Message about medicals on biology: a definition where they live, what they eat, how they move, multiply, how much live?

In this article you will find interesting information about jellyfish for messages by biology.

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Looking at the jellyfish, at her smooth movements in the water column - she fascinates. These animals are almost completely consisted of water, reproduce copies of themselves, and old, can become young. Typical representatives of Medus - Aurelia. They are found everywhere in shallow water around the world. Interesting facts about jellyfish read in another article on our website.

If you need to write a message about these animals in biology to school 3-7 grade, look for all the necessary information below. Read further.

What is a jellyfish in biology: a definition for a message by biology

What is a jellyfish in biology? Here is a definition for a message by biology:

Medusa is a symbiosis of intestinal organisms freely paid in the aquatic thickness.
More often, these are multicellular organisms of hydroid -type scyids and cubesis.
Together, they represent a single organism, which is called a jellyfish.
It looks like a bell, a saucer or an umbrella.
The intestinal body resembles a dome or sphere on top.
In the lower part of most of these creatures, tentacles are located, with stinging cells, to which it provokes a bonding. Pro read the bites of these marine inhabitants at this link.

Meduses are growing all their lives. Their dimensions vary from several millimeters to two and a half meters in diameter. The tentacles of individual species are reached in length 35 meters.

Medusa: Which group of animals belong to?

A living organism, called a jellyfish, consists of phases of three groups of animal body life:

Hydromeduza - Type of jellyfish, attracting specialists with its immortality. A mature jellyfish exists in the form of a polyp, and it is this property that makes it immortal. She is able to stop the life cycle, turning it back.
Kubeduza - This type of jellyfish is most poisonous and is the greatest danger to humans.
Szifomeduza - Some types of jellyfish of this type are able to attach to underwater objects, and sometimes to animals, this contributes to their migration. Most, they are all poisonous.

All these creatures belong to intestinal.

By the type of power: intestinal jellyfish predators or not?

Intestinal jellyfish predators precisely by the type of nutrition. Many of them are more likely passive hunters:

They freeze in the water column, waiting for the victim and striking it with stinging cells.
Getting into the tentacles, the victim instantly digested before, before Medusa will fall into the mouth.
Some species act skillfully, and pursue the victim until they catch it.
The animal's mouth is located in the lower part, i.e. Under water, production is caught by processes.
Many jellyfish on processes have cells that produce paralytic poison.
Some species simply draw into themselves a large amount of water and choose a substance suitable for food from this.

This is the most large type of predators on Earth.

Medusa: Where does it live, why can't you live in fresh water?

Organisms of this population live only in salt water. You can see them everywhere - from the Arctic and Antarctic latitudes, to equatorial.

They are in salty lakes and closed lagons, coral reefs are also abounded in jellyfish.
Many representatives of the species love warmth, and their favorite habitat is superficial water.
The view lives in fresh water CraSpeDacusta SowerbyiThis is in the forests of the Amazon.
This species settles around the world thanks to sea transport.

In fresh water, they cannot live due to often changeable temperature and strong currents that jellyfish cannot cope with. Preferences in freshwater species are standing water of lakes and reservoirs.

How and what do jellyfish eat?

Medus diet includes:

Their smaller individuals
Eggs of creatures living in the water thickness
Zooplankton
Fish fry
Fish caviar
Small crustaceans

Medus does not have a digestive tract, so all the food enters the cavity inside the body and with the help of special enzymes there is a digestion of swallowed organics. Medus does not have teeth, she does not need to catch the prey larger than herself. She catches or chases what will fit in her mouth.

Small specimens are satisfied with the fact that it does not have any resistance, and who is larger - they hunt brothers and small fish. The largest representatives eat more than 10 thousand fish in all my life.

How much percent of the Medusa body consists of water?

The jet body of the jellyfish on 95% consists of water. The rest is proteins, cells of nervous tissue and muscles. It is clear that the creature cannot live on land: the jellyfish extracted on land will dry. Her body consists of three main layers:

The outer layer is the cells of the outer surface, there are germ cells and cells that perform the motor function.
The inner layer contains digestive cells that form an organ resembling a bag.
The lower layer includes the mouth of the jellyfish. It has different forms and size, depending on the type of jellyfish.

Since the animal consists mainly of water, it does not have a heart, a circulatory system, a gills. This invertebrate also does not have a brain and visual analyzer.

How is a jellyfish, is there and where she has bones, blood, breathing organs, heart, brain, eyes?

Medusa mucous body is very interesting:

It is two -layer, the layers are connected by an adhesive substance.
It is the body that is responsible for the functions performed.
In the outer layer there are cells responsible for movement and reproduction. This part of the body is smooth and mainly convex.
The inner layer is needed to digest food. It resembles a bag in shape.
At the bottom of the jellyfish dome is a mouth. It is by its location that one can judge the form of a jellyfish - it is significantly different in the structure.
Separately deserves the attention of an umbrella. The tentacles are located along its circle.
Depending on the type of jellyfish, they can be of different lengths and thicknesses, up to the filamentous ones.

The organ of vision and equilibrium is a set of nerve cells that respond to the light and position of the body of the jellyfish in water. It turns out that this creature does not have an eye. There is also no heart and brain. She breathes with her whole body, respiratory organs and gills, like fish. There are also no bones and blood.

Does the jellyfish have a nervous system, the senses: where is the accumulation of nerve cells?

The nervous system of the jellyfish is represented by cells spread mainly around the mouth and along the edge of the umbrella. There are eight nerve nodes in total:

They are located along the edge of the umbrella near the tentacle.
The accumulations of nerve endings and cells in invertebrates are called ganglias.
Unlike polyps, the nervous system of jellyfish is much more complicated.
In addition to the subcutaneous nerve endings along the edges of the umbrella, there are clusters of the ganglia, which, together with processes, form a continuous ring from the nerves.
It innervates muscle fibers, as well as sensory organs along the edge of the umbrella.

The senses include the so -called Ropalia is shortened tentacles located along the edge of the jellyfish bell. There are two sensitive organs - vision and balance. With the help of equilibrium (statocists) organs, the creature feels an approaching storm, and the animal goes to a greater depth.

Does Medusa have an excretory system?

Medus does not have an excretory system. The remains of not completely digested food are released by the cells of the ectoderm (the company takes part in this). This is also done using a special intermediate cell.

The structure, what kind of organ and the jellyfish is the most similar?

Oddly enough, but Medusa and Man have identical systems. The structure, what kind of organ and the jellyfish is the most similar?

This is an equilibrium body.
Statocysts in their functionality are most similar to the semi -coil channels of the human ear.
The structure of sensitive cells of statocists is the same with sensitive hairs of similar organs of highly developed animals, including vertebrates and humans.

Inside, the statocyst is filled with liquid in which the otoliths move. When the body position changes, the epithelial cilia irritates. Nervous impulses go along the fibers of the nervous system to its central part and causes a movement reaction aimed at leveling the equilibrium position.

What is the name of the outer layer of the cells of the jellyfish?

In a jellyfish, the outer layer of body cells is called ectoderm. All of them are differentiated. Intravenous, muscular epithelial cells have processes that can contract. They are located on Medusa along her body. When cells are reduced, the body of the body shortens and becomes thicker, and relaxing stretches. Intercial (small) cells undifferentiated. They are located between muscular epithelial cells. They have few cytoplasmas and there are large nuclei, they provide regeneration.

Stripping cells lie over the entire outer surface of the jellyfish, concentrated in the majority on tentacles. They perform a protective function. Contain a capsule with poison and a stinging thread. There is a tactile hair, with irritation of which the stinging thread is quickly straightened. After the cell is triggered, it dies and a new one forms in its place.

What function does the intermediate cell in the jellyfish perform?

The function of the intermediate cell in the jellyfish is akin to stem cells in mammals and humans. This universal manufacturer performs a unique function, supplying undifferentiated cells to the body. They, depending on the need, can become nervous, muscle or muscular. All intestinal cells have this type of cell. Their main function is the production of cells for various parts of the body of the creature.

For example, they participate in the process of regeneration of stinging cells.
When using them (cells die out), replenishment of germ cells after reproduction is performed.
From these cells, the used reserves of the body are replenished.

These are universal manufacturers of the structures of the body of a jellyfish that supply into each layer undifferentiated cells that transform the necessary type of cells in the right place.

What is the name of the equilibrium in jellyfish?

The equilibrium organ in jellyfish is called statocists. Statolytes or otolites displaced in statocysts filled with liquid, when the body of the jellyfish changes, annoy sensitive epithelial cells. A nervous impulse from them indulges in the fibers of the nerve into the central nervous system, which causes the reaction of movement, which is aimed at correction of equilibrium. It is worth knowing:

Studying the anatomy of the jellyfish, we can say that they have a well -developed nervous system.
At the same time, they have no brain - a regulator of all life processes.
The fact of maintaining equilibrium in jellyfish is interesting.
Turning over, the animal upside down can be seen along the edges of the so -called umbrella. The regional body.
These same statocists are located in it.
Their nature is mechanotropic.
The animal recognizes sounds in the range 3-12 hertz, And in case of their occurrence, rushes to the depth.

In conclusion, it can be argued that one or another part of the body of the jellyfish is associated with the function that it performs.

How do jellyfish move, what is the name of their movement?

The method of movement of these jellyfish is called "reactive". How do jellyfish move? Here's the answer:

Relaxing an umbrella or dome, the animal drags a certain amount of water under it and then reducing it, pushes water from under the dome with force, giving his body a push.
This principle is similar to the principle of operation of the reactive engine.
The difference with the engine is that Medusa has a movement due to an impulse, and the engine has constant traction.

The reactivity in the movement of the jellyfish occurs due to the muscles of the crown located in the lower part of the bell. Going up, the muscles push out the water from under the jellyfish, giving it a motor impulse.

How do jellyfish propagate?

Propagation in most jellyfish occurs sexually. Pink and purple gonads in males, yellow in females. Male cells through the rotary hole are released into the water, and after that, some part, it enters the body of the female, where it is fertilized. The egg is generated in the planum, which is subsequently attached to the bottom objects, and then turns into a polyp. Next, the polyp begins asexual reproduction. It is divided into several fragments, which later turn into small jellyfish. In the life cycle of Medusa, its true form prevails, and the polyp is an intermediate link in this chain.

There are also types of jellyfish that are separately. They have 4 gonads (sex glands). Propagation occurs as follows:

An adult jellyfish forms gametes (germ cells).
They merge with the formation of a zygote, from which a larva is then formed - planning.
She settles in one place and attaches to the substrate.
Then a polyp is formed, which, in turn, begins to multiply by the budding and strobulation, as a result of which the broadcasts (young jellyfish) are formed.

Younger develops and turns into an adult individual that can already form gametes, and the process can be repeated endlessly.

How long do jellyfish live?

How and how much the life of the jellyfish lasts depends on its habitat. In the natural environment, their duration could be longer if they do not encounter the problems and dangers of the laid in any of any inhabitant of the oceans. It is worth knowing:

In captivity, the content of jellyfish may be short.
It is not easy to breed jellyfish at home, in the aquarium.
They are contraindicated in sunlight, for breeding jellyfish, they need a separate aquarium with sea water, they need a specific food that cannot be bought in an ordinary pet store.

With proper care, the home jellyfish will live 1 to 2 years old. In the natural environment, jellyfish can live more than 15 yearsbut it depends on the type. The dangers that are in wait for the jellyfish in the open sea in the majority determine the duration of their life and more often in a large way.

What are jellyfish in the sea, what is the benefit of jellyfish?

Meduses are needed in the sea to clean water

Nature does not tolerate excesses and, if jellyfish exist, then it should be. What are jellyfish in the sea, what is the benefit of them? Here's the answer:

Passing water through themselves, jellyfish make it cleaner and suitable for other marine inhabitants.
This is food for some birds and fish.
The tentacles of individual jellyfish are a shelter for fry and small fish.
These creatures of the link of the food chain. They are predators, catch prey, eat plankton and the remnants of organics.

Values \u200b\u200bfor humans:

The aesthetics of the jellyfish fascinates the observer. Observing them in the aquarium, they have a beneficial effect on the psyche.
Many Asian peoples eat them, they are preserved and served dried.
Medies receive medicines to combat oncological diseases.
According to the behavior of these creatures, the weather is predicted.

By jellyfish, you can even determine when there will be a storm and much more. Read further.

Do you portend a storm or storm, swimming close to the shore?

Meduses swim near the shore or not far from it because there is a lot of food for her and a comfortable water temperature. When she swims close to the shore, you can be sure that in the near future the sea will be calm or will be calm. Therefore, it can be said with confidence that jellyfish portends good weather and calm when they approach the shore.

It is worth knowing: When the cyclone is approached or its fronts, and if the thunderstorm also begins, the outer shell of the body feels a change in atmospheric pressure. This instinctively makes her float to the depths in order to avoid the approaching storm threatens to throw the jellyfish ashore.

The closing of the environment caused by mechanical nature, the animal feels with the body, and the tentacles react to other stimuli, including electric ones. The jellyfish is similar to the laboratory, which is an indicator of water in the sea. She reacts to the external environment and changes her movement, obeying instinct. So there will be a calm or a storm can be said unmistakably only by looking at the behavior of Medusa.

How jellyfish learns about the approach of a storm: physics

Meduses are aware of the approach of the storm

There is a structure in Medusa’s body that responds to fluctuations in the infrasound frequency, and precisely capturing these fluctuations, make the body respond accordingly. So jellyfish learn about the approach of the storm in terms of physics. Besides:

The air coming from the advancing storm gives rise to waves and on the crest of the wave there are fluctuations - infrasound, with a frequency range from 8 to 13 hertz.
It is these frequencies that the jellyfish captures.
This ability of Medusa interested scientists. The device called the "storm predictor" was invented.

Thanks to this device, it is possible to prevent serious consequences of the weather. Using the device, you can warn about the storm in 15 hours Before his appearance, while an ordinary barometer gives all 2 hours.

Are there any edible jellyfish?

For many people, this will be a surprise, but in nature there are edible jellyfish. It is worth noting that there is 25 species of jellyfishwhich you can eat without fear. They are added to marinades and salads. Their taste is salty and looks like noodles in appearance.

More than 1700 years in China eat jellyfish.
In special sea farms, they are grown up to commodity weight, which is 15 kg.
The most delicious jellyfish lives in the yellow sea.
In the eastern cuisine, female individuals have an advantage.
For different dishes, different parts of the medical trunk are used. But mainly, cooks are used in the kitchen only hats of these animals. They have more nutrients.

If you are going to cook a jellyfish, then remember the following:

For the first dishes, the whole body is suitable.
The main condition is that the jellyfish must be freshly.
For light snacks and salads, a hat and tentacles are suitable.
For hot dishes, only the bell is suitable.
Fried jellyfish has crispy taste properties, especially the head.

Possessing the taste of the fresh soft cartilage, the jellyfish goes well with the products with which it is prepared. She adopts their smells. Medusa is especially good with seasonings - sharp and spicy.

Who eats jellyfish?

Despite the relations of jellyfish to predators, they can be prey for marine inhabitants and birds. Having a transparent body with a constantly changed shape, the jellyfish is well camouflaged, it is inconspicuous. For such a creature, this is very important, since there is nowhere to hide in the water thickness.

Who else eats jellyfish? Interesting Facts:

Especially enjoyed with jellyfish loves of luna and marine reptile-leathery turtle.
Of the birds, Medus loves to eat albatrosses. But they eat only not toxic such creatures. The peculiarity of the beak of albatrosses can easily hold the slippery trophy object.
They love jellyfish and Pacific salmon, they feed on them during the breeding period.
Council - Pacific fish living from California to Japan also likes to eat such jelly -like creatures. For her, this is the main type of food.

As you can see, not only people from Asian countries, but also birds and fish love to eat Medus.

A common sign of hydra and jellyfish

Hydra has much in common with the jellyfish

Outwardly, jellyfish and hydra are not similar, but they have common signs:

All jellyfish with a dome in the form of an umbrella, at the end of the proboscis there is a mouth, like a hydra
The body is 95% of the water.
The presence of stinging cells
Lack of nervous system
Type - intestinal
Radiation symmetry of the body
Primitive digestive system

The jellyfish, like all her counterparts, two layers of cells, the outer - ectoderm and the internal endoderm. In the jellyfish, the interglastic layer is filled with a gelatinous substance. The hydra has a thin basal membrane - a plate. The second feature of organisms belonging to the intestinal is two -layer.

Actes and jellyfish: Differences

Another marine creature that is sometimes confused with a jellyfish is Actini. This is the difference between these two living organisms:

Actini:

A motionless organism attached to the seabed.
Coral polyps with a soft body, but are not able to move - this is what anxy is.
They belong to another class of polyps that are closest to jellyfish.
Another name for them is anemones. Perhaps this is because of their beauty and similarity to flowers.
The assets body consists of a cylinder -shaped leg, on the top of which a tentacle bundle flutters.
The leg is equipped with transverse and longitudinal muscles, thanks to which the assets can bend, shorten and lengthen.
From below, the leg of the acting has a pedal disk or a different sole.

Jellyfish:

Free -fluid intestinal animal.
The scheme of the structure of the jellyfish may vary depending on its lifestyle.
Free -saving individuals of this species experience a strong flattening of their body towards the main axis.
The division into polyps and jellyfish is more morphological.
One species at different stages can be a jellyfish or polyp.
In a state of jellyfish, intestinal breasts are in a single state. Polyps are rarely single.

The dimensions of jellyfish: from 2 mm to 2 m, Actinium - from 2 mm to 1.5 metersin diameter and 1min height. They live at different depths. There are deep -sea jellyfish, they have special cells that can glow. Among the largest is a jellyfish living in the Arctic latitudes - cyanei and toxic representatives of the intestinal: a cross and phrasal. Actes also live in the surf zone and at great depths.

Medusa: interesting facts, briefly for schoolchildren

In the upper layers of the seas and oceans ( 180-200 m. from the surface) lives 38.5 million tons Medus. From their poison, much more people die annually than from the attacks of sharks. The seas of Japan are filled during flowering 500 million individuals Medus, the size of a closet. Here are still interesting facts about jellyfish - briefly for schoolchildren:

Among the jellyfish there are no disabled people: their symmetrical body is able to recover after the injury.
There is a form that uses photosynthetic algae as batteries for recharging.
Medus does not have many organs. They breathe with their whole body. They eat and go to the toilet through one hole.
Under adverse climatic conditions, they can stop the development and exist in the form of a polyp.
Meduses exist more 0.5 billion years. They survived all the cataclysms on the planet, including global ones.

Medusa amazing creatures. People admire their unique appearance. Meduses have phenomenal survivability and the highest propagation ratio. These animals have great life potential. They quickly recover during injuries, retain hunting instincts and the ability to reproduce throughout life.