingray chews the shells and shells of bottom animals. Stingrays swim gracefully at the bottom, flapping their huge wing fins.

Sharks SHARKS-mako. The body length of a mako can reach 3.5-4 m, and its weight is 450 kg. The back is dark blue, the belly is white. Sharp and thin teeth have smooth edges. Makos are common in the tropical waters of the Atlantic, Pacific and Indian oceans. They are considered the fastest of all known shark species and are capable of jumping above the surface of the water. Makos feed on cephalopods and various, sometimes very large, fish. Remains of swordfish are found in the stomachs of some large individuals. Makos pose a real danger to swimmers and can also attack small boats. The commercial importance of these sharks is small, but they are an object of sport fishing.

Whale shark The largest living fish is the whale shark, reaching a length of 20 meters. This huge but harmless creature feeds, like whales, exclusively on zooplankton. The egg capsules of this shark reach almost 70 cm in length and 40 cm in diameter.

White shark The largest predatory fish is the white shark, or man-eating shark. Its length can exceed 9m, and its weight is 2.7t. The white shark plows the ocean, swimming more than 480 km every day, and devours any living creature, often swallowing it whole. The great white shark sometimes attacks people.

The shark moves mainly by its tail. The oscillations of the upper blade of the tail push the shark forward, and the characteristic slope of the pectoral fins keeps it horizontal. The shark does not know how to instantly stop the movement of its fins. To stop, she turns sharply.

Hammer Shark Among all the inhabitants of the sea that attack humans, the most terrible is the shark. Bloodthirsty, cunning and lightning-fast, she struck fear into people at all times. The hammerhead shark is one of the largest sea creatures. Its average size is 4-5 meters, but you can also find those whose size exceeds 7 meters. The world's largest hammerhead fish, 7 meters 89 centimeters long and weighing 363 kilograms, was caught off the coast of New Zealand.

Tiger Shark Deep in the wilds of the sea, whose outfit is very unremarkable, awaits a new victim. It could be a turtle, a gaping sea gull, or even a person. Unlike other sharks, the voracious tiger shark with its huge jaws will try to eat everything that comes its way. It will even bite through a wooden boat or iron sheets. Simple tiger-like stripes provide the shark with camouflage, which is how it got its name. The more we learn about this bloodthirsty shark, the more menacing features it acquires in our eyes.

Nurse shark NURSE SHARK, a cartilaginous fish of the carpet shark family. Body length from 2.5 to 4 m, weight kg. The color is uniform, yellowish-brown; in young individuals, small dark spots are scattered throughout the body. It lives in the Atlantic Ocean off the coast of America from Florida to Brazil, off the coast of West Africa, as well as in the eastern part of the Pacific Ocean. Usually found in schools of up to 40 individuals near the shore, at a depth of up to 3 m. These slow and inactive sharks feed on octopuses, crabs, shrimp, sea urchins, and small fish. As a rule, it is not dangerous for humans. However, there are known cases of provoked attacks on swimmers. At the same time, it holds a person’s arm or leg with a death grip and does not unclench its jaws even after being removed from the water.

Katran sharks The Katran, or common spiny shark, is one of the most widespread sharks of temperate latitudes. Following the movement of forage fish, it makes long-distance migrations along the Atlantic coast of the United States and in the eastern part of the Sea of ​​Japan. In Russia it is found in the Black, White, Barents and Far Eastern seas. Length 2 m, weight 15 kg. Leads a benthic, schooling lifestyle and rises to the surface of the water at night. It feeds on fish and squid. Katran does not attack humans, but its spines in front of the dorsal fins are weakly poisonous, and an accidental prick from them is very painful. In some places it reaches high numbers and seriously harms fishing, tearing gear and eating fish in nets. At the same time, it itself is a commercial fish, the world catch is about 30 thousand tons per year. The special value of katran is that its meat does not have the unpleasant odor characteristic of many sharks.

Sea fox The length of this shark is up to 6 m. It lives mainly in the warm coastal waters of the Atlantic and Pacific oceans, but sometimes swims further north in the summer. A sea fox swims in a circle, driving away a school of fish with its tail. Then, opening her mouth wide, she pounces on them and devours them.

Reef sharks An adult of this family is about meters long. The gray reef shark's body is shaped like a torpedo, which allows it to be very fast and perform rapid maneuvers. As for the appearance of the shark, they usually have a gray color of various shades with a black stripe on the tail. The main victims of these predators are reef fish. However, in addition to them, it also feeds on crayfish and cuttlefish. This type of shark prefers to feed a short distance from land. The gray reef shark often attacks humans. It causes fear for many. This shark becomes enraged by a small drop of blood in the water or vibrations, and it begins to aggressively try to bite the victim, even if there is no one nearby.

Bull shark The bull shark often enters fresh water, upstream of large rivers. It is very dangerous for humans, especially when encountered in a confined space. This shark is medium in size, but aggressive, unpredictable and fast in its movements. These sharks have a rounded snout, as well as eye bulges, from which it gets its name. Bull sharks have common anal fins, as well as two fins located on the back. It is worth noting that they are covered with thorns. Among other things, they have 5 gill openings. These sharks themselves are small in size. The largest species among these sharks is the Port Jackson bull shark. The shark measures about 1.65 meters in length. These sharks prefer to live in warm temperate regions, as well as in the tropics. Their main distribution areas are the Indian Ocean and the eastern Pacific Ocean.

Largemouth Shark Since its discovery in 1976, this deep-sea shark has remained the only species in the largemouth shark family. Until November 2004, fewer than 25 specimens were observed, of which only a few have been scientifically studied. Very little is known about the anatomy, behavior and range of this shark. The largest specimen measured was a dead female measuring 5.63 m, which washed ashore on April 19, 2004 near the city of Ichihara in Tokyo Bay. The smallest specimen was a male caught on March 13, 2004 near the island of Sumatra, whose size was 1.77 m. The most noticeable external feature, to which the largemouth shark owes its name, is a relatively large rounded head with a short nose and a huge mouth. The color of its back is dark brown, the shark has two dorsal fins, one asymmetrical caudal fin, two large pectoral fins and two fins on the stomach, of which the rear pair is much smaller.

Stingrays Shark-tailed stingrays are a family of cartilaginous fish of the superorder stingrays, which includes two genera. In terms of body shape, representatives of this family occupy an intermediate position between sharks and rays. They have a flattened body, the tail part is almost not separated from the body. Along with an elongated snout, these rays are characterized by a two-lobed fin with pointed ends, reminiscent of the tail fin of sharks. Shark-tailed rays are common in tropical waters off the coasts of Africa, Asia and Australia. One of the species, the shark-tailed ray, is of commercial importance. Its length is up to 3 m, weight up to 225 kg. The main food is bottom invertebrates.

Sea devil Sea devil is the largest stingray. Unlike most stingrays, the devil swims in the water column, smoothly flapping its pectoral fins, reminiscent of the wings of a huge bird. The span of these “wings” can reach almost 7 meters. The sea devil gets its name from its horn-like head fins. With these fins, the stingray forces water rich in zooplankton and small fish into its mouth.

Origin

On the left is one of the armored fish - bothriolepis.

On the right are the jaws of a fossil Carcharadon shark.

• ancient group of fish.
• Sharks and rays
• 600 species
• Cartilaginous skeleton
• The body is covered with bone scales

• Sharks include fish with an elongated torpedo-shaped body and a length of 20 cm to 20 m. The skin of sharks is rough, covered with numerous denticles. The paired pectoral and pelvic fins are located horizontally and allow the fish to move up and down. There are underdeveloped eyes on the head, capable of seeing objects only in black and white.

• The respiratory system begins with 5–7 pairs of gill slits.
• In the intestine, a spiral valve stretches along its entire length, increasing the absorption surface.
• The arterial cone of a two-chambered heart is capable of independent contraction and provides an additional impulse of blood.
• The sense organs are represented by the organs of smell, vision, touch (lateral line)
• Fertilization in almost all cartilaginous fish is internal.
• Many of them have a cloaca.
• Cartilaginous fish are viviparous or lay eggs.

The most dangerous sharks

White shark

Hammerhead shark

• These are relatively large fish, some of them reach a width of 6 - 7 meters and a mass of 2.5 tons. Their body is flat, flattened in the dorso-ventral direction, diamond-shaped - with pectoral fins fused and expanded on the sides. The caudal fin has the appearance of an elongated thin whip. Some stingrays have smooth skin, but many have scales and spines similar to those of a shark.

• Gill slits are located on the ventral side
• The body is strongly flattened.
• Wide pectoral fins grow to the edges of the body and head. The caudal fin is thin, and its blades are often reduced. The anal fin is absent.
• They use their pectoral fins to move, flapping them like wings.
• The squirts are much better developed than those of sharks.
• Most species are inhabitants of the seabed, which is why their backs have a protective color that matches the color of the soil.
• Stingrays reproduce by laying capsuled eggs on the bottom or by viviparity.

• Some species of stingrays have electrical organs.
• The discharge lasts 0.03 seconds with a voltage of up to 220 V.

European chimera

American hydrolag

• The jaws are completely fused with the skull.
• The gill slits are covered by a fold of skin.
• There is no cloaca, the anal and urogenital openings are separated from each other.
• The naked body is up to 1.5 m long, gradually becoming thinner, turning into a long tail.
• They live from the shelf to the great depths of the World Ocean.
• Chimeras feed on marine invertebrates and fish.
• They have practically no commercial significance.

Test task "Wave"

1) in cartilaginous fish, the gills are closed by cartilaginous

lids;

3) most rays are bottom-dwelling

4) sharks and rays lead a bottom-dwelling lifestyle;

5) all sharks are dangerous to people;

6) cartilaginous fish have highly developed muscles;

7) cartilaginous fish have a swim bladder;

8) the skin of cartilaginous fish is covered with scales;

9) the body of stingrays is torpedo-shaped;

10) the coloring of stingrays is protective.