Sea cucumber - what it is and how it looks, types and useful properties, cooking recipes with photos. Holothuria: interesting facts and features Sea cucumber refers to

Niramin - Aug 31st, 2015

Sea cucumbers or sea cucumbers, which are also called egg-pods, are part of the group of echinoderm marine animals. These monsters, resembling a furry sausage, live at the bottom of the seas almost all over the world.

Holothurians of edible species are classified as delicacies and are called "trepangs". Canned food is prepared from them, they are fried and dried, they are also consumed raw. On a diet with the inclusion of sea cucumber, extra pounds are quickly lost.

These animals are brightly colored and can be black, red, blue or Green colour. They play a very important role in cleansing the seas and oceans, as they feed on the remains of dead animals.

The size of egg-pods is from 10 to 40 cm. However, there are also dwarfs reaching several mm, and giants 2-5 m. These echinoderms resemble large worms.

Amusing "cucumbers" crawl on their side.

Mouth sea ​​cucumbers devoid of any devices for grinding food and surrounded by tentacles that have great importance for both touch and breath.

When threatened, the sea cucumber explodes, scattering parts of its body. While the enemy chooses a tasty piece, the front part of the cucumber escapes and then grows the missing body parts for itself. All missing organs are restored within 1.5-5 weeks.

These sea ​​monsters don't have a brain nervous system consists of a ring and several nerves.
Sea cucumbers breathe through the anus.

They are capable of self-reproduction. And yet, preference for "cucumbers" is given to mating.
Most types of sea cucumbers live up to 10 years.

We offer you a selection beautiful photos sea ​​cucumbers:

Photo: Trepang is an edible sea cucumber.

Sea cucumber Red



Green sea cucumber.

Black sea cucumber







Holothurian brown

Video: A strange way of protection in sea cucumbers

Different species live at different depths. Some live near the coast. Others are found in deep sea trenches. It is known that several species of sea cucumbers live at the bottom of the Mariana Trench. Some scientists believe that it was the sea cucumber, and not the fish, that the first expedition to the bottom of the Challenger Abyss saw.

Modern scientific classification separates 6 units of sea cucumbers from total 1 150 species. They appeared on Earth about 450 million years ago.

Description of holothurians

Sea cucumbers got their name from resemblance with cucumber fruits. They have a soft cylindrical body, elongated in length. But the shape of the body can vary from almost perfect spherical (for example, sea ​​apples — Paracucumaria and Pseudocolochirus), to serpentine (for example, detachment Apodida).

The average body length ranges from 10 to 30 cm. Especially large species grow up to 3 meters long.

The mouth is located at one end of the animal and is quite complex. It is surrounded by 10-30 tentacles that can be drawn inward. These tentacles may be the most various forms- from simple tubular legs to complexly branched and tree-like. The shape of the tentacles depends on the food consumed. In species that prey on planktonic animals, they have a tree-like shape, the main task of which is to maximize the volume of filtered water. Species that feed on the upper benthic substrate have a branched tentacle structure. And species that live on a sandy or muddy bottom have simple short tentacles in the form of blades that make it easier for them to dig the soil.

The so-called ambulacral legs grow along the entire length of the body. They perform several essential functions. First, they perform a tactile function. Secondly, they participate in the respiration of the sea cucumber, transferring fresh water into the animal. Thirdly, helping the animal to move along the bottom. In some species (mostly deep-sea), ambulacral legs are used as simple feet. But most often the muscles of the body are responsible for the movement.

Behavior and lifestyle

Sea cucumbers are found in all oceans in in large numbers populating the seabed. Gathering in large groups they are on a constant journey in search of food. At a depth of more than 9 km. they make up 90% of total mass of the entire fauna (meaning the macrofauna - visible to man naked eye). Holothurians are better than other animals adapted to survival at extreme depths, and even at a depth of 5 km their number and species diversity as rich as near the surface. Only porpoises can compete with sea cucumbers for the title of the most unpretentious deep-sea animal.

The bodies of some species of deep-sea sea cucumbers (for example, Enypniastes eximia and Paelopatides confundens) consist of a special gelatinous tissue with unique properties that provide buoyancy to the animal. This makes it possible to decently swim in the water and move to new habitats. The only "true" pelagic (lives in the water column, not at the bottom) sea cucumber - species Pelagothuria natatrix. Other "floating" holothurians move in this way only from time to time. They are often confused with, but the color of sea cucumbers is brighter, mostly red.

There are also types of sea cucumbers (in the detachment Elasipodida) with a body density almost the same as that of water. Having pushed off from the bottom, they are able to soar in the water column at a distance of more than 1 km. Such holothurians have specific swimming appendages resembling an umbrella or a petal, by rotating which the animal can maneuver while swimming.

But most sea cucumbers are still exclusively bottom and inactive animals. Crawling along the bottom they pick up decaying organic matter and plankton. Also, with the help of oral tentacles and legs, they dig the bottom soil, sometimes completely digging into it. By loosening the bottom and destroying detritus (undecomposed particles of animals and plants), they play a very important and useful role in marine ecosystem. In some regions of the world's oceans, the density of sea cucumbers reaches 40 individuals per 1 m². In one year, such a group of holothurians can process up to 20 kg. soil.

Pushing on the bottom, sea cucumbers do not show any territorial behavior, occupying free place and moving forward when there is no food left in their area. Only during the breeding season, they transmit signals to their relatives with the help of special hormones, completely ignoring them the rest of the time.

Symbiosis with other animals

Some animals can live in symbiosis and commensalism (a way of coexistence of two organisms in which one imposes on the other the regulation of external environment) with sea cucumbers. Most often, together with holothurians, shrimp can be found. There is even a species of shrimp that lives all its life with echinoderms on their body, for example, the species Periclimene imperator.

Separately, it is worth highlighting small fish of the family Carapidae, the so-called pearl fish. These small fish with an elongated body can live at a depth of up to 2,000 m. An interesting strategy for their survival is the ability of fry to literally hide inside the body of a sea cucumber, entering it through the anus or mouth. There it grows, hiding from predators and at the same time finding food in the remnants of food coming out of the sea cucumber. When a fish grows up, it leaves its owner forever.

Many sea ​​worms and crabs also take refuge inside sea cucumbers. Some types of sea cucumbers (for example, Actinopyga) in the process of evolution acquired special teeth in the anus, which do not allow other animals to penetrate them inside.

Defenses and Predators

Sea cucumbers are very easy prey. They cannot escape quickly and are found in great abundance everywhere. But only highly specialized predators specifically hunt holothurians. The body of sea cucumbers contains many toxins (in particular holothurin), because of which they are ignored by most marine life. Purposefully hunting for holothurians is carried out only by large mollusks of the family Tonnidae- so called Barrels that paralyze them with powerful poison before sucking out their soft tissue.

Some species marine fish can eat sea cucumbers if they cannot get other food. Holothurians have been observed to be eaten by triggerfish and tetraodon, as well as some species of crabs, hermit crabs, and lobsters.

To protect themselves, sea cucumbers have developed special agent defenses not found in other animals. When danger arises, they squirt into the water through the anus. poisonous part intestines - Cuvier tubes. Normally, inside an animal, Cuvier's tubes are long threads that swell greatly when they enter the water. In this way, sea cucumbers try to disorientate and confuse predators. Lost pipes, depending on the type, are restored within 1-5 weeks.

The ejection of the Cuvier tubes is accompanied by the ejection toxic poison holothurin into water. This poison forms a thick foamy mass that kills other animals that are nearby.

Significance for a person

There are many commercially important types of sea cucumber used in cooking and traditional Asian medicine. Pharmaceutical companies produce various preparations based on dried golden sea cucumber - gamate. Oils, creams, cosmetics, and medicines are made from it.

In Asia (mainly in China), a wide variety of dishes are prepared from sea cucumber - from salads to hot dishes. Most holothurians are taken from artificial reservoirs, where they have been specially grown for sale since the 1980s. It is noteworthy that in the Chinese market, sea cucumber grown or caught in Alaska is in demand. It has a higher nutritional value and size.

Artificial breeding of holothurians ensures the safety of the state of the populations, but the markets still offer sea cucumbers caught in nature, in particular on coral reefs. In the recent past, such fishing has greatly reduced some species. "Wild" cucumbers are more expensive - they are larger and are considered more delicious. To combat illegal trapping, the government has set a limit on the price per kilogram of meat for all holothurians sold. This made it unprofitable to sell expensive types of sea cucumbers.

Biology

Toxins produced by holothurians are of interest for pharmacology. Fishermen on the islands Pacific Ocean use poisonous Cuvier tubules of some species when fishing.

see also

Literature

• Dolmatov I.Yu., Mashanov V.S. Regeneration in holothurians. - Vladivostok: Dalnauka, 2007. - 208 p.

Links

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See what "holothurians" are in other dictionaries:

Neg. worm-like echinoderms of marine animals found in the Southern Ocean. This includes trepang. Dictionary of foreign words included in the Russian language. Pavlenkov, F., 1907 Detachment of echinoderms ... ... Dictionary of foreign words of the Russian language

holothurians- ii, pl. holothurie f. gr. holothurion 1. Marine animal with a worm-like body. BAS 2. And over there, some small, thick sulfur sticks, like sausages, are stacked in long stacks in rows. These are all holothurians, marine animals, like ... ... Historical dictionary gallicisms of the Russian language

Sea cucumbers (Holothuroidea), a class of echinoderms. Fossil skeletal plates of G. have been known since the Devonian. body b. h. barrel-shaped or worm-shaped (length from several mm to 2 m), many with external. appendages (tentacles, legs, papillae, sail, etc.), ... ... Biological encyclopedic dictionary

- (Holotburioidea), a class of the echinoderm type, differ from other representatives of the same type by a worm-like body, leathery outer covers containing calcareous bodies, the absence of an external madrep plate, a crown for the most part ... ... Encyclopedia of Brockhaus and Efron

- (sea cucumbers), a class of animals such as echinoderms. The body is usually worm-shaped, from a few mm to 2 m. About 1100 species, ubiquitous in the seas and oceans. Bottom, crawling forms. Many, when irritated, are able to throw out the insides or ... ... Modern Encyclopedia

- (sea cucumbers sea capsules), a class of marine invertebrates such as echinoderms. The body is usually worm-shaped, from a few mm to 2 m. Approx. 1100 species, almost everywhere in the seas and oceans. Bottom crawling forms. Some are capable of... Big Encyclopedic Dictionary

- (Holothuroidea) a class of echinoderms with a strongly reduced skeleton, consisting of numerous microscopic calcareous needles decomp. forms. Marine animals belonging to the nekton. Rare in fossil form, found in the form of prints or ... ... Geological Encyclopedia

Sea cucumbers, sea pods (Holothuroidea) Holothurians Cucumeria planci is one of the species of edible trepangs. a class of marine invertebrates such as echinoderms (Echinodermata). They live on the bottom, mainly in shallow water areas, where they usually lie like ... ... Collier Encyclopedia

- (Holothurioidea) a class of the echinoderm type (Echinodermata, see), differ from other representatives of the same type in a worm-like body, leathery outer covers containing calcareous bodies, the absence of an outer madreporous plate, ... ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

Iy; pl. (sing. holothurian, and; f.). [Greek holothurion] Class of marine invertebrates of the echinoderm type; sea ​​cucumbers. * * * Holothurians (sea cucumbers, sea capsules), a class of marine invertebrates such as echinoderms. The body usually... encyclopedic Dictionary

Holothurians, or sea pods, or sea ​​cucumbers(lat. Holothuroidea) - a class of invertebrate animals such as echinoderms. Species eaten are common name"trepang".

The modern fauna is represented by 1150 species, divided into 6 orders, which differ from each other in the shape of tentacles and calcareous ring, as well as the presence of some internal organs. The oldest fossils of holothurians date back to the Silurian period.

Despite the fact that the holothurian is usually called sea ​​cucumber, this is a real animal belonging to a separate class of invertebrates such as echinoderms, like sea ​​urchins, starfish, serpentine - brittle stars and sea lilies.

The ancient Greeks called these unusual marine inhabitants echinoderms, while they were combined either with worms or with intestinal animals. Then such names of this type of animals appeared as radiant, zoophytes, i.e. semi-plants, semi-animals (like sponges), and only at the end of the 19th century they were singled out as an independent and unique type animals under modern name echinoderms.

At present, animals of the echinoderm type are considered by zoologists to be the most highly organized representatives of invertebrates.

They can be found in many seas and oceans, from shallow coastal waters to deep sea trenches(For example, deep sea species present in the genera Paelopatides and Paroriza). The most common sea cucumbers in the waters of the tropics and subtropics, preferring to settle Coral reefs and rocky soils overgrown with dense vegetation.

Holothurians are very ancient animals. The age of some of the fossilized remains that fell into the hands of specialists was estimated at 450 or even more million years. According to scientists, these animals appeared in the Cambrian period, that is, at least 500 million years ago.

Holothurians- absolutely unique animals. Like starfish, urchins and brittle stars, they have a pronounced five-ray body symmetry, and move along the bottom on tiny tube legs, setting them in motion, pumping water through the channels of these tubes.

But there are also significant differences in the body structure and appearance of holothurians and other echinoderms. They have an elongated body, resembling either a cucumber or an oblong spheroid, and sometimes a short worm. There are no pronounced rays or long needles on the body of these animals.

Their skeletal lattice is represented by small calcareous formations in the form of blunt needles - spicules, occurring in the walls of the body. The spines of some species are sharp and hard, you can even get hurt on them.

If you touch the skin of the holothurian with your hand, it will seem wrinkled and rough to the touch. The body is elastic, muscular, since five ribbons of longitudinal muscles are radially located in it, stretching from the mouth to the anus.

Around the mouth is a corolla of short tentacles, with which the holothurian captures prey and pulls it into the mouth. The tentacles are not capable of significant contractions, since they are not equipped with the appropriate muscles for this.

The esophagus of sea cucumbers has the appearance of a spirally wrapped intestine surrounded by a calcareous ring, which serves as a support for the longitudinal muscles.

Holothurians reproduce by eggs. Individuals have a sexual difference (males and females), but outwardly they are difficult to distinguish. Fertilization of eggs is most often external, but there are also species in which the offspring develops in the body of the female. Holothurians live on average 5-10 years.

Body coloration of holothurians different types may be brown, brown-red ( different shades), green, yellowish green, and even black or white. There is information that there are also blue holothurians, to which popular rumor ascribes numerous medicinal healing properties bordering on the miraculous. Perhaps such albinos are found in nature, but the healing properties of their color are probably just a beautiful legend. The color of the body of holothurians largely depends on the habitat - it has been noticed that the skin color of these animals tends to harmonize with the color of the underwater landscape.

Body sizes in holothurians of different species can vary from a few centimeters to five meters (the record holder is the spotted synapta Synapta maculata), but most often individuals are from 30 cm to a meter long.

The way of life of sea cucumbers is inactive - they usually slowly crawl along the bottom, filtering edible particles of organic matter from the soil. It is curious that at the same time they are located on their side, since the ambulacral legs that serve them for movement are located on the side of the body. These primitive animals feed on small living organisms - benthos, i.e. plankton, which lives in the bottom layers of water. But the basis of the diet of holothurians is the organic remains of dead organisms, constantly sinking to the bottom from different depths strata sea ​​waters. For this reason, holothurians are called orderlies of the sea, and indeed, their role in cleaning the seabed from microscopic carrion can hardly be overestimated.

These animals have another amazing ability- they can turn their stomach out through the cloaca and throw out its contents, sometimes even with internal organs. This method of holothuria is often used in moments of danger, when it is necessary to escape from the enemy. Since holothurians move more slowly than turtles on their short legs, they have to sacrifice their entrails to divert the predator's attention.
BUT unique abilities holothurians to regenerate body parts and even internal organs help them recover the loss in just two to three weeks. As they say - lizards are resting.

To natural enemies holothurians include starfish, some types of molluscs, predatory fish and crustaceans, which are indifferent to the toxins produced by sea cucumbers.

The poisonous filling of the stomach of many holothurians makes it difficult to keep them in aquariums - they can kill not only other pets of an artificial reservoir, but also die themselves in a cloud of toxin. For this reason, it is not recommended for inexperienced amateurs to settle holothurians in their aquarium.

Among these animals there are edible species, which are called trepangs (for example, many representatives of the genera Holothuria, Bohadschia, Actinopyga, Microthele, etc.).
Trepangs are eaten by many Asian peoples (Japanese, Chinese, Malays, etc.) - they are caught by commercial methods and brought to the table in dried, smoked, boiled, fried or canned form. There are even dishes made from raw sea cucumbers.

Holothuroidea Blainville, 1834

The modern fauna is represented by 1150 species, divided into 6 orders, which differ from each other in the shape of tentacles and calcareous ring, as well as the presence of some internal organs. About 100 species are found in Russia. The oldest fossils of holothurians are from the Silurian period.

Holothurians are relatives of starfish and hedgehogs.

Biology

Unlike other echinoderms, holothurians lie “on their sides” at the bottom, while the side bearing three rows of ambulacral legs ( trivium) is ventral, and the side with two rows of ambulacral legs ( bivium) dorsal. In deep-sea holothurians, the ambulacral legs can be greatly elongated and used as stilts. Some species move due to peristaltic contractions of the muscles of the body wall, pushing off the ground with protruding calcareous bones.

Most holothurians are black, brown or greenish in color. Body length varies from 3 cm to 1-2 meters, although one species ( Synapta maculata) reaches 5 m.

Lifestyle and nutrition

Holothurians are sedentary or crawling animals found in almost any part of the ocean - from the coastal strip to deep-water depressions; most numerous in tropical coral reef environments. Most species are bottom-dwelling, but there are also pelagic ones. Usually they lie "on their side", raising the anterior, oral end. Holothurians feed on plankton and organic residues extracted from bottom silt and sand, which is passed through the digestive canal. Other species filter food from the bottom waters with tentacles covered with sticky mucus.

With strong irritation, the back of the intestine is thrown out through the anus along with the water lungs, scaring away or distracting the attackers; lost organs are quickly restored. In some species, Cuvier tubules containing toxins are also ejected. Holothurians are preyed upon by starfish, gastropods, fish and crustaceans. In the water lungs of some species, fish settle - fieraspheres ( fierasfer), sometimes pea crabs ( Pinnotheres).

Reproduction and development

Life expectancy - from 5 to 10 years.

Economic importance

Some species of holothurians, especially from the genera Stychopus and Cucumaria, are eaten under the name "trepangs". In China and the countries of Southeast Asia, they are considered a delicacy, served fresh or dried with fish and vegetables. Their fishing is most developed off the coast.