Variety of echinoderms. Sea cucumbers: medicinal properties, recipes, photos What is sea lily and sea cucumber

Type Echinoderms - Echinoddermata - are exclusively marine forms with an internal skeleton formed by calcium carbonate crystals, and often with five-ray radial symmetry. This well-known group includes starfish, serpenttails (brittle stars), sea lilies, sea cucumbers (holothurians) and sea urchins. Their diversity was maximum in the Paleozoic: 6 modern classes are known, 15 are extinct.

Class sea ​​urchins- Echinoides - known in the fossil state from the Ordovician, characteristic of post-Paleozoic marine deposits. There are up to 940 species of modern sea urchins.

Sea urchins. Photo: Revital Salomon

The body of sea urchins is usually almost spherical, ranging in size from 2-3 to 30 cm; covered with rows of calcareous plates. The plates, as a rule, are fixedly connected and form a dense shell (shell), which does not allow the hedgehog to change shape. According to the shape of the body (and some other features), sea urchins are divided into regular and irregular. At correct hedgehogs the shape of the body is almost round, and they are built according to strictly radial five-beam symmetry. At wrong hedgehogs the shape of the body is flattened, and they have distinguishable anterior and posterior ends of the body.

With the shell of sea urchins, needles of various lengths are movably connected (using an articular bag with muscle fibers). The length ranges from 1-2 mm ( flat hedgehogs, Echinarachniidae) up to 25-30 cm (diadem hedgehogs, Diadematidae). There is a species completely devoid of needles - Toxopneustes, whose body is dotted with pedicellaria. Quills are often used by sea urchins for locomotion, feeding and protection. In some species, they are poisonous, as they are connected to special poisonous glands. Poisonous species (Asthenosoma, Diadema) are distributed mainly in tropical and subtropical regions of the Indian, Pacific and Atlantic oceans.

In addition to needles, pedicellaria sit on the surface of the shell of sea urchins, and also, at mouth opening, special organs of balance - spheridium. In some species, pedicellaria are also equipped with poisonous glands (Toxopneustes, Sphaerechinus).

The ambulacral system is common in echinoderms. Each ambulacral leg, equipped with a suction cup, passes through the skeletal plates of the shell with two branches (through 2 pores). The ambulacral legs of the underside are used by sea urchins for locomotion and burrowing. The legs of the dorsal side were transformed into organs of touch and breathing. In some species, ambulacral legs, along with needles and pedicellaria, take an active part in the process of cleaning the shell and feeding.

The mouth of sea urchins is located in the center of the lower (oral) side of the body; anal and genital openings - usually in the center of the upper (aboral) side. In regular sea urchins, the mouth is equipped with a chewing apparatus (Aristotelian lantern), which serves to scrape algae from stones. The Aristotelian lantern consists of 5 complex jaws, each of which ends in a sharp tooth. The teeth of the Aristotelian lantern are involved not only in the processing of food, but also in movement (sticking into the ground), and also presumably in burrowing. Irregular sea urchins that feed on detritus do not have a chewing apparatus.

The intestine does not have a radial structure, but is a tube that runs from the mouth opening in a spiral inside the body cavity. Sometimes an adnexal intestine runs along it, opening into the intestine at both ends. Respiratory organs are external skin gills located near the mouth, ambulacral system and the adnexa.

The sense organs and the nervous system are rather poorly developed. In addition to tactile ambulacral legs and spheridia, hedgehogs have primitive ocelli located on the upper side of the body.

Widespread in oceans and seas with normal salinity at depths up to 5 km; are absent in the low-salinity Caspian, Black and partially Baltic Seas. Widespread in coral reefs and in coastal waters, often settling there in crevices and depressions of rocks. Correct sea urchins prefer rocky surfaces; incorrect - soft and sandy soil.

Sea urchins are bottom crawling or burrowing animals. They move with the help of ambulacral legs and needles. According to some assumptions, with the help of the “Aristotelian lantern”, sea urchins drill holes for themselves in the rocks, even granite and basalt, where they hide at low tide and from predators. Other species burrow into the sand or simply cover themselves with pieces of shells, algae, etc.

Almost omnivorous. The diet includes algae, sponges, bryozoans, ascidians and a variety of carrion, as well as mollusks, small starfish and even other sea urchins. The purple hedgehog Sphaerechinus granularis easily copes with the mantis shrimp Squilla mantis. Species living on soft ground swallow sand and silt, digesting small organisms that come with them.

Sea urchins serve as food for lobsters, starfish, fish, birds, fur seals. The main natural enemy of the sea urchin is the sea otter. Having caught a hedgehog, the sea otter either twists it in its paws for a long time (sometimes after wrapping it in algae) to crush the needles and then eats it; or breaks a hedgehog with a stone on his own chest. The number of urchins eaten by sea otters is so great that the intestines, peritoneum and even bones of these marine mammals are sometimes stained with purple pigments of sea urchins.

The reproductive organs consist of vine-like gonads (usually five) that open outwards on the upper side of the body. Sea urchins have separate sexes; sometimes males are somewhat different in appearance from females. Development with planktonic larvae (echinopluteus); some Antarctic species are viviparous - eggs develop under the protection of needles on the upper side of the body or in the brood chamber, so that the young hedgehog leaves the mother fully formed.

Hedgehogs reach sexual maturity and commercial size in the 3rd year of life. According to the estimates of growth rings on the plates of the shells, the age of sea urchins is on average 10-15 years, with a maximum of up to 35 years.

Many sea urchins serve as an object of fishing. They are traditional dish inhabitants of the coasts of the Mediterranean Sea, North and South America, New Zealand and Japan. Their milk is highly valued, and especially caviar, which contains up to 34.9% fat and 19.2-20.3% protein. The shell is good fertilizer for marginal lands, as it contains a lot of calcium and phosphorus. In addition, modern research has established that the pigment isolated from the sea urchin (Subclass Real [correct] sea urchins - Euechinoidea

In Primorye, there are two types of regular sea urchins, which are found in abundance in any bay on coastal stones and rocks. This is a gray hedgehog Strongylocentrotus intermediate and a black hedgehog Strongylocentrotus unarmed.

Of these two species, the dark purple, almost black, unarmed sea urchin bears just longer and thicker quills than those of the gray urchin. Their tips are easily stuck into the body of a careless swimmer and, breaking off, remain in the body. gray hedgehog you won't see it right away. He covers himself with pieces of shells, pebbles, scraps of algae, which he sticks to the body and holds with ambulacral legs. However, this disguise, as a rule, does not save from swimmers. The gray sea urchin is one of the objects of industrial production, and several thousand tons are caught per year. Inochrome), has strong antioxidant activity.

Sea cucumbers are invertebrates of the echinoderm type, in general, molluscs. The currently existing 1150 species, included in 6 orders, have differences in appearance, color, shape of tentacles and rings, as well as internal structure. The closest relatives are sea urchins and stars. In Russia, there are about 100 species of these worm-like animals, the most popular of which are the Far Eastern trepang and Japanese sea cucumber (cucumaria), from which tasty and healthy dishes are prepared.

Appearance of sea cucumber holothuria

Holothurian sea cucumber is a unique inhabitant of the underwater world. It looks like both a large clumsy caterpillar and a huge worm. The soft body of these invertebrates, depending on the species, may be rough or smooth, may be covered with long or short outgrowths. Representatives of holothurians are colored black, brown, green, gray or red. Sea cucumbers, depending on the species, also differ in their size, which varies from 0.5 centimeters to 5 meters, which makes them attractive to sea hunters.

The sea cucumber, the photo of which is presented, is slow and crawls slowly, alternately stretching and contracting. In their normal state, cucumbers lie on one side, which greatly facilitates their capture.

Medicinal properties of holothuria

The sterility of meat, the complete absence of viruses or diseases, the huge content of iodine - all this is a sea cucumber. The medicinal properties of the product allow it to be used as a natural remedy for quick recovery after illness or surgery. Oriental doctors prescribe gourmet trepan meat to accelerate tissue regeneration, stimulate the heart muscle, lower blood pressure, normalization of metabolic processes and even getting rid of tachycardia and bradycardia.

Another useful property of the sea cucumber of holothuria is its therapeutic effect on the joints, which is used in the treatment of arthritis. Substances contained in the meat of a marine life can relieve pain and reduce joint stiffness.

Trepang extract, obtained according to a unique recipe of oriental medicine, has gained wide popularity. Sea cucumber extract has exactly the same beneficial healing properties as its fresh meat. It is especially recommended to use as a dietary supplement for the elderly and those who suffer from chronic diseases. Chinese doctors claim that the extract saturates the body with a complex of necessary elements, improves immunity, the work of the cardiovascular and nervous systems, and prolongs life. Cucumaria sea cucumber tissues contain vitamins of groups C and B, calcium, phosphorus, iodine, chlorine and amino sugars. Toxic substances holothurin are widely used in pharmacology.

Thus, the delicacy meat of marine invertebrates is an excellent raw material for the production of unique medicinal extracts, as well as extracts, on the basis of which medications. And they cook from sea cucumber delicious salads and use it as an independent dish (fried, stewed or canned).

The use of sea cucumber in food

Some types of sea cucumber, which are also called trepangs, are eaten and considered real delicacies. The invertebrate fishery is carried out off the coast of China, Japan and in the south Pacific Ocean, in Russia - on Far East.

Sea cucumber (you can choose the cooking recipe according to your taste) can be fried, dried, canned. It's incredibly delicious and useful product. One “but”: it becomes tasty only when it is cooked with any aromatic products, since they perfectly absorb odors. The Japanese eat it raw, believing that it gives a restorative and healing effect. Indeed, a marine animal contains vitamins, beneficial amino acids and trace elements.

Appetizer of fresh trepang

Thoroughly cleaned and washed trepang is cut into small pieces, poured soy sauce and seasoned with garlic to taste. Marinate 5 minutes. One large trepang is enough for a whole company of six people.

Chinese cuisine recipes from boiled trepang

• Trepang (sea cucumber), the photo of which is presented below, is boiled in boiling water. For the finished dish, they are cut into slices and poured with carrot sauce.
• Sea cucumber makes a very tasty soup if you add fragrant Chinese mushrooms with young bamboo shoots to it. This is super diet food.
• Dried sea cucumbers are pre-soaked for several hours, and then boiled and used in salads or snacks.

Sea cucumber recipe with vegetables

Soak two boiled-frozen cucumbers in cold water for 20 minutes.

Rinse thoroughly and cut into 2.5 cm thick slices.

Fill a deep saucepan halfway with water and place over medium heat.

Peel 100 g of ginger root, cut into cubes and dip into the pan.

When the water boils, put the sea cucumbers there for 2 minutes, then put them in a colander and put them in a dry container.

Peel and cut 2 carrots and 2 onions into thin strips, also chop 200-300 g of cabbage.

Separately cut into cubes 200 g smoked brisket.

Put a frying pan with 3 tbsp on medium heat. oil and put the cabbage, simmer for 15 minutes.

Add a little water so that it does not burn, pepper and put the smoked brisket, simmer, stirring, for 15 minutes.

In another pan, fry in 3 tbsp. butter onion and carrot, add finely chopped green onion and parsley (3 feathers each), sea cucumbers, simmer for 5 minutes.

When the cabbage is translucent, add the mixture from the second pan, sprinkle with sesame seeds and cover. Stirring occasionally, cook the dish for 10-15 minutes over low heat. Salt a little, let it brew for 5-7 minutes. Served hot with spicy sauces.

sea ​​cucumber caviar recipe

Boiled sea cucumber is ground in a large meat grinder.

Onions are cut, carrots are rubbed.

Sea cucumber with vegetables is stewed for 15 minutes in a pan in oil, you can add fresh tomatoes or pasta. Salt and pepper to taste. Can be seasoned with soy sauce.

"Skoblyanka" from trepang

Salt is fried in a pan, 100 g is added vegetable oil and fried 2 onions, cut into rings.

Boiled trepang is cut across into rings and added to the pan with onions.

After a couple of minutes, two large tomatoes sliced ​​\u200b\u200bin circles or two tablespoons of tomato paste, salt, black pepper are placed there.

Let it boil for a few minutes, turn off the heat, cool. Squeeze a clove of garlic and let it brew under the lid.

Often on sale you can find trepangs in dried form, covered with black coal dust - this protects them from spoilage. To prepare a dish from such a mollusk, it must first be kept for two days in cold water, periodically replacing the water. But trepang will increase several times in volume. Before subjecting it to heat treatment, the abdomen is cut and cleaned of the insides.

Boil trepang for 2-3 hours until soft. And then you can use it for cooking hodgepodge, cabbage soup, all kinds of salads, snacks, vegetable casseroles and other dishes. Whatever you choose as a culinary experiment, in any case, you will be satisfied!

Echinoderms are peculiar animals. They cannot be compared in structure with other types. these animals are reminiscent of a flower, a star, a cucumber, a ball, etc.

History of study

Even the ancient Greeks gave them the name "echinoderms". Representatives of this species have long been of interest to man. The history of their study is connected, in particular, with the names of Pliny and Aristotle; and in the 18th and early 19th centuries they were studied by many famous scientists (Lamarck, Linnaeus, Klein, Cuvier). most zoologists at that time correlated them with either coelenterates or worms. I. I. Mechnikov, a Russian scientist, found out that they are related to the enterobranchs. Mechnikov showed that these organisms are closely related to representatives of chordates.

Variety of echinoderms

In our time, it has been established that echinoderms are animals that belong to the group of the most highly organized invertebrates - deuterostomes. They appeared on our planet more than 520 million years ago. The remains of echinoderms are found in sediments dating back to the early Cambrian. This type includes about 5 thousand species.

Echinoderms are benthic, most of which are free-living organisms. Less common are those attached to the bottom with a special stalk. The organs of most organisms are located along 5 rays, but their number in some animals is different. It is known that the ancestors of echinoderms had bilateral symmetry, which from modern species have free-swimming larvae.

Internal structure

In representatives of echinoderms, a skeleton develops in the subcutaneous connective layer, consisting of calcareous plates and needles, spines, etc. on the surface of the body. Like chordates, these organisms secondary cavity the body is formed by separating mesodermal sacs from the intestines. The gastropore during their development overgrows or transforms into the anus. In this case, the mouth of the larva is formed anew.

Echinoderms have circulatory system. Nevertheless, their respiratory organs are rather poorly developed or completely absent. It is necessary to briefly describe other features of echinoderms. These animals lack special nervous system organisms of interest to us. It is located partially in the skin epithelium or in the epithelium of invaginating parts of the body.

External structure

Characteristics of echinoderms should be supplemented by features external structure these organisms. The outer epithelium of the main part of echinoderms (with the exception of holothurians) has cilia that create a flow of water. They are responsible for the supply of food, gas exchange and cleansing the body of dirt. In the integument of echinoderms there are various glands (luminous and poisonous) and pigments that give these animals an amazing color.

The skeletal elements of starfish are calcareous plates, which are placed in longitudinal rows, usually with spines protruding outwards. The body of sea urchins is protected by a calcareous shell. It consists of a series of plates tightly connected to each other, with long needles sitting on them. Holothurians have calcareous bodies that are scattered over their skin. The skeleton of all these organisms is internal in origin.

Musculature and ambulacral system

The musculature of these animals is represented by muscular bands and individual muscles. It is developed quite well, as much as this or that animal is mobile. In most species of echinoderms, the ambulacral system is used for touch, movement, and in some sea urchins and sea lilies it is for breathing. These organisms are dioecious; they develop with larval metamorphosis.

Classification of echinoderms

There are 5 classes of echinoderms: brittle stars, sea stars, sea urchins, sea lilies and sea cucumbers. The type is divided into 2 subtypes: freely moving echinoderms are represented by brittle stars, holothurians, sea urchins and starfish, and attached by crinoids, as well as some extinct classes. About six thousand modern species are known, as well as twice as many extinct ones. All echinoderms are marine animals that live only in salt water.

Sea stars

The most famous representative of the type of interest to us is the starfish (a photo of one of them is presented above). These animals belong to the class Asteroidea. Sea stars are not accidentally given this name. In their form, many of them are a five-pointed star or a pentagon. However, there are also such species, the number of rays of which reaches fifty.

See what an interesting body the starfish has, the photo of which is presented above! If you turn it over, you can see that on the underside of the rays there are rows of small tubular legs with a suction cup at the end. The animal, sorting through them, crawls along the seabed, and also climbs vertical surfaces.

All echinoderms have the ability to quickly regenerate. In a starfish, every ray that has separated from the body is viable. It immediately regenerates and a new organism emerges from it. Most starfish feed on the remains of organic matter. They find them in the ground. Their diet also includes fish carcasses and algae. However, some representatives of starfish are predators that attack their prey (non-motile invertebrates). After the prey is found, these animals dump their stomach out. Thus, digestion in some predatory starfish is carried out externally. The rays of these animals have very powerful muscles. It allows them to easily open the clam shells. Starfish, if necessary, can crush its shell.

The most famous among them is Acanthasterplanci - the crown of thorns. This worst enemy marine coral reefs. There are about 1500 species in this class (type echinoderms).

Sea stars are able to reproduce both sexually and asexually (regeneration). The bulk of these animals are dioecious organisms. They fertilize in water. The organism develops with metamorphosis. Some starfish live up to 30 years.

Serpenttails (brittle stars)

These animals are very reminiscent of stars: they have thin and long rays. The ophiuroids (type echinoderms) do not have liver appendages, anus and hindgut. In their way of life, they are also similar to starfish. These animals are dioecious, but are capable of both regeneration and asexual reproduction. Some species are luminous forms.

The body of the serpentine (ofiur) is represented by a flat disk, the diameter of which is up to 10 cm. 5 or 10 thin long segmented rays depart from it. Animals use these curving beams to move around, with which they crawl along the seabed. These organisms move in jerks. They stretch forward two pairs of their "arms", after which they sharply bend them back. Serpenttails feed on detritus or small animals. Ophiurs live on the bottom of the sea, sponges, corals, sea urchins. There are about 2 thousand of them. These animals have been known since the Ordovician.

sea ​​lilies

Echinoderms are very diverse. Examples of crinoids that are also of this type are presented above. These organisms are exclusively benthic. They drive sedentary image life. It should be emphasized that crinoids are not plants, but animals, despite their name. The body of these organisms consists of a calyx, stem, and arms (brachioles). They use their hands to filter food particles from the water. Most modern species are free-floating and stemless.

Stemless lilies can crawl slowly. They can even swim in water. Their diet consists of small animals, plankton, algae residues. The total number of species is estimated at 6 thousand, of which less than 700 are currently represented. These animals have been known since the Cambrian.

Beautifully colored species of crinoids live mainly in the seas and oceans of the subtropics. They are attached to various underwater objects. It is believed that this, however, in the Mesozoic and Paleozoic era their role in the waters of the seas and oceans was very great.

Sea cucumbers (holothurians)

These organisms are called differently: sea-pods or holothurians. They represent a class of invertebrates such as echinoderms. There are species that humans eat. Common name edible holothurians - "trepang". Trepang is mined on a large scale in the Far East. There are also poisonous holothurians. They make various medicines(for example, holothurin).

About 1150 species are currently represented sea ​​cucumbers. Their representatives are divided into 6 groups. The Silurian period is the time to which the oldest fossils of holothurians belong.

These organisms differ from other echinoderms in their oblong, spherical or worm-like shape, as well as the reduction of the skin skeleton and the fact that they do not have protruding spines. The mouth of these animals is surrounded by a corolla, consisting of tentacles. With the help of them, holothurians capture food. These animals are benthic, although very rare and living in the silt (pelagic). They lead a sedentary lifestyle. Holothurians feed on small plankton or silt.

sea ​​urchins

These animals live at the bottom or in the bottom. The body of most of them is almost spherical, sometimes ovoid. Its diameter is from 2-3 to 30 cm. Outside, the body is covered with rows of spines, calcareous plates or needles. As a rule, the plates are interconnected motionlessly, forming a shell (dense shell). This shell does not allow the animal to change shape. Today, there are about 940 species of sea urchins. The largest number species were introduced in the Paleozoic. Currently, there are 6 classes, while 15 are extinct.

As for nutrition, some sea urchins use dead tissue (detritus) for food, while others scrape algae from stones. In the latter case, the animal's mouth is equipped with a special chewing apparatus called the Aristotelian lantern. In appearance, it resembles a drill. Some species of echinoderms (sea urchins) with its help not only get food, but also modify rocks by drilling holes in them.

The value of sea urchins

These animals are a valuable type of biological resources of the sea. Commercially interesting mainly In Japan and other countries of the Asia-Pacific region, it is a delicacy product. The caviar of these animals contains many biologically active substances. Scientists believe that the elements that are present in it can be used for cancer as a therapeutic and prophylactic agent. In addition, they normalize blood pressure, increase potency, remove radionuclides from the human body. It has been proven that eating caviar increases resistance to various infections, helps with gastrointestinal diseases, reduces the effects of radiation therapy, improves the functions of the genital and thyroid glands, and the cardiovascular system.

Considering the above, it is not surprising that the sea urchin is a marine echinoderm that is becoming a coveted dish. For example, the inhabitants of Japan eat about 500 tons of caviar of this animal every year. in kind and as food additives. Incidentally, using this food product such long duration life in this country where people live an average of 89 years.

In this article, only the main echinoderms were presented. We hope you remember their names. Agree, these representatives of the marine fauna are very beautiful and interesting.

Or caterpillars. They are able to shrink strongly even with a slight touch, therefore they are sometimes associated with egg capsules.

Sea cucumber - echinoderm an invertebrate mollusc with more than a thousand species. Varieties of these marine life differ in size, tentacles, as well as the structure of some organs.

They have a wrinkled, leathery body that resembles a cucumber due to its oval shape. On thick skin, growths resembling spikes are noticeable. On one side of his body is a mouth surrounded by tentacles, on the other - an anus. Sea cucumbers can be very different colors - black, brown, green, gray, red.

Sea cucumbers also differ in size - some species look like dwarfs and reach sizes from a few millimeters to several centimeters, other varieties can reach a length of up to two or even five meters. For such giants miners are hunting with special enthusiasm. Sea urchins and starfish are closest to sea cucumbers.

Pictured is a sea cucumber

The most ancient sea cucumbers were already known in the Silurian period, the very name "sea cucumber" belongs to the Roman philosopher Pliny, and Aristotle created the first descriptions of some species.

About a hundred species of these mollusks live in Russia, the most popular is the Japanese variety sea ​​cucumber - cucumaria. This type of sea cucumber is distinguished useful composition and beautiful palatability, and are often used in cooking. Trepangs are the types of sea cucumbers that can be eaten.

Sea cucumber lifestyle and habitat

sea ​​cucumbers meet in different parts ocean, and in shallow waters close to the coast, and in deep-sea trenches, and in coral reefs, in tropical latitudes. They are common in sea ​​depths practically all over the world.

Holothurians are slow and lazy, they crawl along the bottom, and this makes them easy prey for hunters. Most of the time they lie on the bottom, "on their side". Deep-sea varieties may have elongated ambulacral legs that serve as animal stilts and help move along the bottom and rocks.

The musculature of echinoderms is developed enough to move along the bottom and contract sharply in case of danger. Some species are able to attach themselves to rocks or burrow into silt. Holothurians themselves can become prey for starfish, fish, crustaceans or gastropods.

Similarly, in the event of an attack or other danger, holothurians "explode" - they scatter their body to pieces. While the opponent chooses a tastier piece, at this time the front part of the cucumber is saved.

In case of danger, the sea cucumber can throw back part of the intestine for a distracting maneuver.

The body of echinoderm mollusks subsequently quickly regenerates. Sea cucumbers are animals, which can regenerate if half of their torso is preserved, they can recover even from a quarter of their body. The regeneration process can take from one and a half to five weeks.

Sea cucumber nutrition

How do sea cucumbers hunt? All types of sea cucumbers have special tentacles placed around their mouths. The number of tentacles can vary from 8 to 30.

The tentacles are usually short, designed to collect nutrients from the ground surface. Holothurians also have branched tentacles that can cover a large expanse of water in order to catch prey.

Their diet consists of plankton, plants, small animals and organic remains that can be extracted from bottom sand or silt. They are sometimes called marine orderlies because they clean the bottom surface of the remains of dead animals, using these organic substances as a nutrient.

Features of the nutritional system of holothurians were carefully studied by American scientists. They found that holothurians feed mainly through the mouth, but the anus can also perform the function of capturing food, which in these protozoan invertebrates is also involved in respiratory system. Respiratory functions in these invertebrates are also performed by water lungs.

In Russia, cucumaria and other types of sea cucumbers are common in Sakhalin, in Primorye, as well as in the Seas of Okhotsk, Japan and Barents, at a depth of half a meter to a hundred meters.

Reproduction and lifespan of sea cucumber

Holothurians are hermaphrodites; they produce male and female germ cells alternately, sometimes even simultaneously. They reproduce by spawning, they have eggs of a bright green color, larvae capable of swimming are hatched from the eggs.

Spawning occurs more often in the evening or at night, perhaps darkness matters. Cucumaria spawns twice, in May and July. Holothurians living in Atlantic Ocean, spawn off the coast of Sweden in autumn, from October to December. Some species can spawn all year round. The larvae swim in plankton for about two weeks, then sink to the bottom.

Tentacles sea cucumber collects food from the bottom

About 30 species of holothurians have a gender and are divided into male and female individuals. They take care of the young and carry the young on the surface of the mother's body.

Rare cases reproduction by division has also been recorded and described by scientists: half of the body is able to recover to full volume. Holothurians live long enough, from five to ten years.

Due to the great popularity of cucumaria and its demand as a culinary product, as well as in pharmacology, it is practiced artificial breeding sea ​​cucumbers, including in Russia, in the Far East.

About useful sea ​​cucumber properties Ancient Oriental medicine also knew it, it has long been called sea ginseng. Cucumaria meat is practically sterile, not affected by viruses and bacteria, these mollusks are unusually rich in useful substances, microelements, especially iodine, as well as fluorine, calcium, amino acids and others.

Sea cucumbers are very low in calories, so their products can form the basis of a diet for those who want to lose weight. This product is used as healing remedy, stimulating the body's defenses, for people suffering from increased fatigue, loss of strength. Sea cucumbers help a person recover quickly after surgery or a long illness.

Benefits of Sea Cucumber Meat for health, it normalizes metabolism, stimulates the heart, can help lower blood pressure, promotes rapid tissue regeneration, so it is used during operations.

Sea cucumbers have a healing effect on the joints, help with arthritis. Also made from sea cucumbers nutritional supplements and pharmaceuticals.

You can buy sea cucumber not only for the sake of useful and medicinal properties - they are used to prepare delicious dishes. Sea cucumbers make excellent salads, invertebrate molluscs, having previously cleaned, fried and stewed, and also preserved. Some types of sea cucumber are considered delicacies and attract a lot of gourmet attention.

sea ​​urchins And holothurians belong to echinoderms, like starfish. They have the characteristic abilities of echinoderms - thin tube legs, and many species also have numerous needles, which they use both for protection and for movement, as if on stilts. Some types of sea urchins are poisonous. sea ​​urchins are rounded, flattened or spherical shape body. This group got its name from the needles found in most species. Sea urchins, like and, have five-ray symmetry. But their rays grow together, forming a spherical body. Sea urchins can walk slowly on their quills, in addition, they can crawl with the help of very long flexible tubular legs. Sea urchins feed on algae and small animals like those that cover the surface of water rocks. Some species, such as the heart-shaped hedgehog, have a more elongated body shape, resembling a heart. This structure makes it easier for them to burrow into the sand. There is a species called sea potatoes. Its brown, potato-like shell or shell can be found on the beach.
Holothurian also called sea ​​cucumbers for an elongated warty body resembling a cucumber. Unlike other echinoderms, holothurians have a soft body in a dense leathery shell. The animal's mouth is surrounded by retractable tentacles. Holothurians slowly move along the seabed with the help of three rows of tubular legs. If the holothurian was disturbed or someone attacked it, it is able to throw out the insides, including the stomach and intestines, on the enemy. This sticky mass repels most predators and keeps even lobsters at bay. Holothuria easily restores lost organs.

Other echinoderms:

sea ​​urchins
- 950 species
- Spherical, sometimes with spikes
- Beams fused

Holothurians
- 1150 species
- long oblong body
- No rays
- Tentacles around the mouth

Other marine animals:

tunicates (sea squirts)
- 1400 species
- Sedentary or plankton filter feeders
- Larvae are more complex than adults

lancelets
- 25 types
- Small, up to 10 cm
- fish body
- No eyes or fins