Sea anemones. Sea anemones, sea anemones. Lifestyle and nutrition

XI INTERNATIONAL DISTANCE OLYMPIAD “ERUDITE” ON THE SUBJECT OF THE WORLD AROUND

Sample answers to assignments for grade 4

The maximum number of points awarded for completed tasks is 100 points

Task No. 1 (max 20 points):

Look carefully at the images of living organisms located in the table below.

How do these organisms move? If the method of transportation is unknown to you, then guess it.

If any of these living organisms have different ways movement, then be sure to indicate this.

If any organisms are familiar to you, write their names.

Image of a living organism	Name of a living organism	Description of the method of transportation
	Single-celled animal "Ciliate slipper"	It moves due to the work of cilia located on the surface of the cell body. If you look closely, you can see them in this photo. It is the vibrations of the cilia located on the surface of the body of the ciliate slipper that allow it to move in space.
	Starfish	For movement sea stars ambulacral legs are used. In these echinoderms they can contract and extend to a considerable length. The star throws its legs forward and sticks them to the surface of the bottom, and then contracts them, pulling up their body. This is how it moves. The legs are driven by the pressure of water pumped into them.
	Jellyfish	It is typical for a jellyfish to “ jet propulsion", due to which it is capable of vertical movement. She takes in water and then forcefully pushes it out of the bell. Thanks to this, jellyfish move up or down, or diagonally, but they are unable to move horizontally. A jellyfish cannot move in a specific direction, so sea currents play a huge role in the movement of jellyfish.
	Cuttlefish	The cuttlefish is characterized by “reactive movement”, it draws water inside itself, and then pushes it out through a narrowed nozzle, while developing significant speed (sometimes reaching 50 km/h). For movement, cuttlefish also actively use a wave-like bending fin.
	Lobster	Lobsters usually move along the seabed using walking legs. But frightened lobsters can make large leaps in the water in the opposite direction. To do this, they quickly and powerfully rake with their tail equipped with blades. Such a jump will allow the lobster to instantly bounce away from the source of danger to a distance of up to 7 meters.
	Octopus. This animal is a cephalopod.	The octopus is characterized by “jet motion”. It can swim backwards with its tentacles, propelling itself with a kind of “water-jet propulsion” - drawing water into the cavity in which the gills are located, and forcefully pushing it out in the direction opposite to the movement, through a funnel that plays the role of a nozzle. The octopus changes the direction of movement by turning the funnel. An octopus can move on a hard surface by crawling, using tentacles with suction cups.
	sea anemone	Adult sea anemones lead a sedentary lifestyle. The motile ones of sea anemones are the “dispersal larvae” (it is they that are capable of actively swimming and performing a dispersal function). Sometimes sea anemones enter into symbiotic relationships, for example, with hermit crabs. And then they have the opportunity to move in space at the expense of their partner - the symbiont. Sea anemones living on soft substrates cannot attach to the ground, so they can, if necessary, move slowly along the substrate. In this case, part of the fleshy sole is torn off the ground, pushed forward and secured there, and then the rest of the sole is pulled up.
	Freshwater hydra. This animal belongs to the coelenterate animals.	Freshwater hydra is capable of “walking.” To do this, the hydra bends in the desired direction until its tentacles touch the substrate on which it sits. Then, literally, it stands on the “head” (that is, on the tentacles), and the sole, the opposite end of the body, is now on top. After which the hydra again begins to bend its body in the desired direction. The hydra moves in the desired direction as if tumbling. As a rule, hydra leads a sedentary lifestyle. It is also possible for the sole to slide very slowly over the mucus secreted by the cells of the sole.
	Leech. This animal belongs to the annelids.	The leech has three ways of moving in space: 1. Moving using “walking movements”. The leech has two suckers. First, it extends its body forward and attaches itself to an underwater object with a front suction cup. Then it releases the rear sucker and pulls its body towards the front end (front sucker). 2. The leech can also swim slowly, making wave-like movements with its entire body thanks to its well-developed muscles. 3. Very often a leech, Having attached itself to a fish or animal living in the water, it moves with the help of its “master”.
	Scallop	The scallop is characterized by “reactive movement”; they move as if by jumping. The valves of scallop shells first open sharply and then abruptly close. As a result of this, water is forcefully pushed out of the “mantle cavity” in two powerful jets. It is these powerful jets that push the mollusk’s body forward. Large sea combs are capable of jumping up to 50 cm.

Z Task No. 2 (max 20 points):

You, like all Russian children, are probably very familiar with this cartoon character - a hedgehog lost in the fog. Most likely, you have seen a real, live hedgehog more than once in your life. But is it as familiar to you as it seems at first glance?

Answers on questions:

What reserves does a hedgehog make for the winter?

The hedgehog does not store supplies for the winter, since in winter it hibernates.

Where does he hide them?

AND

Rice. No. 1: Hedgehog in the fog.

going from the question to the first question “Nowhere”.

What does a hedgehog eat during the long, long winter?

Sleeping. It is in a state of hibernation.

Additional explanation:

Common hedgehogs They do not store food for the winter - neither apples, nor mushrooms, nor anything like that, since they are insectivorous animals.

In winter, the hedgehog hibernates. And during hibernation, the hedgehog uses its fat reserves accumulated in summer/autumn.

Task No. 3 (max 20 points):

Answers to biological riddles:

Who has more legs: five octopuses or four squids?

Same number of legs.

Octopuses have 8 legs, i.e. 8*5=40,

Squids have 10 legs, i.e. 4*10=40

Therefore, the same number of legs, i.e. 40 legs each.

This animal has two right legs and two left legs, two legs in front and the same number in back. How many legs does this animal have?

Four

Which berries with the letter “M” are sweet, and those with the letter “K” are bitter?

"M" - raspberry

"K" - viburnum

What kind of grain can grow... on a person?

Stye on the eye

The waist of which animal is the standard example of a thin waist for all women?

Wasp waist (wasp waist)

The name of which bird is heard all the time in the scaffolding?

Myna is a pink starling and the construction team "put it down!"

The "economic breed" of dogs is

Breed Dachshund (dachshund is a clearly established level of tariffs, prices, payment).

Whose eyes are not afraid, but love to look at the sun?

Pansy (decorative flower).

Name the climbing animals.

Geckos (reptiles)

Which waterfowl wrote famous books?

Gogol

Task No. 4 (max 10 points):

Remember what you know about the structure of the human body.

Please take a close look at the table below.

Distribute the organs of the human body into their corresponding organ systems, using numbers and letters.

You can simply write the letters representing the organs in the column with organ systems.

Task No. 5 (max 20 points):

Take a close look at the matrix below and its hints.

Fill out the matrix by entering the missing letters in the names of the animals.

Please note that the names of all these animals end in -KA.

Find out how well you know animals?

And

With

Hints for the task.

An animal that looks like a mouse, but with a muzzle elongated into a proboscis.

One of the varieties of bats with very wide ears.

A shrew with the tops of its teeth colored brown-red.

A rodent that lives in steppes and deserts with a very short tail.

A small red rodent, very similar to a rat, but with a tufted tail, living in the desert.

Little monkey.

Harvest mouse.

A small rodent, similar to both a mouse and a jerboa, its tail is much longer than its body.

The largest of the toothed whales.

Barking pet.

Meowing pet.

Cute furry animal.

Artificially bred fur-bearing animal.

A small predatory animal.

Task No. 6 (max 10 points):

Try to guess old, Russian, folk riddles.

Sea anemones - coral polyps large size, which, unlike other corals, have a soft body. Sea anemones belong to a separate class of coral polyps, and they are also related to jellyfish. They are also called sea anemones because they have such a beautiful appearance that they look like flowers.

Features of the appearance of sea anemones

The body consists of a cylindrical leg and a bunch of tentacles. The leg consists of circular and longitudinal muscles, thanks to which the sea anemone can stretch, shorten and bend. At the bottom of the leg there is a sole or pedal disc.

Mucus is released from the sea anemone's leg, which hardens, and the sea anemone sticks to the substrate. Other sea anemones have wide legs, with their help they cling, like an anchor, to loose soil, and the sole with a bladder acts as a fin. These types of sea anemones swim upside down.

At the upper end of the body is an oral disc, which surrounds a row or rows of tentacles. In one row the tentacles are the same, but in different rows they may differ in color and size. The tentacles are equipped with stinging cells, from which thin poisonous threads fly out. The mouth opening may be oval or round in shape.

Sea anemones are fairly primitive creatures that do not have complex sensory organs. The anemone's unequal system consists of a group of sensory cells located on the sole, base of the tentacles and around the mouth opening. These nerve cells respond to various stimuli, for example, cells near the mouth are able to distinguish substances, but do not respond to mechanical influence, and cells on the sole do not respond to chemical exposure, but are mechanically sensitive.

Most sea anemones have a naked body, but sea trumpet anemones have a chitinous cover, their leg looks like a tube, which is why they are called “tubular”. The bodies of some sea anemones are covered with grains of sand and various building material, which make the cover more durable.

The color is so diverse that even representatives of the same species can have different shades. Sea anemones can be all the colors of the rainbow: pink, red, green, orange, white and the like. Often the edges of the tentacles have a contrasting color. The body sizes of anemones vary over a wide range.

The body height of the smallest one, gonactinia, is 2-3 mm, the largest is the carpet anemone, with a diameter of up to 1.5 meters, and the height of the metridium sea anemone reaches 1 meter.

Distribution and habitats of sea anemones

Sea anemones live in all oceans and seas. Most of these animals are concentrated in subtropical and tropical zones, but they are also found in the polar regions. For example, in the seas of the North Arctic Ocean lives the sea pink or metridium senile.

The habitats are quite diverse: from the depths of the ocean to the surf zone. Few species of sea anemones live at ocean depths of more than 1000 meters. Although sea anemones are mostly marine animals, certain species can live in fresh water. There are 4 species of sea anemones in the Black Sea, one species lives in the Sea of Azov.

Anemone lifestyle

Anemones that live in shallow water often have microscopic algae in their tentacles, which gives them a green tint and supplies them with nutrients. These sea anemones live in illuminated places and are active mainly during the day, as they depend on the photosynthesis of algae. And certain species cannot tolerate light at all. Sea anemones that live in the tidal zone have a clear diurnal regime, which is associated with the time of drying and flooding of the territory.

All sea anemones can be divided into 3 types according to their lifestyle: swimming, sessile and burrowing. Most sea anemones are sessile, the burrowing ones include the genera Haloclava, Edwardsia and Peachia, and only the genus Minyas is swimming.

Sea anemones are attached to the bottom using the so-called “sole”.

Sedentary sea anemones, contrary to their name, are capable of moving slowly. As a rule, they begin to move if something does not suit them, for example, lighting or lack of food. Sea anemones move in several ways. Some species arch their body and attach themselves to the ground with their oral disc, then tear off their leg and move it to a new place. Sessile jellyfish move in a similar way. Other species move their sole, alternately tearing off sections of it from the ground. And the third way is that sea anemones lie on their sides and crawl like worms, while different parts of the leg contract.

In fact, burrowing sea anemones do not burrow that often. They sit most of their lives, and they are called burrowers because they can burrow into the ground, and only the corolla of the tentacle remains visible from the outside. In order to dig a hole, the sea anemone acts in a rather interesting way: it takes water into the oral cavity, and alternately pumps it to one end of the body, and then to the other, so it goes deeper, like a worm, into the ground.

Sessile small gonactinia is sometimes capable of swimming; during swimming, it rhythmically moves its tentacles, its movements are similar to contraction of the dome. Floating species float passively on the water with the help of pneumocystis, and move with the help of the current.

Relationships between sea anemones and other marine inhabitants

Sea anemones lead a solitary lifestyle, but if conditions are favorable, then these polyps unite in colonies, forming beautiful flowering gardens. Basically, sea anemones do not show interest in their relatives, but some of them have a quarrelsome disposition. When these anemones touch a relative, they attack it with stinging cells, which cause tissue necrosis.

But sea anemones often get along well with other species of animals. The most striking example of symbiosis is the life of sea anemones and clown fish. The fish take care of the polyps, clearing them of food debris and various debris, and the sea anemones eat the remains of the clown fish’s prey. And shrimp often find shelter from enemies and food in the tentacles of sea anemones.

Sea anemones - beneficial organisms. They live in tropical and subtropical waters.

The relationship between adamsia sea anemones and hermit crabs is even better established. Only young Adamsia live independently, and then hermit crabs find them and attach them to their shells. In this case, the sea anemone is attached with its oral disc forward, thanks to which it gets food particles from the soil churned up by cancer. And sea anemone protects crayfish from enemies. Moreover, when a crayfish changes its home, it transfers the sea anemone to a new shell. If the cancer has not found its sea anemone, it tries to take it away from its fellow.

Feeding sea anemones

Some sea anemones send everything that touches their tentacles into the oral cavity, even pebbles and other inedible objects, while others spit out what cannot be eaten.

Polyps feed on various animal foods. Some species filter water and extract organic debris from it, while others hunt larger prey - small fish. For the most part, sea anemones feed on algae.

Anemone reproduction

Reproduction in sea anemones can occur sexually and asexually. Asexual reproduction occurs due to longitudinal division, in this case two individuals are produced from one individual. This method of reproduction is found in the most primitive sea anemones, gonactinia. A mouth is formed in the middle of the leg of these sea anemones, after which the animal splits into two independent organisms. Since sea anemones are capable of asexual reproduction, they have a high ability to regenerate tissue: sea anemones quickly restore lost body parts.

Most sea anemones are dioecious. But there are no differences between male and female sea anemones. In certain species of sea anemones, both female and male reproductive cells can simultaneously form.

The process of fertilization in sea anemones can occur in the gastric cavity or in the external environment.

In the first week of life, anemone larvae move freely in the water, due to which they are carried over long distances by the current. In some species, larvae develop in special pockets that are located on the bodies of the mother.

Any person who has seen this amazing creature is primarily interested in: is sea anemone an animal or a plant? Many are misled by the definition of this creature - “sea anemone”: nevertheless, most people know that an anemone is a flower. The amazingly beautiful ones that have managed to adapt to life in the form of rather vulnerable organisms amaze the imagination: you just want to take them with you, protect and shelter them. Not worth it! First of all, it’s not for nothing that these creatures are sometimes called “jellyfish-anemones”: they are quite capable of standing up, and not only for themselves. And secondly, you are unlikely to be able to create suitable living conditions for them. So, while at the resort, just enjoy the view of them and try not to swim too close, so as not to treat the rather painful burns after.

Appearance

It is the appearance of these creatures that gives rise to the eternal question: is sea anemone an animal or a plant? And by the way, until the end of the 19th century they were classified as plant species. However, science does not stand still: it has been established that “sea anemones” are animals that, in their structure and lifestyle, are close to jellyfish and other coelenterates, to which many biologists include ctenophores.

If we explain it in a primitive way, then any sea anemone (photos are presented) is one continuous mouth on a stalk. The flower-like “petals” are the tentacles responsible for delivering food. Most often, the “stand” has a flat sole, with which the “sea anemones” are attached to a rock or hard bottom; but there are species with a pointed limb - they are stuck into the bottom like a bouquet; And there are floating varieties. Observing the behavior of these creatures, you will no longer be puzzled: is sea anemone an animal or a plant? It immediately becomes clear that she is not just an animal - she is a predator.

Sea anemones are not polyps

It would also be a mistake to say that this most beautiful creature is coral. The sea anemone is, without a doubt, very close to the polyps that form the islands that captivate everyone. However, they do not form a skeleton, and corals are the skeletons of polyps. At the same time, it cannot be said that sea anemone is “soft-bodied”, since the substance that fills the space between its cells forms a very thick layer and is similar in density to cartilage in vertebrates.

What do they eat?

Another argument in doubt is whether sea anemone is an animal or plant - its diet. If those interested remember, plants feed on water (with substances dissolved in it) and what they can get from the soil. However, sea anemones prefer a completely different menu. It includes small invertebrates and small fish (if you're lucky). The method of obtaining food is also completely non-vegetative: the tentacles paralyze the prey and pull it towards the mouth. Some may object: this is also known, but they cannot boast of a mouth and dissolve prey with enzymes located directly on the leaf plate or in a trap flower. That is, they do not have organs intended exclusively for digestion.

Impact on the victim

Even if we assume that sea anemone is a plant, then we must look for an explanation for its hunting method. In each stinging cell - albeit very, very small - there is a kind of capsule containing poison. And on the outside there is a stinging thread with spines facing backwards. Visually, under a microscope, this entire device resembles a miniature harpoon. When an anemone attacks, the thread straightens, the needle pierces the victim’s body and releases poison. Not a single plant has such a complex structure - they are much lower on the evolutionary ladder and have a much simpler structure.

By the way, the stinging venom of sea anemones is dangerous even for such a large organism as a person. Of course, it will not lead to death, but it will cause a burning sensation with itching, and in some cases, necrosis will develop. Almost all of those who regularly interact with gentle “anemones” have allergies.

Famous symbiosis

It must be said that most sea flowers lead a sedentary lifestyle. However, updating the hunting grounds is what any sea anemone needs. Movement is usually accomplished through symbionts. The most famous of them (familiar thanks to the touching Soviet cartoon) is the hermit crab. The most interesting thing is that this shellfish itself transfers to its “shell” a creature that is deadly for mollusks. Enough for a long time they coexist peacefully: the crayfish carries the sea flower from place to place, the sea anemone repels the attacks made against it by its natural enemies. However, everything is not so rosy: the “leg” of the sea “flower” easily dissolves the organic matter that makes up the host’s shell, after which the cancer comes to an end.

Moving sea anemones

Even those sea anemones that are designed by nature to “sit” in place can move. In the end, the small inhabitants of the oceans, as people say, are “no dumber than a steam locomotive” and over time they realize the danger of some bottom area. Accordingly, ocean flowers are forced to migrate as their hunting grounds become scarce. What does the average sea anemone do in this case? She moves slowly but surely. The sole is separated from the bottom, extended a short distance, secured and tightens the rest of the body. However, small species (like gonactinia) can even swim, straightening their tentacles back.

Fish-anemone cooperation

It must be said that ocean anemones symbiote not only with hermit crabs. They also travel on other armored animals (however, for carriers this usually ends the same way, even in the case of small varieties). However, sea anemones can coexist quite peacefully with fish. Off the Australian coast, the largest sea anemones on earth (their “mouth” is often not limited to one and a half meters in diameter) provide shelter among their tentacles for amphiprions - very bright fish that feed the “host” with fallen food debris, and with the work of their fins they create additional aeration for it. At the same time, anemones are quite capable of distinguishing their friends from other fish and actively protect them from predatory attacks.

Reproduction of sea anemones

They give preference to the sexual method, which is another proof that sea flowers are animals, not plants. However, in unfavorable conditions they can use budding, in which you begin to remember the misconception about “anemone is a plant,” and longitudinal or transverse division. This is especially true for small varieties. The same gonactinia tends to split across. It is extremely interesting to observe: first of all, a wreath of tentacles grows around the circumference of the body, and then it divides. The upper half grows a sole, the lower half grows a “mouth” and another set of goads. It is noteworthy that the second division does not wait until the end of the first, so that the sea anemone of this species can be surrounded by several rings of tentacles, foreshadowing the imminent appearance of several individuals.

You can check whether an anemone is an animal or a plant by your own example. Sea anemones do not regard humans as either an enemy or prey. So, when touched by a person, they simply curl up (if you don’t fiddle with them, of course). You could say they are hiding. Otherwise, the sea anemone (the photos demonstrate this) is a very beautiful and interesting creature, which is interesting even just to watch.

Sea anemones are common in the coastal waters of all seas of the world. Most of these animals, varied in shape and color, live on the coral reefs of the tropical zone.

   Type - Coelenterates
   Class - Hydroid
   Family - Actiniaria

Basic data:
DIMENSIONS
Length: from a few centimeters to a meter and even more in diameter.

REPRODUCTION
Asexual: division or budding.
Sexual: by releasing eggs and sperm into the water where free-swimming larvae develop or by internal fertilization.

LIFESTYLE
Habits: Some individuals lead a sedentary lifestyle on the seabed or other solid base.
Food: depending on the species, from plankton to medium-sized fish.

RELATED SPECIES
Sea anemones, together with corals, belong to the hydroid class, which unites about 6,500 species.

Brightly colored sea anemones with thin tentacles are one of the most beautiful marine inhabitants. For careless fish and other small sea animals that, through their carelessness, ended up very close, the embrace of the sea anemone’s burning tentacles means inevitable death.

FOOD

Sea anemones do not feed on plant or animal food. They capture food using tentacles. Small species reveal tentacles that are overgrown with small hairs. The movement of water caused by the influx brings microorganisms into the mouth.
Large species grab fish and crustaceans, which they kill with the poison of miserable cells. Sea anemone has peculiar organs. The muscular pharynx leads from the oral opening to the gastric cavity. When food enters it, digestive juice begins to secrete from the openings of the glands. After nutrients get into the tissue.

DESCRIPTION OF ANEMONE

Sea anemones are a group of soft-bodied animals that are associated with polyps. Sea anemones and corals belong to the class of coral polyps. Like all other coelenterates, they have a very simple body structure. It is based on one outer and one inner layer of cells. The inner layer, or endoderm, limits the gastric cavity of the body, which has one opening. Through it, the sea anemone receives food and excretes waste.
The outer layer, or ectoderm, consists of large quantity thin tentacles that grow around the mouth opening located at the top of the body. The tentacles have a myriad of tiny cells that serve to protect themselves and capture prey. Sea anemones have limited mobility, so they spend their entire lives attached to the seabed, rocks and coral. The disc on the underside of the anemone's sole secretes a sticky substance (the so-called cement), which allows it to stay on the rocks despite sea currents, ebbs and flows. Anemones cannot walk, but with the help of muscle contractions they can move their tentacles.

REPRODUCTION

Sea anemones can reproduce in several ways. They rarely reproduce by budding. More often, sea anemones are divided into several parts. In other species, part of the sole is separated, from which a new sea anemone grows. Some reproduce sexually. There are individuals that, being hermaphrodites, secrete both eggs and sperm. Other species are dioecious. Eggs and sperm are released in huge quantities into the water, where fertilization occurs.
In this case, larvae hatch from fertilized eggs, which then settle to the bottom and develop to the size of adult organisms.

FEATURES OF THE DEVICE

Sea anemones are one of the best examples animal symbiosis, which brings mutual benefit to two organisms, which often belong to different systematic types. Sea anemones are armed with stinging cells that can spray paralyzing poison. Some types of sea anemones often stick to the shell of a hermit crab. The hermit crab, with the help of sea anemones, protects itself from enemies who are scared away by the burning tentacles of the sea anemone, and it, in turn, feeds on the remains of its food. Numerous species of small coral fish live among the tentacles of sea anemones. The most famous of them is the clown fish. These fish protect their bodies from the pathetic tentacles of sea anemones with a layer of mucus. The coexistence of clownfish and sea anemones benefits both sides: the sea anemones provide the fish with reliable shelter, and in exchange they feed very brave hunters.

DID YOU KNOW THAT...

Some sea anemones dig holes in bottom sandy sediments or in sand, and there they wait for prey.
Sea anemones of the genus Tealia are difficult to notice. They are perfectly camouflaged, covering themselves with sand and fragments of shells.
Sea anemones are not always small. Species living off the coast of Australia can be more than a meter in diameter.
From an evolutionary point of view, sea anemones are very primitive. They do not have a brain, and the nerve fibers make up a network of sea anemones that connect the sense organs directly to the muscles.
The scientific name of some sea anemones - Anemonia - comes from the name of the anemone flower.

WATCHING ANEMONE

On the coast of the Baltic and North Seas There are several species of sea anemones. Very common are sea anemones of the genus Tealia, small green or brown sea anemones that live in the tidal zone. At high tide you can see their tentacles open. The largest sea anemones are found only at great depths. It has many delicate pink or white tentacles. In the Black Sea, you can mainly see the reddish-brown or greenish horse anemone (Actinia equina), which is attached to the stones.

CHARACTERISTIC FEATURES OF ANEMONES

   Sole: the underside of the body secretes a cement-like substance with which sea anemones attach to the soil.
   Tentacles: they grab prey and bring it to the mouth; have stinging cells.
   Mouth opening: contains microscopic hairs. Thanks to them, water circulates around the body.
   Slime: needed to catch prey.

PLACES OF ACCOMMODATION
Sea anemones live in almost all seas of the world, most often in tropical waters.
PRESERVATION
The sea anemone Nematostella vectensis, which lives in a salty environment, is rare in Europe today due to drainage and pollution of waters. Some tropical species are at risk of extinction due to the destruction of coral reefs.

Sea anemones are unusual in beauty and quite mysterious in their way of life. But where do sea anemones live? What are their appearance? Now we'll find out...

Scientists have long argued about what type of animal these creatures belong to, because they have something in common with both corals and jellyfish, and in appearance sea anemones generally look like underwater plants.

The modern classification classifies coral polyps specifically; moreover, these living organisms are among the most major representatives corals

Another name for sea anemones is sea anemones; the animals received this name precisely because of their resemblance to flowers.

The structure of the sea anemone is a body consisting of a corolla of tentacles and a cylindrical leg. At the base of the leg there are muscles (longitudinal and circular). The end of the leg may have a so-called sole.

Anemones are bottom-dwelling plants, so they need to gain a foothold on the surface of the ground; they do this with the help of various devices.

Some representatives of this type of coral secrete a special mucus, which tends to harden over time and thus firmly anchors the animal’s body to the substrate. Other sea anemones have such a large and strong leg that they are able to bury it in the ground and in this way securely attach themselves to the underwater soil.

But among sea anemones there are also exceptions that do not live on the bottom of the sea, but freely float in the water column. They are also called floats. In the sole of such species there is a special bubble that prevents the animal from sinking to the bottom and constantly maintains it in a floating state.

The upper part of the sea anemone's leg has a mouth opening, represented by a disk surrounded by many tentacles, which are arranged in rows.

These same tentacles are equipped with stinging cells that can shoot a thin thread containing a poisonous secretion. If you look at the sea anemone's body, you will notice pronounced radial symmetry.

As for the various sensory organs inherent in most living organisms, sea anemones in this sense can be called one of the most primitive.

Nervous system of these animals consists of sensory cells located at the base of the tentacles, around the oral disc, and also on the sole.

The main distinguishing feature of these sea creatures, undoubtedly, is their color. It is not for nothing that they are called sea flowers, because their colors contain the brightest tones: pink, orange, red, white, brown, green, yellow and others. In some species, you can find a whole rainbow palette on the body, since the body has one color, and the tentacles are painted in a contrasting shade.

The size of sea anemones is also surprising: the smallest representatives of this group of animals can have a millimeter height, and there are also giants whose “height” reaches one meter.

The smallest sea anemone discovered by scientists is considered to be the Gonactinia prolifera sea anemone; its height is only 2 millimeters.

These animals are widespread in all oceans and seas; the greatest species diversity is manifested in the tropical and subtropical zones. Sea anemones have acclimatized even in the icy waters of the Arctic Ocean.

According to their feeding method, sea anemones are predators. Some species swallow everything into themselves (both stones and paper), others, after accidentally swallowing an extra object, spit out the unnecessary.