Sea urchins belong to the class of echinoderms and there are up to 940 species. They are very different in size, color and appearance. Their size varies from 2 to 30 cm. The body of sea urchins is covered with calcareous plates, which are tightly interconnected and form a shell, i.e. shell, so that the sea urchin cannot change its shape. In general, sea urchins come in a variety of shapes, and depending on this, urchins are distinguished from regular and irregular shapes. Regularly shaped sea urchins are always round and symmetrical, while irregularly shaped sea urchins clearly show the front and back of the body.
Why do sea urchins need such long and sharp spines? For movement, nutrition and protection. There are some types of sea urchins in which these spines are poisonous, but in general, most sea urchins are not dangerous.
If you take a good look at a sea urchin, you can see a mouth and spheridia on its body, i.e. balance organs. They also have respiratory and tactile organs. The mouth is located in the lower part of the body, in the center, the anus and genital opening are in the center of the upper side. Hedgehogs of the correct form have a chewing apparatus. Even sea urchins have sharp teeth, which are not only involved in the processing of food, but also for movement and digging holes. Irregular hedgehogs do not have a chewing apparatus, they feed on detritus (this is a substance consisting of the remains of invertebrates, secretions and bones of vertebrates, etc.).
Sea urchins love to live in seas and oceans with a normal average salt content, at a depth of up to 7 km. Most of all they are common on coral reefs, not far from the coast. They like to settle in rock crevices, near rocks and reefs. Regularly shaped sea urchins choose rocky surfaces for life, while irregularly shaped urchins prefer soft sandy surfaces. Sea urchins crawl on the surface and burrow, and they move with the help of legs. Some marine organisms hide among the spines of sea urchins, thus protecting themselves from other marine creatures.
Who eats sea urchins? They are eaten by fish, starfish, lobsters, fur seals, sea otters and even birds.
On average, sea urchins live 10-15 years, but sometimes their age reaches 35 years. They begin to breed in the 3rd year of life.
Residents of the coasts of the Mediterranean Sea, North and South America, New Zealand and Japan eat sea urchins. I myself have seen more than once how the Filipinos caught them and cooked them, often offered to try. But mostly sea urchins are eaten raw, namely their caviar and milk, which tastes like salted mushrooms, according to the stories of my parents, who recently tried them raw.
Sea urchins rarely live alone, usually they are united by a ‘company’.
If you step on a sea urchin and its needles remain in your foot, you need to smear this place with lemon or lime juice. Everything will be gone the next day. It makes no sense to get needles, because. you only open the leg, and the needles break.
This is how hedgehogs hide, only needles are visible:
The greatest danger to scuba divers is sea urchins, the body of which often has a spherical shape. At one of the poles, this ball is somewhat wrinkled - this is the oral side of the animal. The mouth opening is located here and the echinoderms crawl along the bottom with the same side. The skeleton of sea urchins is more developed than that of other echinoderms. Only a small space remains soft near the mouth and around the anus, which is located on the dorsal side of the body. The surface of the skeletal plates is covered with numerous tubercles, to which the needles are attached.
Sea urchin quills- these are cylindrical dense lime sticks, movably woven with a shell skeleton, which allows them to easily rotate in all directions. Needles perform not only a protective function, but sometimes take part in the movement of the animal. The needles of some hedgehogs reach a length of up to 30 cm. Among ordinary needles, there are needles that look like tweezers, which are grasping organs. These modified tweezers are called. With their help, the sea urchin cleans its "suit". Some tweezers play a protective role, as they contain poisonous glands. The poison they secrete is quite strong in action. Transformed into tweezers, the needles are somewhat shorter than usual, therefore, during protection, ordinary needles are retracted in different directions, opening poisonous devices and giving them the opportunity to act.
In some species of tropical sea urchins, some of the usual needles are also poisonous, since they also have a gland at the free end. About 80 species of marine echinoderms are dangerous for humans.
As to whether the same animal has tweezers and regular needles, scientists disagree. So, according to Halsted, y of one kind there are either those or other needles. Moreover, the scientist believes that although they write about the toxicity of ordinary needles in sea urchins, this has not been experimentally proven.
Among sea urchins, the most numerous black sea urchins with long needles. They are distributed from East Africa to Polynesia, China, Japan. Close species are found in the West Indies, off the Hawaiian Islands. round sea urchin lives in waters from East Africa to Japan, Japanese sea urchin- in the waters of Japan, that is, the habitat of sea urchins covers the tropical and subtropical regions of the Indian, Pacific and Atlantic oceans. The most dangerous and frequently encountered are the round sea urchin and the black sea urchin with long spines. Some sea urchins, in particular the black sea urchin with long spines, are quite beautiful in coloration. The needles of these animals are very sensitive. The sea urchin quickly reacts to the slightest change in environmental conditions, and its needles immediately go in the direction of the irritant, which may be an unexpected, strong movement of water caused by something or a shadow of a person accidentally falling on the animal.
Modified needle-tweezers consist of two flaps - parts. When protected from enemies, these flaps open and then slam shut on the body of the victim. Their ends easily pierce the skin, introducing poison. Through the holes in the leaf, a poisonous liquid is released, which has a whitish color.
The injection sites, where the ends of the poisonous needles of the sea urchin fell, begin to itch, there is a strong burning sensation, the skin turns red, swells, and hurts. Loss of sensation may occur, up to muscle paralysis. Injections with needle-tweezers (pedicellaria) are more difficult to tolerate. According to a number of researchers, the toxins secreted by their glands act in a directed way, affecting the nervous system. In addition to paralysis of the motor muscles, respiratory distress can occur, which is very dangerous while working underwater.
In the most severe cases, the person dies. There are known cases of people dying under water, when, after being hit by the poison of sea urchins, they could not rise to the surface. In less severe cases of intoxication, the pain decreases after about 15-20 minutes, and other symptoms of poisoning disappear after three to four days. True, after the disappearance of pain, paralysis still persists (for 6 hours, and sometimes longer).
If sea urchins are poisoned, measures must be taken to reduce the absorption of the poison. It is necessary to sharply limit the mobility of the victim, quickly remove fragments of needles from the wounds and deliver the victim to the hospital.
Who is this Sea Urchin? With what and why do these strange people sitting in a gloomy corner of an expensive Japanese restaurant eat it? Why are they not speaking loudly, looking suspiciously in our direction, and clearly not in a hurry to share their unusual gastronomic tastes with the rest of humanity, ignorant of the Sea Urchins?
Probably, a frequenter of fast food establishments, seeing how someone eats sea urchin caviar, will immediately classify such a person as a marginal raw food eater, consciously striving to exterminate all marine inhabitants in especially perverted ways. However, you will be pleasantly surprised when you realize that fresh Sea Urchin caviar is unusually delicate in taste, and with its milky-cool fragrant structure, it will remind you of the pulp of a ripe tropical papaya.
Sea urchins are not the most common dish in Spanish cuisine, however, they are quite traditional. In restaurants in Spain, it can usually be ordered raw or with minimal changes from the chef. However, in restaurants of the highest category, for example, those with a Michelin star, sea urchin caviar can be served as part of the most sophisticated dishes.
Usefulness of sea urchin caviar
If you decide to order this unusual seafood dish and the hedgehog itself is still alive on the tray in front of you, and its needles are moving slowly, then you can eat a real elixir of youth and, with the flesh of a marine inhabitant, absorb dozens of unique nutrients, vitamins and bioactive compounds. The benefits of eating sea urchins will make themselves felt quickly: after half an hour, a slight pleasant feeling of a surge of strength will appear throughout the body, and after an hour, a clearly distinguishable physiological euphoria will flood in, which can be compared with the impact of a good massage, sports training or even sex.
So, having eaten a portion of sea urchin caviar on a gloomy February morning, we will receive:
- fat-soluble vitamins A, D, E and water-soluble vitamins C, B6, P - niacin, B2 - riboflavin, B1 - thiamine, folacin, etc.
- biologically active substances: gomarin, carnitine, dopamine and norepinephrine, sterols, peptides, fatty acids, terpenoids, aromatic compounds and saponins.
- protein mixtures with a sufficiently high specific activity of thymidine and thymidylate kinase enzymes.
- bioactive suspension with the presence of two types of endodeoxyribonucleases, which are designated respectively as Ca, Mg-dependent and acidic metal-independent DNases.
- current pigments carotenoids, naphthoquinones and melanin; additionally, depending on the season, lipofuscin is present.
- The most important pigments for proper human metabolism are the carotenoids P-carotene and P-echinenone.
In other words, sea urchin caviar
- is a powerful support for the nervous system during periods of stress overload, moments requiring increased concentration and long periods without the possibility of sleep;
- significantly activates the work of the reproductive and circulatory systems of a person, strengthens the capillaries of the brain in a mysterious way, serving as a powerful prevention of stroke and sclerosis;
- is able, with daily use, to protect us from seasonal epidemics of respiratory infections in large cities, to stabilize the function of the endocrine system;
- contributes to the rapid removal from the body of toxins, narcotic substances and heavy metals, including radioactive substances.
The benefits of eating sea urchin caviar are difficult to overestimate. The only question is whether you are ready to enjoy the absorption of such a strange substance in the indicated amount. After all, any product, in order to be digested favorably and bring the benefits declared by science to your body, must be accepted by your body, first of all, psychologically. And this moment, except for yourself, no one can shake it!
How to eat sea urchin caviar
Those who like to eat sea urchins have about 3-4 months a year when they are edible: in Spain this is the period from December to April, since later the water warms up and catching sea urchins is no longer recommended due to sanitary and taste restrictions.
In the ideal case, you need to eat sea urchin caviar with a dessert spoon directly from its own shell, opened by a skilled chef. To accompany hedgehogs, ice-cold white wine is ideal, preferably with a fruity tinge.
The optimal portion of fresh sea urchin caviar to eat at a time is 70-120 grams, depending on appetite. Some Japanese restaurants in Spain serve sea urchin caviar in the "sashimi" style, that is, raw, but completely ready to eat, sometimes seasoned with savory sauces. The only difference with the usual way of enjoying a delicacy is that you do not have to extract the delicacy from the hedgehog yourself. An experienced chef will do this for you, but somewhat deforming the “tongue” itself when serving on an exquisite plate.
Gourmet Sea Urchin Caviar Intake Plan
Order yourself Japanese oysters for lunch or dinner - seasoned with Ponzu sauce, then anguilla (aguilla), fried with garlic (these are conger eel fry, an expensive and rare product), the next step will be two dozen oven-baked shrimp from Palamos , and at the end, and as a main course, a huge ice tray with a dozen live sea urchins.
The perfect drink for such a meal would be Meursault-Charmes 1997 French white wine. This is not the cheapest option for wine, but if it costs you no more than 200 euros per bottle, do not deny yourself a little pleasure.
Biology
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 correct and wrong. In regular hedgehogs, the body shape is almost round, and they are built according to strictly radial five-ray symmetry. Irregular hedgehogs have a flattened body shape, and they have distinguishable front and rear ends of the body.
sea urchin shell
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, Echinarachnidae) up to 25-30 cm (diadem hedgehogs, Diadematidae). There is a species completely devoid of needles - toxopneustes ( Toxopneustes), whose body is littered 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 the 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 the mouth opening, special organs of balance - spheridium. In some species, pedicellariae are also provided with venom 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) sides of the body; anal and genital openings - usually in the center of the upper ( aboral) sides. In regular sea urchins, the mouth is equipped with a chewing apparatus ( aristotelian lantern), serving 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 in a spiral inside the body cavity. Sometimes it goes along adnexa opening into the intestine at both ends. Respiratory organs are external skin gillslocated near the mouth, the 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.
Lifestyle and nutrition
Widely distributed in oceans and seas with normal salinity at depths up to 7 km; are absent in low-salinity Caspian, Black and partially Baltic seas. They are widely distributed on 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 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. purple hedgehog Sphaerechinus granularis easily copes with 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.
Reproduction and development
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 third 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.
Economic importance
Many sea urchins serve as an object of fishing. They are a traditional dish of the 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 a 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 ( echinochrome) has strong antioxidant activity.
Gallery
Notes
see also
- Common flat sea urchin ( Echinarachnius parma).
- Green sea urchin ( Strongylocentrotus droebachiensis).
- Purple sea urchin ( Strongylocentrotus purpuratus).
- Gray sea urchin ( Strongylocentrotus intermedius).
- Slate sea urchin ( Heterocentrotus mammillatus)
Links
- // Encyclopedic Dictionary of Brockhaus and Efron: In 86 volumes (82 volumes and 4 additional). - St. Petersburg. , 1890-1907.
Wikimedia Foundation. 2010 .
See what "Sea urchins" are in other dictionaries:
- (Echinoidea), a class of echinoderms. The body is spherical, disc-shaped (sea dollar) or heart-shaped, covered with a shell of fused calcareous plates with numerous. needles and pedipellaria. Diam. shell from 2 3 mm to 30 cm. In a fossil state ... ... Biological encyclopedic dictionary
A class of invertebrates such as echinoderms. The body (diameter from 2 3 mm to 30 cm) is spherical, disc-shaped or heart-shaped, covered with skeletal plates with movable needles. OK. 800 species. They are widely distributed, live on the bottom, from the littoral to ... ... Big Encyclopedic Dictionary
A class of invertebrates such as echinoderms. The body (from 2 3 mm to 30 cm in diameter) is spherical, disc-shaped or heart-shaped, covered with skeletal plates with movable needles. About 800 species. They are widely distributed, live on the bottom from the littoral to ... encyclopedic Dictionary
- (Echinoidea), a class of marine invertebrates such as echinoderms (Echinidermata). The body is usually almost spherical, covered with movable spines. In the skin layer there is a shell (shell) of densely connected calcareous plates. Five of their radial rows ... ... Collier Encyclopedia
Echinoidea sea urchins Class of echinoderms with a body of a spherical or similar shape, covered with numerous spines; dioecious, external fertilization (occasionally live birth), have a mobile larva, about ... ... Molecular biology and genetics. Dictionary.
The history of the existence of sea urchins (lat. Echinoidea) - bottom animals included in a vast class called "Echinoderms" - has been around for more than five hundred million years. Their life cycle begins from the moment when the male ejects a stream of sperm directly into the water, and the nearby female lays eggs here. Fertilized eggs go through several stages of development and in about a month turn into young hedgehogs with all the features of an adult.
Sea urchins live in almost all seas and oceans and lead a bottom lifestyle. The main condition for their comfortable existence is salt water, therefore, in such low-salt seas as the Black and Caspian, you will not see them. The most dangerous types of poisonous sea urchins are found in the tropical waters of the Atlantic, Indian and Pacific Oceans.
According to the shape of the shell, consisting of many fixed calcareous plates, sea urchins are divided into regular and irregular. As the name implies, correct hedgehogs have a round symmetrical shell, while incorrect hedgehogs have a flattened one. Very important organs for the sea urchin are attached to the shell - needles that can move in different directions and perform several functions at once - with their help, hedgehogs move, protect themselves from predators and get food.
In some species, the needles are almost invisible - no more than two millimeters, the needles of others are long, about thirty centimeters, sometimes poisonous. The most common colors of sea urchins are purple and pink, less common are brown, green, black, white, red.
Sea urchins, like other echinoderms, have a unique hydraulic system responsible for vital functions such as breathing, touch, movement, and excretion. Hundreds of cylindrical tubes (legs) with suction cups at the end penetrate the shell of the sea urchin.
Filled with water, the legs stretch and attach to the nearest surface, then, due to a change in pressure, they contract again, and the animal moves. With the help of the lower legs, sea urchins burrow into the sand or clean the shell of food debris, and the upper ones serve as organs of touch and breathing.
The mouth of the sea urchin, located on the underside of the body, is equipped with a special chewing apparatus called the "Aristotelian Lantern". This device is equipped with five jaws at once, each of which is crowned with a strong sharp tooth that does not stop growing throughout the life of a sea urchin. Sea urchins use their unique jaws as a scraper, peeling algae off rocks, crushing prey or burrowing.
Getting food for sea urchins is not particularly difficult - these omnivorous creatures are ready to swallow not only algae, mollusks, sponges, but also their own kind - small sea urchins and starfish. In turn, fish, birds, lobsters will not refuse to eat sea urchins.
The most important sea urchin hunter is the sea otter. In order not to get hurt by sharp needles, the sea otter wraps the hedgehog in algae or breaks it with a stone right on its chest. Hiding from predators, sea urchins climb into narrow gaps between stones, increasing them to the desired depth with the help of needles and teeth.
