Sea anemone (sea anemone): what is it and what does the predatory animal look like

Sea anemones (or anemones) are sedentary animals. They all live independently in the water column. Most often they are attached to the ground, on which they can move, using a “sole”. They are common in almost all, mainly warm, seas of the world, at different depths.

They adapt well to their environment - some species tolerate waters with lower salinity - they are found in estuaries. Next, we’ll tell you more about the conditions of detention, how to properly feed sea anemones and symbiotic relationships with other fish!

Description of sea anemone

Many aquarists, upon hearing the name sea anemone, begin to doubt whether it is a plant or an animal. To answer the question, you need to study the structure of the underwater inhabitant.

Animal or plant

Sea anemone is a predatory animal. The sea anemone's body is quite interesting. The tentacles, similar to flower petals, are responsible for delivering food. Some types of anemones have a flat sole, with the help of which they are attached to the bottom, other varieties have a pointed limb, with its help they stick into the surface, like a bouquet of flowers, while others swim and move.

Biological features

Their cylindrical body usually reaches several centimeters in diameter, but in some cases it can reach 1.5 meters. The bright colors are carotene dyes. The tendons, usually single, extremely branched, may be corolla-shaped at the edge of the slit mouth or, if numerous, in functionally diverse whorls covering the entire flat oral shield.

Type, class and squad

Many aquatic enthusiasts wonder: is sea anemone a plant or an animal? The answer is simple, “Sea flowers” ​​refer to coral polyps, a class of marine invertebrates from the type of anemones. More than 1,400 species have been studied; they are divided into 46 families, grouped into suborders:

• Endocoelantheae
• Nyantheae,
• Protantheae,
• Ptychodacteae.

Habitat

Sea anemones grow on rocks and seashores at all latitudes of the globe and at different depths. The largest number of species live in the coastal zone of warm seas, some may inhabit waters with lower salinity.

Internal structure

Sea anemones do not form an internal skeleton. The nervous system consists of an external and internal network with special innervation of the antennae and oral plate. They have well developed muscles. Numerous and varied stinging cells (haplonemas, heteronemes and spirocysts) are used for defense and hunting. Anemones are predators - they crush prey with their stings and draw their antennae into their mouths or push plankton towards them with the movements of their cilia.

External features

The only morphological form found in anemones is a single polyp 1.5-10 cm high and 1-150 cm in diameter. Polyps of most species are characterized by an elongated cylindrical shape and a bright, often multi-colored color. In the trunk of the polyp there are cinclids (ostia) - lateral openings that serve to remove water from the absorbing-digesting cavity, as well as various types of lateral processes.

The open mouth leads to the throat, which has two grooves (siphonoglyphs), the function of which is to supply water to the absorbent and digestive cavity.

The digestive cavity (gastrovascular cavity) is surrounded by two layers of cells:

1. outer layer (ectoderm),
2. inner layer (endoderm),

between which there is a thin layer of jelly-like mesoglia. The ectoderm contains highly developed epithelial muscle cells, which in some species (Metridium) form the sphincter. In the absorbent-digestive cavity there are numerous vertical partitions, which may be based on long-lasting aconations (stinging threads) that perform protective functions. These appendages contain nematodes and glandular cells that produce digestive enzymes.

Nutrition

Anemones are predatory animals; they feed on animal plankton, crustaceans (shrimp, crabs), mollusks and small fish. They subdue prey with their stingers and then pull it towards their mouth.

Reproduction

Coelenterate sea anemones reproduce sexually or asexually. They are mostly dioecious or bisexual. Parthenogenesis is rare - this is how, for example, the horse anemone (Actiniaequina) reproduces. Sexual reproduction by external or internal fertilization. Like all corals, anemones do not have a jellyfish stage. There are several larval stages in development:

• planula,
• Edwardsia,
• chalkampula.

Asexual reproduction occurs through longitudinal fission, transverse fission, rupture or budding. Some species take care of their offspring - their young remain on the mother's body for some time.

Interaction with other organisms

Anemones form symbiotic relationships with various species of invertebrates and fish. Species from the genera Adamsia, Calliactis and Neoaiptasia live attached to the shells of hermit crabs (Paguroidea), where in exchange for protection from predators they gain the ability to move and forage efficiently. Anemones belonging to the genus Stoichactis live in symbiosis with clownfish (Amphirion), protecting each other from attacks by predators.

Common types

Various types of sea anemones can be found in their natural habitat. There are approximately 1,500 known species of invertebrate animals. If we compare with jellyfish living in freshwater bodies, there are no such sea anemones.

Sea anemone

Horse anemone (lat. Actinia equina) is the most common species. In nature, it inhabits the White, Azov and Black Seas. Likes to live along the coastline and hide under rocks. Prefers salt water. It reproduces well at home.

Horse anemones are ideal candidates for a reef aquarium.

Blister sea anemones

Bladder anemone or enktakmeya quadricolor is the easiest animal to keep in artificial conditions. Anemones can be colored pink, green, or brown. The pink bubble anemone has colorless bubbles at the end of its tentacles. But in order to observe their formation, it is necessary to install bright lighting in the aquarium. If there is a deficiency of light, there will be no bubbles, and the tentacles will stretch out and lose their appearance.

Bladder anemone - the most recognizable among its family

Carpet sea anemones

The green stichodactyla haddoni has a translucent body and can be yellow, light green or white. The upper body expands significantly. The mouth and tentacles are purple, yellow or pink.

Due to the fact that the tentacles contain a toxic substance, which animals throw out in case of danger, it is advisable to keep the anemone in a spacious tank. In this case, they will not be able to harm other underwater inhabitants. Good neighbors are clown fish.

The giant carpet anemone is the largest of all its relatives. The corpus spongiosum is disc-shaped. Wide range of colors: colors can be green, blue, purple, pink. There are folds around the oral disc. Under artificial conditions, the body size is 50 cm.

This type of sea anemone is one of the most difficult to keep in an aquarium.

Red-bodied sea anemone

Red or orange is the main color of the red-bodied sea anemone. The tone of the tentacles can be red, purple, green, yellow, blue. The length of the tentacles reaches 20 cm, the body – 30 cm.

Attention! To breed one representative, an aquarium with a capacity of 200 liters is required.

The incredibly beautiful red-bodied sea anemone adapts quite well in a marine aquarium

Range and habitats

Tropical latitudes are the favorite habitat of sea anemones. Some species can live in cool water. For example, the sea pink or metridium chose a place to live - the Arctic Ocean.

In the waters of the Azov Sea you can find 1 species, in the Black Sea - 4 species. Some inhabitants like to settle in the coastal zone, others prefer the depths. Even 1,000 m is not a barrier for them; sea anemones have adapted to life in such conditions.

Polyps that live in shallow water have microscopic algae in their tentacles, so they prefer a diurnal lifestyle.

Buying Tips

If you want to keep a sea anemone as a pet, it is very important to get the right species and make sure it is healthy. There are about 1,100 species of anemones, but very few of them can adapt to the aquarium or, more simply, to the conditions of their detention.

The choice of species will also depend on the size of the aquarium. For example: Epicystiscrucifer and Bartholomeaannulata are among the easiest species to keep as they grow a maximum of 20 cm and can be kept in a 100 liter tank, while Entacmaeaquadricolor and Macrodactyladoreensis can grow up to 40 cm and therefore require a tank of not more than less than 300 liters.

This article has come to an end, you can talk about your experience of keeping “sea flowers”, this will definitely help beginners in breeding these animals.

Lifestyle and nutrition

The sea anemone's diet includes organic food. The process of food absorption in different species occurs in a special way:

1. Some invertebrate animals swallow everything that floats next to them; even debris with small stones gets into their stomachs.
2. Predatory individuals with large bodies feed on small fish.
3. Some sea anemones inspect what they have eaten and spit out everything inedible.
4. There are anemones that interact and coexist with algae and feed on them.

On a note! If marine invertebrates feel hungry, they open their tentacles wide and catch everything that is near them at that moment. As soon as the sea anemones are full, they roll their tentacles into a ball.

Among all polyps, burrowing, floating and sessile anemones are distinguished. The name “sessile” is conditional, since they do not completely sit in one place and are able to move slowly in search of food. Anemones also look for another place in case of insufficient lighting. They move using tentacles, oral disc and intestines in several ways:

• crawling from one place to another using muscle contraction;
• stepping over: first they tear off one part of the sole from the ground, then the other;
• tumbling, that is, first the anemone sticks its mouth to the surface and throws its legs to another place.

In burrowing anemones, the entire body is under the ground, only the corolla sticks out from above. To burrow into the soil, the sea anemone draws water into the gastric cavity and releases it into the ground. This is how we dive deeper. Sea anemones that can swim are held in the current by tentacles or pneumocysts.

When hungry, the sea anemone shoots out its tentacles in search of new prey.

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.

Thanks to their long tentacles, sea anemones capture food.

Reproduction methods

Anemones reproduce in 2 ways - sexual and asexual. Basically, sea anemones are dioecious polyps. However, there are no significant differences in appearance between females and males. Certain types of sea anemones can simultaneously form both male and female reproductive cells. Fertilization can occur in the environment or in a cavity like the stomach.

The emerging larvae move easily in the water column in the first days of their life. The current picks them up and carries them far from their place of birth. Some females of certain species have pouches located on their bodies. Larvae develop in them.

During the process of asexual reproduction, the cells of one individual divide longitudinally, resulting in two sea anemones. This is how gonactinia, primitive anemones, reproduce. After a new mouth is formed, located in the middle of the leg, the anemone splits into 2 parts and independent organisms are formed. Due to the fact that marine inhabitants are able to reproduce asexually, they have highly developed tissue regeneration. With the help of this feature, sea anemones quickly restore damaged parts of the body.

Interaction with other organisms

Anemones prefer solitude, but under favorable conditions, invertebrates unite in colonies, forming colorful flowering gardens.

Some anemones have an obstinate character, so when approaching other species, they attack them with stinging cells, which deadens the tissue for some time.

Colonial sea anemones coexist with clown fish. The latter swim up to the anemones and clean their tentacles of any debris, and the sea anemones eat the trophies found by the clown fish.

Hermit crabs have an excellent relationship with Adamsia sea anemones. Only young individuals live separately, and when the anemones grow up, they are picked up by hermit crabs and placed on their shells. Anemones attach to the crayfish's house with their mouth and position themselves in the direction of movement, thanks to which they eat all the particles of food raised from the ground that the crayfish stirred up. In turn, the sea anemone thanks its friend and protects him from enemies. When crayfish change their home, they move the anemone to a new one. If they didn’t have time to pick it up, then the crayfish take it away from the kidnapper.

Keeping in an aquarium

At home, you can keep carpet, horse and strawberry specimens.

Aquarium parameters

To keep one anemone, for example, a bubble anemone, you will need a tank with a volume of 250 liters. Several stones should be placed at the bottom, caves and grottoes should be installed. After some time, the anemone will choose a place for itself and thoroughly establish itself.

The location of the filter in the container should be protected so that the sea anemone does not move close and damage its tentacles. In addition, you cannot add aggressive fish to her aquarium to prevent attacks from predators.

Important! You can keep them with clown fish – pink or Maldivian.

Water quality

Only after certain water parameters have been established in the aquarium can the sea anemone be introduced:

• temperature – +22-26°C;
• salinity – 1.020 +/- 0.005;
• acidity – 8.1-8.4 pH.

It is necessary to organize good filtration with an average water supply.

Although sea anemones are considered quite strong animals, they are not so easy to keep.

How to accustom an anemone to an aquarium

The sea anemone should be introduced into the aquarium first. When the sea creature chooses a place for itself, you can move in neighbors.

Reasons for the movement of sea anemones

Invertebrate animals will move around the aquarium until they find a suitable place for themselves. While moving, the anemone may collide with corals or other invertebrates and release its stinging threads. If the filter does not have guards, sea anemone can easily get into the intake.

Discoloration of sea anemones

Loss of color can be due to several factors. The most common reasons are poor water quality and improper lighting:

• high level of illumination;
• lack of light in the aquarium;
• the water is full of nutrients;
• insufficient content of useful elements in water.

After all parameters have been adjusted, body color will be restored.

Possible problems

Sea anemones, like any other animal, can experience illness and health complications. It is very important for the owner to take care to cure the animal at an earlier stage. If you observe loss of color, lack of activity, shriveled tentacles, loss of appetite, etc., then these could be signs of serious health problems.

In addition to this, if you are feeding medications to other fish in the aquarium, remember not to allow copper-based medications into the aquarium as they may be eaten by anemones, which may be poisonous to them.

Bleaching

The anemone's color is determined by the presence of zooxanthellae, a photosynthetic dinflagellate that lives in its tissue and is often brownish in color, and some pigmentation that the anemone uses to protect its tissue from the harmful effects of the sun (something like sunscreen). These pigments often act as "dyes".

What we get in our aquariums often depends on the strength of the light and the presence (or absence) of increased nutrients. Anemone bleaching can be due to either low light levels (thus more zooxanthellae) or higher-than-necessary light levels combined with excess nutrients.

Downsizing

One of the reasons for the “drying out” of anemones is hunger. Examples of this disease are shortened tentacles, discoloration, and a decrease in the diameter of the "leg".

Active movement

The movement of sea anemones is a sign that they are unhappy with the light or water conditions in a certain part of the aquarium. To avoid this, you need to maintain salinity at 1.026, closely monitor ammonia and nitrate levels and change the water if necessary.

Important! Make sure your ammonia level is 0 and nitrate levels are 10 or less.

Interesting Facts

Sea anemones are interesting invertebrate animals that are a pleasure to observe.

1. Sea anemones do not have a skeleton; they lead a predominantly sedentary lifestyle, attaching themselves to sea soil or corals. There are also swimming species.
2. The body of all anemones looks like a cylinder. The smallest sea anemone is 3 mm, the largest is 1.5 m.
3. If undigested food accumulates in the body of an invertebrate animal, the sea anemone spits it out through the mouth.
4. After the invertebrate polyps find a suitable place for themselves, they attach to it using the sole. In the opposite direction is the oral disc, surrounded by tentacles.
5. The color of the polyps is often similar to that of starfish. In addition to red anemones, there are yellow, blue, and purple individuals.
6. Thanks to the ability to reproduce asexually, sea anemones can regenerate tissue. That is, after the loss of tentacles, they will quickly restore them.
7. Inside the body there is a certain substance that resembles jelly.
8. With the help of muscles and intestines filled with water, polyps move through the water column. Thus, they are looking for a place for permanent residence.
9. The intestine acts as a skeleton. Once the invertebrates close their oral disc, the anemone is a closed system, sealed off from the outside world.
10. The diet of sea anemones includes small invertebrates or fry, small fish. To paralyze the victim and immobilize it, the polyp uses tentacles, then the invertebrates pull it into its mouth.
11. For residents of some regions of Spain and Italy, sea anemones are considered a delicacy and are widely used in cooking. Favorite dishes of Italians and Spaniards are anemones marinated in a special sauce or sea anemones fried in batter.
12. If a person gets close to the polyp, they may suffer painful burns. After contact with sea anemones, ulcers remain on the hands that do not heal for a long time. The burns can be compared to those caused by jellyfish.
13. Hermit crabs and clown fish are good neighbors for marine inhabitants. Clownfish are able to reproduce the kind of mucus that anemones have. Therefore, sea anemones do not pose a danger to them. Pets hide among their tentacles, protecting themselves from enemies. At this time, they eat undigested food behind the polyps and ensure water circulation.
14. Boxer crabs protect themselves from enemies with the help of sea anemone tentacles. They clamp them in their pincers and attack with poisonous stinging threads. Invertebrates can move freely along the bottom.
15. They got their name due to their resemblance to a beautiful flower - anemone. Many aquarists compare them to asters.
16. More than 1,500 species of sea anemones are known in the world.
17. Anemones swallow all their food. Pebbles and sand also enter the gastric cavity. Undigested food is expelled through the mouth.

Each row contains identical tentacles in color and length. Their length and color differ in different rows.

In case of danger, sea anemones hide in their cavity, retracting their tentacles

Sea anemones are invertebrate animals that thrive in a spacious aquarium. They are interesting to watch. When breeding under artificial conditions, the main thing is to create the appropriate environment in the aquarium and populate them first in the tank. After they find a place for themselves and settle in, they can move in neighbors.

Have you already had this marine predator in your aquarium? Share your experience in the comments!

Anemones or sea anemones

Sea anemones are large coral polyps that, unlike most other corals, have a soft body. Sea anemones are classified as a separate order in the class of Coral polyps; in addition to corals, sea anemones are related to other coelenterates - jellyfish. They received their second name, sea anemones, for their extraordinary beauty and external resemblance to flowers.

Colony of sun anemones (Tubastrea coccinea)

The body of sea anemones consists of a cylindrical leg and a corolla of tentacles. The leg is formed by longitudinal and circular muscles, which allow the body of the sea anemone to bend, shorten and stretch. The leg may have a thickening at the lower end - a pedal disk or sole. In some sea anemones, the ectoderm (skin) of the legs secretes hardening mucus, with the help of which they stick to a solid substrate, in others it is wide and swollen, such species are anchored in loose soil with the help of the sole. The structure of the leg of sea anemones of the genus Minyas is even more surprising: their sole has a bubble - a pneumocystis, which plays the role of a float. These sea anemones swim upside down in the water. The tissue of the leg consists of individual muscle fibers immersed in a mass of intercellular substance - mesoglea. Mesoglea can have a very thick consistency, similar to cartilage, so the sea anemone leg is elastic to the touch.

Single sun anemone with translucent tentacles

At the upper end of the body, sea anemones have an oral disc surrounded by one or several rows of tentacles. All tentacles of one row are the same, but in different rows they can differ greatly in length, structure and color.

Deep sea anemone (Urticina felina)

In general, the body of sea anemones is radially symmetrical, in most cases it can be divided into 6 parts; for this reason they are even classified as a subclass of Six-rayed corals. The tentacles are armed with stinging cells that can shoot thin poisonous threads. The mouth opening of sea anemones can be round or oval. It leads into the pharynx, which opens into a blindly closed gastric cavity (something like a stomach).

Often at the ends of the tentacles you can see swellings formed by accumulations of stinging cells

Sea anemones are quite primitive animals; they do not have complex sensory organs. Their nervous system is represented by groups of sensory cells located at vital points - around the oral disc, at the base of the tentacles and on the sole. Nerve cells specialize in different types of external influences. Thus, nerve cells on the sole of the sea anemone are sensitive to mechanical influences, but do not respond to chemical ones, and nerve cells near the oral disc, on the contrary, distinguish substances, but do not respond to mechanical stimuli.

Bubble-like thickenings at the ends of the tentacles of Entacmaea quadricolor

Most sea anemones have a naked body, but trumpet sea anemones have a chitinous outer covering, so their leg looks like a tall, hard tube. In addition, some species may include grains of sand and other building material in their ectoderm, which strengthens their integument. The color of sea anemones is very diverse; even representatives of the same species can have different shades. These animals come in all the colors of the rainbow - red, pink, yellow, orange, green, brown, white. Often the tips of the tentacles have a contrasting color, which makes them colorful. The size of sea anemones varies within very wide limits. The smallest sea anemone (Gonactinia prolifera) has a height of only 2-3 mm, and the diameter of the oral disc is 1-2 mm. The largest carpet anemone can reach a diameter of 1.5 m, and the sausage sea anemone (Metridium farcimen) reaches a height of 1 m!

The carpet anemone (Stoichactis haddoni) has tiny wart-like tentacles, but can reach a diameter of 1.5 m

Sea anemones are common in all seas and oceans of our planet. The largest number of species is concentrated in the tropical and subtropical zones, but these animals can also be found in the polar regions. For example, sea anemone metridium senile, or sea pink, is found in all seas of the Arctic Ocean basin.

Cold-water anemone metridium senile, or sea pink (Metridium senile)

The habitats of sea anemones cover all depths: from the surf zone, where during low tides sea anemones can literally find themselves on land, to the very depths of the ocean. Of course, few species live at depths greater than 1000 m, but they have adapted to such an unfavorable environment. Despite the fact that sea anemones are purely marine animals, some species tolerate slight desalination. Thus, 4 species are known in the Black Sea, and one is found even in the Azov Sea.

Deep sea tube anemone (Pachycerianthus fimbriatus)

Anemones that live in shallow water often contain microscopic algae in their tentacles, which gives them a greenish tint and partly supplies their hosts with nutrients. Such anemones live only in illuminated places and are active mainly during the day, since they depend on the intensity of photosynthesis of green algae. Other species, on the contrary, do not like light. Sea anemones living in the tidal zone have a clear daily rhythm associated with periodic flooding and drying of the territory.

Anthopleura xanthogrammica lives in symbiosis with green algae

In general, all types of sea anemones can be divided into three groups according to their lifestyle: sessile, swimming (pelagic) and burrowing. The vast majority of species belong to the first group; only sea anemones of the genus Minyas are swimming, and the burrowing lifestyle is characteristic only of sea anemones of the genera Edwardsia, Haloclava, and Peachia.

This green sea anemone lives in the Philippines

Sedentary sea anemones, despite their name, are capable of moving slowly. Usually sea anemones move when something does not suit them in their old place (in search of food, due to insufficient or excessive light, etc.). To do this they use several methods. Some sea anemones bend their body and attach to the ground with an oral disc, after which they tear off the leg and move it to a new place. This tumbling “from head to toe” is similar to the method of movement of sessile jellyfish. Other sea anemones move only the sole, alternately tearing off different sections of it from the ground. Finally, the Aiptasia anemones fall on their sides and crawl like worms, alternately cutting different parts of the leg.

Single tube anemone

This method of movement is also similar to burrowing species. Burrowing anemones actually don’t dig that much, most of the time they sit in one place, and they were called burrowers for their ability to burrow deep into the ground, so that only the corolla of tentacles sticks out. To dig a hole, the sea anemone resorts to a trick: it draws water into the gastric cavity and closes the mouth opening. Then, alternately pumping water from one end of the body to the other, it, like a worm, goes deeper into the ground.

The tallest sea anemone is Metridium farcimen.

Small sessile gonactinia can sometimes swim, rhythmically moving its tentacles (such movements are similar to contractions of the dome of a jellyfish). Swimming sea anemones rely more on the strength of currents and are held passively on the surface of the water by means of pneumocystis.

Lush colony of sea carnations (metridiums)

Sea anemones are solitary polyps, but under favorable conditions they can form large clusters similar to flowering gardens. Most sea anemones are indifferent to their fellows, but some have a quarrelsome “character”. When such species come into contact with a neighbor, they release stinging cells; when they come into contact with the enemy’s body, they cause necrosis of its tissues. But sea anemones are often “friends” with other species of animals. The most striking example is the symbiosis (cohabitation) of sea anemones and amphiprions, or clown fish. Clown fish take care of the sea anemone, clearing it of unnecessary debris and food debris, and sometimes pick up the remains of its prey; the sea anemone, in turn, eats up what is left of the amphiprion's prey. Also, tiny shrimps often play the role of cleaners and parasites, which find refuge from enemies in the tentacles of sea anemones.

Shrimp in the tentacles of a giant sea anemone (Condylactis gigantea)

The cooperation of hermit crabs with adamsia sea anemones has gone even further. Adamsias generally live independently only at a young age, and then they are picked up by hermit crabs and attached to shells, which serve as their home. Crayfish attach the sea anemone not only as if, but precisely with the oral disc forward, thanks to this the sea anemone is always provided with food particles that reach it from the sand disturbed by the cancer. In turn, the hermit crab receives reliable protection from its enemies in the form of the sea anemone. Moreover, he transfers the sea anemone from one shell to another every time he changes his house. If a crayfish does not have an anemone, it tries to find it in any way, and more often, take it away from a happier brother.

Sea anemones perceive their prey differently. Some species swallow everything that touches their hunting tentacles (pebbles, paper, etc.), others spit out inedible objects. These polyps feed on a variety of animal foods: some species play the role of filter feeders, extracting the smallest food particles and organic debris from the water, while others kill larger prey - small fish that inadvertently approach the tentacles. Sea anemones, living in symbiosis with algae, feed mostly on their green “friends.” During the hunt, the sea anemone keeps its tentacles spread out, and when satisfied, hides them in a tight ball, covering itself with the edges of its body. The anemones shrink into a ball and in case of danger or when drying out on the shore (during low tide), well-fed individuals can remain in this state for many hours.

Colony of sun anemones hiding their tentacles

Sea anemones can reproduce asexually and sexually. Asexual reproduction occurs through longitudinal division, when the body of the sea anemone is divided into two individuals. Only in the most primitive gonactinia does transverse division occur, when a mouth grows in the middle of the leg, and then it splits into two independent organisms. Some sea anemones may experience a kind of budding, when several young organisms separate from the sole at once. The ability for asexual reproduction determines a high ability for tissue regeneration: sea anemones easily restore severed body parts.

The same sun anemones, but with extended tentacles

Most sea anemones are dioecious, although males do not differ in appearance from females. Only in some species can both male and female reproductive cells be formed simultaneously. Spermatozoa and eggs are formed in the mesoglea of ​​sea anemones, but fertilization can occur both in the external environment and in the gastric cavity. During the first week of life, sea anemone larvae (planulae) move freely in the water column and during this time they are carried by currents over long distances. In some sea anemones, planulae develop in special pockets on the body of the mother.

Touching the tentacles of large sea anemones can cause painful burns from the stinging cells, but no deaths are known. Some types of anemones (carpet, horse or strawberry, etc.) are kept in aquariums.