Starfish: photos, types of stars, descriptions. The most beautiful starfish in the world

Starfish - animals with unusual shape bodies, thanks to which they attracted the attention of people back in ancient times. Starfish belong to the phylum Echinodermata, in which they are classified as a separate class, numbering almost 1,600 species. The closest relatives of these invertebrates are brittle stars, or snaketails, which are very similar to them, and more distant relatives are sea cucumbers and sea urchins.

Home distinguishing feature starfish is, of course, a body shape. In general, the body of starfish can be divided into a central part - the disk, and lateral outgrowths, which are usually called rays or arms. These animals are characterized by radial symmetry, so their body is divided into symmetrical sectors, the number of which is usually five. However, among starfish there are organisms with a large number axes of symmetry: in some species their number can reach 6-12 and even 45-50.

Nine-armed starfish (Solaster endeca).

Each sector, accordingly, includes part of the central disk and a hand. It would seem that such a similar structure should result in the monotony of these living organisms. But the body shape of starfish is very variable. Firstly, the relative length and thickness of the rays varies greatly: in some species they are elongated and thin, in others they have a triangular shape, sharply tapering towards the end, in others the rays are so short that they practically do not protrude beyond the edges of the central disk. The latter type of stars have a very high central disk, so they resemble pillows. Thus, in most species of sea stars, the length of the rays is 3-5 times greater than the diameter of the central disk, in the longest-armed ones it is 20-30 times, and in the cushion-shaped ones it tends to zero.

This colorful ottoman on the seabed is actually the New Guinea starfish (Culcita novaeguineae).

Secondly, starfish differ in surface texture and color. Here the variety simply defies description - smooth, spiky, prickly, rough, velvety, mosaic; monochrome and patterned, bright and faded. The color range of these animals includes almost all colors, but most often there are various shades of red, less often blue, brown, pink, purple, yellow, and black. Pale sea stars usually live in the depths, while shallow-water species are brightly colored.

This is the same New Guinea kulzita, but of a different color.

At first glance, starfish seem primitive, because they do not have any noticeable sensory organs, a brain, and are poorly differentiated internal organs, but this simplicity is deceptive.

The Linkia starfish (Linckia laevigata) is bright blue in color and has sausage-like rays.

First of all, it should be noted that starfish have internal skeleton. They do not have a backbone or individual bones, but have many calcareous plates connected to each other in an openwork system.

Openwork plexuses of skeletal elements on the surface of a starfish.

In a young sea star, the skeletal elements are hidden under the skin, but over time the skin over some calcareous spines wears off and they become visible from the outside. It is these spines that give starfish their spiny appearance.

The spines on the surface of the starfish are covered with skin, but some of them are already exposed and have a shiny surface.

In addition, on the upper side of the body in many species, calcareous plates may be visible, fused together or forming a network.

A bizarre pattern formed by the skin and skeletal elements of a starfish.

Finally, the third element influencing appearance starfish are pedicellaria. Pedicellariae are modified needles that look like tiny tweezers. They play an important role in the life of a starfish; with their help, it cleans the upper side of its body from debris and sand. All skeletal elements are connected to each other by muscles, so after the death of a starfish, its skeleton crumbles into calcareous plates and not a trace remains of the animal.

Acantaster starfish, or crown of thorns(Acanthaster ellisii) has spiny and poisonous spines.

The muscular system of starfish is relatively poorly developed. Each ray has a muscle cord that can bend the ray upward, and this, in fact, limits the muscle movements of the stars. But mobility is not limited at all. Starfish can crawl, dig, bend, and swim, but they do not do this with the help of muscles.

Scalloped sea stars (Patiria pectinifera) climb on the seaweed.

These animals have special system body - ambulacral. Essentially, this system consists of channels and cavities connected together and filled with liquid. The starfish can pump this fluid from one part of the system to another, causing its body parts to flex and move. The central part of this system is the ambulacral legs - tiny blind outgrowths of the ambulacral canals on the underside of the starfish. Each leg moves independently of the others, but their actions are always coordinated. With the help of these microscopic elements, the starfish is able to perform miracles. For example, it is able to climb a vertical surface, can stick to the glass of an aquarium for a long time, can rear up, swelling up like an angry cat, or maybe, grabbing hold of two rays, push the valves of a mollusk shell apart. And all this is done by an animal practically devoid of a brain and eyes!

Translucent ambulacral legs are visible on the underside of the beam.

To be fair, it is worth noting that starfish do have some sense organs. These are the eyes located at the ends of each ray. The eyes are very primitive and distinguish only light and darkness; starfish cannot see objects. Starfish are capable of catching chemicals(analogous to smell), only they feel them differently. Some species are very sensitive and can crawl to the bait for several days in a row by smell, others can crawl past the victim a couple of centimeters and not smell it. Sea stars have a very developed sense of touch; they try to get rid of the sand that covers them from above, and also always try to feel their way with the help of small tentacles at the end of each ray. The sense of touch tells the starfish whether it is a victim or a predator. The starfish's brain is replaced by a group of loosely interconnected cells. What is surprising is that despite such a primitive structure nervous system starfish can produce elementary conditioned reflexes. For example, starfish that were often caught in nets began to get out of them faster than those that were caught for the first time.

At the end of the ray of the asterodiscus starfish (Asterodiscus truncatus) a formed eye is visible. The beam itself is covered with relief limestone plates.

Another “strong” system, in the literal and figurative sense of the word, of starfish is the digestive system. The mouth of these animals is located in the center of the disc on the underside, and the tiny anus is located on the dorsal side of the body. By the way, starfish rarely use it (in some species it even becomes overgrown), preferring to remove food debris through the mouth. The stomach of starfish has projections extending into rays; reserves are deposited in these projections nutrients in case of hunger. And starfish regularly starve because they stop feeding during reproduction. The stomach in many species can turn outward through the mouth opening, and it stretches like rubber, taking any shape. Thanks to its expandable stomach, the starfish can digest prey that is larger than itself. There is a known case when the starfish Luidia swallowed such a large sea urchin that it died, unable to spit out its remains.

A tiny anal opening is visible in the middle of the central disc of Phromia monilis.

Other body systems are poorly developed in starfish. They breathe through special skin outgrowths on the upper side of the body, washed by sea currents. They do not have gills or lungs, so starfish are sensitive to lack of oxygen. They also cannot tolerate desalination of water, so they are found only in seas and oceans. The size of sea stars ranges from 1-1.5 cm for the miniature spherical star Podosferaster to 80-90 cm for the sea star Freyella.

The name of this starfish speaks for itself - elegant fromia (Fromia elegans).

Starfish have a global distribution. They are found everywhere in all seas and oceans from the tropics to the poles. Of course, in warm waters species diversity is higher than in cold ones. Most species prefer to live in shallow waters, some even end up on the shore during low tides. But among these animals there are also deep sea species, including those that live at depths of over 9 km!

Starfish in shallow water.

Starfish crawl along the bottom most of the time, they do it very slowly, the usual speed of an average-sized starfish is 10 cm per minute, but a starfish can “hurry up” at a speed of 25-30 cm per minute. If necessary, starfish can climb onto rocks, corals, and algae. If a starfish falls on its back, it immediately turns over with its ventral side down. To do this, the animal bends two rays so that the ambulacral legs on the lower side touch the ground, and then the starfish turns its body and takes its usual position. Some species are even capable of swimming awkwardly over short distances. Starfish can be called sedentary animals; tagging of animals has shown that they do not move more than 500 m from the place of initial catch.

The coriaster starfish (Coriaster granulatus) looks like a bun.

Despite their outward primitiveness and apparent helplessness, starfish formidable predators. They are quite voracious and never refuse prey, with the exception of the period of gestation. Only deep-sea species feed on silt, from which they extract food particles; kulcite sea stars, which prefer to eat fouling on corals, can also be called conditionally “non-predatory”. All other species actively hunt other animals.

Not at all romantic relationship developed between the sea star Solaster dawsoni and Hippasteria spinosa.

Most starfish are picky; they eat everything they can hold with their hands and whatever their “rubber” stomach can reach, not disdaining carrion. Some species can only feed on a certain type of food: sponges, corals, gastropods.

The pretty starfish (Pentagonaster pulchellus), also called the biscuit starfish for its biscuit-like body shape.

The favorite prey of sea stars are sedentary animals like themselves - sea urchins and bivalves. The star catches the sea urchin by crawling and eats it with its mouth. Bivalves They have shells whose valves close tightly in case of danger, so starfish treat them differently. First, the starfish sticks with two rays to the shell flaps, and then begins to move them apart. It must be said that the ambulacral legs are firmly glued to the substrate thanks to an adhesive lubricant, and one single ambulacral leg can develop a force of up to 30 g! And on each ray of the starfish there are hundreds of them, so the star, like a real strongman, pushes the shells apart with a force of several kilograms. However, the starfish does not need to spread the shell flaps to their full width; hearty lunch a gap of 0.1 mm is enough for her! The starfish turns its stomach into this truly microscopic gap (it can stretch up to 10 cm) and digests the mollusk in its own home.

Asteria starfish (Asterias rubens) reaches out to a clam.

Most starfish are dioecious; very few species have both male and female gonads. The gonads are located in pairs at the base of each ray. In the asterine starfish, the young are first male and then change to female. A special exception is the ophidiaster starfish, which has... no males at all. Females of this species lay eggs without fertilization, such reproduction is called parthenogenesis. During mating, males and females connect their rays and release sperm and eggs into the water. The number of eggs depends on the type of development of the larvae and ranges from 200 in those species that bear offspring, and up to 2-200 million in species with free-swimming larvae.

Mating starfish.

There are three types of starfish larvae. In some species, the eggs hatch into a free-swimming larva, which feeds on microscopic algae, and then attaches to the bottom and gradually turns into a small star. In others, the free-swimming larva has large reserves of yolk, so it does not feed and immediately turns into an adult form. In starfish that live in cold waters, the larvae do not separate from the mother’s body at all, but accumulate near her mouth or even in special stomach pockets. During this period, the caring female rests only on the tips of the rays, and arches her body into a dome, under which the larvae are located. Since the larvae are located near the mouth opening, the female does not feed during this period. The larval form is the most mobile in life cycle starfish, it is during this period that the larvae can be carried by currents over very long distances.

The starfish larva has bilateral symmetry.

In addition to sexual reproduction, starfish can also reproduce asexually. Most often this occurs in multi-rayed species; the body of the animal is divided into two halves, each of which builds up the missing rays. In other species, asexual reproduction may be the result of regeneration following traumatic damage to the body. If starfish artificially divided into several parts, then a new organism will be formed from each. Even one beam is enough for restoration, but a piece of the central disk is required. Starfish grow slowly, so they look lopsided for many months.

A seagull caught a starfish.

But the starfish Astropectenus is friends with polychaete worms. One star can have up to five cohabitants who prefer to stay on the underside of the body, close to the star’s mouth. The worms pick up the remains of the star's prey and even... stick their heads into its stomach. Ctenophores live on the echinaster starfish special type, which clean the surface of the star from fouling.

These bright spots on the Luzon starfish (Echinaster luzonicus) are ctenophores (Coeloplana astericola).

Since ancient times, people have paid attention to the colorful animals of shallow waters, but starfish were of no economic interest to them. Only in China are starfish sometimes eaten, while attempts to feed starfish to domestic animals can lead to the death of the latter. This is likely due to toxins that some species accumulate by eating coral and poisonous shellfish. But with the development of the maritime economy, people began to classify starfish as their enemies. It turned out that starfish often eat bait in bottom traps for crabs, and also raid plantations for breeding oysters and scallops. In a few years (that’s how long it takes to grow oysters), starfish can destroy an entire oyster bank. At one time they tried to destroy starfish by cutting them into pieces, but this only increased their numbers, because from each stump a new starfish grew. Then they learned to extract starfish with special trawls and kill them with boiling water.

A very impressive mosaic starfish (Iconaster longimanus).

The worst pest was the acanthaster starfish, or crown of thorns. This very large starfish feeds exclusively on corals, leaving a crown of thorns behind. coral reef just a white lifeless path. At one time, these stars multiplied so much that they literally destroyed a huge section of the Great Barrier Reef off the coast of Australia. The unique geological formation was under threat of destruction. The fight against the crown of thorns was complicated by the fact that its thorns are poisonous to humans; the prick of the crown of thorns causes burning pain, although it is not fatal. Specially trained divers collected acanthasters with sharp peaks into bags or inserted them into the body of a starfish lethal dose formaldehyde. Only in this way was it possible to pacify the invasion of voracious predators and save the reef. Nowadays, all species of starfish are in a safe condition and do not need protection.

The crown of thorns eats the coral.

Mysterious animal - Starfish. First of all, STAR. Where else can you find such a natural configuration? Secondly, for some reason it initially seemed to me that it was some kind of algae or coral. Look at the diversity and beauty of these stars! However, look further at the video about how they feed :)

(Total 28 photos)

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1. Starfish are veterans of the seabed; they appeared more than 450 million years ago, ahead of many forms of modern inhabitants of the underwater depths.

2. They belong to the class Echinodermata, being relatives sea ​​cucumbers, brittle stars, sea lilies, sea cucumbers, sea urchins - currently there are about 1,600 species with a star-shaped or pentagonal shape.

4. The starfish, despite its inactivity and the absence of a head as such, has a well-developed nervous and digestive system. Why, exactly, “echinoderms”? It's all about the hard skin of the starfish - on the outside it is covered with short needles or spines. Conventionally, these bizarre creatures can be divided into three groups: ordinary starfish; feather stars, named for their writhing rays (up to 50!), and “fragile” stars that cast off their rays in case of danger.

5. True, it will not be difficult for this animal to grow new ones, and new stars will soon appear from each ray. How is this possible? - Thanks to characteristic feature the structure of the star - each of its rays is structured identically, and contains: two digestive outgrowths of the stomach, performing the function of the liver, a red eyespot at the tip of the ray, protected by a ring of needles, radial bundles of nerves, olfactory organs (they are also suckers and a method of movement), located in a groove on on the ventral side of the papules - skin gills in the form of thin short villi, located on the back and producing gas exchange processes of the genital organs (usually two gonads on each ray); a skeleton consisting of a longitudinal row of vertebrae inside, and hundreds of calcareous plates with spines covering the skin and connected muscles, which not only protects the animal from damage, but also makes its rays very flexible. The bodies of starfish are 80% calcium carbonate.

6. Thus, each ray of a starfish, once separated from its body, is completely viable and quickly regenerates. Well, connected together, the rays form closed systems in the center of the animal: digestive system passes into the stomach from two sections and opens with a button-shaped disc that serves as the mouth; bundles of nerves unite into a nerve ring. The main system of the starfish, which we deliberately left “for dessert,” is the ambulacral system. This is the name given to the water-vascular system, which serves the echinoderm simultaneously for respiration, excretion, touch and movement, together with the muscles providing musculoskeletal function. Canals extend from the perioral ring into each ray, from which, in turn, lateral branches lead to hundreds of cylindrical tubes on the surface of the body - ambulacral legs containing special ampoules and ending with suction cups. An opening on the back, called the mandreoporous plate, serves to connect this system to the external aquatic environment.

7. So how does the ambulacral system work? – It is filled with water under slight pressure, which, entering through the mandreoporous plate into the perioral canal, is divided into five ray channels and fills the ampoules at the base of the legs. Their compression, in turn, fills the legs with water and stretches them. In this case, the suckers of the legs attach to various objects of the seabed - and then sharply contract - the ambulacral legs are shortened, and thus the body of the animal moves in smooth jerks.

8. Starfish are voracious predators, although there are exceptions in the form of herbivorous species that feed on algae and plankton. In general, the favorite delicacies of these animals are clams, mussels, oysters, scallops, littorinas, barnacles, reef-building corals and various invertebrates. The star finds prey by smell. Having discovered a mollusk, it attaches itself with two rays to one shell valve, and the remaining three to the other valve, and a many-hour struggle begins, which the starfish always wins. When the mollusk gets tired and the doors of its home become pliable, the predator opens them and literally throws its stomach on the victim, turning it out! By the way, food digestion occurs outside the animal’s body. Some starfish are even capable of digging out prey hiding in the sand.

9. As for reproduction, most starfish are divided into males and females. Fertilization occurs in water, after which free-swimming larvae called brachiolaria are formed. Unlike adult individuals, their structure is subject to the laws of symmetry, and includes a ciliary cord necessary for collecting food particles (exclusively unicellular planktonic algae), a stomach, esophagus and hind intestine. Usually the larvae swim near an adult sea star of the same species - and after several weeks, under the influence of its pheromones, they undergo metamorphosis: having fixed themselves on the bottom, they turn into tiny (0.5 mm in diameter), but already five-linked starfish. But these babies will be able to give birth only after two or three years. If the larvae serve as species dispersers and drift long distances, they are able to delay their transformation into adults and not settle to the bottom for several months - and they can grow up to nine cm in length. Among the starfish there are also hermaphrodites - they carry their young in a special brood pouch or cavities on their backs.

10. Taking into account the large number of starfish, it is clear that they also influence the growth of populations of species that are hunted. Nobody risks hunting them, since their bodies contain extremely toxic substances– asteriosaponins. Being virtually invulnerable, starfish are at the top of the marine food pyramid and can therefore have a lifespan of up to 30 years. According to scientists, these brightly colored legendary inhabitants of the seas also make a significant contribution to the recycling process carbon dioxide, produced including by the industrial facilities of the planet - their share is about 2% CO2, that is, more than 0.1 gigatons of carbon per year, which, you see, is not at all weak for such seemingly small creatures!

Starfish- These are very unusual animals that live in the seas and oceans. They are invertebrates, belong to the phylum echinoderms and are very similar to stars, as they have rays diverging into different sides. Most often, the sea star has five rays, but there are species with three, four and six rays. The color of the body is often very bright and varied; on the surface there are special hard plates with needles or spines. The sizes of stars vary greatly and can range from 2 cm to 100 cm, but most stars have a diameter of about 20 cm.

Spreading

Starfish are widely distributed across to the globe. They can be found in all oceans and seas and in all climatic zones, but in warm waters there are more starfish than in cold waters, and in fresh waters they are not found at all.

These animals prefer a bottom lifestyle, often live in shallow water, but can also live at depth, but not deeper than 8.5 km.

Now on earth there are 1.6 thousand species of starfish.

Nutrition

Almost all starfish are predators. They mainly feed on marine invertebrates - worms, mollusks, sponges, barnacles, corals and others. Some deep-sea starfish feed on the mud they find on the bottom.

The digestive system of starfish is quite unique. Their mouth opening is located on the ventral side, and two stomachs extend from it. One stomach has the ability to turn outward and envelop the victim, and the second stomach has ten processes that are located inside the rays of the starfish. This unusual digestive system allows the star to eat prey that is larger than itself.

Lifestyle

Starfish are slow, sedentary animals. They usually crawl lazily along the bottom, lie still, or may climb rocks and corals in search of prey. Their movement speed is very low - 10-30 cm per minute. Stars are considered animals leading sedentary image life. As a rule, they move no further than 0.5 km from their usual place of residence.

In their development, stars go through several stages of development. From the eggs that adults throw into the water, larvae are first formed and then they gradually turn into an adult starfish. Some species of starfish carry larvae in special brood pouches on their bodies.

Starfish can live 20 years or more.

• Starfish don't have a brain.
• Instead of eyes, starfish have light-sensitive cells located at the tips of their rays.
• Starfish are capable of regeneration - from a detached ray, a new star can develop.

Brief information about starfish.

When you see a starfish for the first time, the first thing that comes to your mind is that it’s an ordinary souvenir, but in fact it’s living creature, which looks like a star. With its way of life, this entity seems to ignore all the usual laws of biology - having neither blood nor brain, stars have unique eyes and can digest food outside their body.

External features of starfish

Starfish are invertebrate, nearly symmetrical animals that are found in all oceans. They appeared approximately 500 million years ago. Most of the representatives of this species are found not at the bottom, but almost on the surface, but there are stars that are found at a depth of 6000 meters. Today, zoology describes more than 1,800 species of starfish. Each species has its own characteristics, but all representatives are united by the correct symmetrical shape and row external features, which prevents them from being confused with any other species.

Typically, stars have five or six rays that emanate from the center of the disk. The record number of rays that zoologists recorded is 50; at great depths, representatives of the species with 10-15 rays are found. In starfish, the body length can reach one meter, but the most characteristic size is 15-25 centimeters. Large stars can weigh 5 kilograms; they are also called “solar stars”. These types of animals are more powerful; they have enough power to tear apart the shells of crustaceans. They hunt their prey and can even long time chase.

Starfish have a rough or smooth surface and may be covered with ridges or sharp, poisonous spines. Some of the representatives of the starfish family have very bright colors and are extremely beautiful; it is impossible not to notice their presence in the water. The color range of starfish includes all shades and colors. Bright stars They live close to the surface, while pale ones, as a rule, live at great depths.

Feeding starfish

As for the nutrition of starfish, their diet is quite varied - they do not hesitate to feast on carrion, they eat sea ​​urchins, which is several times larger than them, and crabs can even attack small fish. Moving along the bottom, they dig small holes and there they wait for their prey, which inadvertently approaches the mouth opening of the star. The feeding process itself is very interesting: the star drags its stomach out and envelops its victim in it. During the eating process, special enzymes are released that help digest food not inside the star, but outside.

Starfish have a very flexible stomach; it only needs 0.1 mm to penetrate the gap. It is for this reason that mollusks only need to open their valves a little, and the starfish will already envelop them with its stomach and eat it. The eating process can last up to 8 hours, everything happens very slowly, but in general the feeding time depends on the size of the victim. In the industry, the starfish is considered the real enemy of oysters due to the reasons described above. In order to limit the contact of starfish with oysters, they are systematically removed using nets.

Regenerative abilities and reproduction

In many scientific videos, the starfish regrows lost organs and is completely restored if at least half of the disk or lost ray is present. There are scientific cases where a fallen limb completely restored the entire disc. There are also species of starfish that reproduce this way - by fission.

Also present in the species sexual reproduction. Males and females release their eggs into the water and fertilization occurs outside the body. No matter how strange it may sound, one female starfish can become the mother of two million larvae. After fertilization, the larvae mix with ordinary plankton, but when they mature, they settle to the bottom and lead an independent life. Some species of stars hatch larvae in their stomach or under a plate. But, this is rare; in most cases, fertilization occurs outside the female’s body.

Internal skeleton and muscles

Initially, it may seem that in the absence of olfactory organs and a brain, these are primitive animals, but such simplicity is very deceptive. As the scientific video shows, starfish have a skeleton. Of course, skeleton stars do not consist of a backbone, but they have calcareous plates connected to each other in an openwork system.

In young organisms this openwork system is not visible, but with age skin are erased, and the skeleton begins to emerge. It is the protrusion of the skeletal plates that makes the starfish spiny. Some calcareous plates that protrude outward merge together and create the appearance of tentacles. With their help, starfish clean the outer part of their plate from sand and various garbage. After a starfish dies, its skeleton crumbles and all that remains is dust. Some sea stars have poisonous tentacles and serve as an additional means of hunting small fish and crustaceans.

Regarding muscular system, then, as the scientific video shows, starfish can move, swim, bend, but all this is not with the help of muscles. They are very weak in this species of animal. All the muscle can do is lift the beam upward.

Some of the starfish can even climb up the algae; such movement is achieved thanks to the ambulacral system of the body. The system consists of cavities and channels that are filled with liquid, which the star can distill into different parts of its body and thus move. Main feature This system is that it provides small legs on the underside of the star plane. The tiny outgrowths move individually, but in most cases all movements are coordinated and rhythmic. Thanks to these small legs, the starfish can rear up, stick to vertical planes, and even tear the shell of a mollusk with two rays.

Sense organs of starfish

Starfish completely lack all sense organs, except for the eyes, of course. The eyes are located at the tip of each ray. Starfish do not distinguish objects and colors; their eyes are very primitive, so they only recognize light and darkness.

An analogue of the sense of smell in these animals is the ability to capture chemical substances that are present in the water with their body. Animals move not using their eyes, but using their sense of touch. They feel their way in the sand, and with the help of the same sense of touch, they understand who they encountered on the road, a predator or prey. Note that all this happens in the absence of a brain. Starfish have brains that are tightly connected to each other nerve cells. It is very surprising that in the absence of a nervous system, as the scientific video shows, starfish are still capable of conditioned reflexes. For example, individuals that have repeatedly been caught in nets are freed much faster than those that have gotten there for the first time.

Distribution area of ​​starfish

Starfish can't stand fresh water, therefore they are found only in seas and oceans, where salt water. They move very slowly, on average 10 centimeters per minute. They can climb rocks, seaweed and coral. A very interesting fact is that, unlike turtles, which, having fallen on their backs, cannot turn over on their own, starfish immediately return to their usual position.

This species of animal can be safely classified as sedentary; during its entire life, it is unlikely that it moves further than 500 meters from its birth. In the midst of his habitual habitat, starfish have practically no enemies. The spiny structure of the body is intimidating large predators, so they lead a completely quiet life, but can sometimes be caught in the mouths of seagulls and sea otters, who mistake them for fish.

Vibrant inhabitants depths of the sea, people have noticed for a long time, but starfish do not have any economic use, only in China they are occasionally eaten. Starfish are very sensitive to high temperatures, and you can kill them simply by pouring boiling water on them. Many starfish are poisonous, so it is not recommended to pick them up with bare hands. This once again proves how changeable nature can be - such a beautiful and at first glance harmless creature can deprive big man life in one minute.

These and other inhabitants underwater world you can even see it in person!

What do you know about starfish? Beautiful and unusual creatures, with many interesting facts from their life - in our selection. Currently, about two thousand species of starfish are known.

Starfish do not have a brain or blood - to obtain nutrients, oxygen and other important fluids, the starfish pumps through its body sea ​​water. It is the resulting water that is distributed throughout the body and forms the “water-vascular system.”

On each arm of a starfish, mistaken for tentacles, there are about 15 thousand tiny suckers that help the starfish move.

A starfish is not a fish, but an invertebrate animal.
Starfish are true predators. They are capable of attacking their own kind and can easily feast on the small offspring of their own species, i.e. are cannibals.

Stars have two stomachs, one of which they can even push out to digest shellfish.

Starfish are long-lived, some species live up to 30-35 years.

Many of the starfish are very dangerous. For example, the crown-of-thorns starfish, which is distributed throughout the Indo-Pacific Ocean, is covered in venomous spines. Growing to almost half a meter in length, these creatures become dangerous not only for coral reefs, but also for divers and swimmers.

Starfish can easily change gender and then switch back. True, for such “transformations” several suitable conditions are needed - water quality, temperature and food availability.

Starfish have eyes - exactly as many as there are rays; at the tip of the rays there is an eye, which looks like a red spot. They don’t see very well, of course, but at least they can distinguish between darkness and light.

Even though starfish live underwater, they do not have gills.

Although the appearance of most starfish corresponds to their name, sometimes unusual individuals with bizarre shapes are found. For example, starfish may have a sun-shaped shape, multiple rays, or their shape may be rounded.

The heart of starfish beats at a frequency of 5-7 beats per minute.

The largest starfish can reach 1 meter in diameter and their weight can reach 5 kilograms. solar stars more active than their relatives, and are able to quickly pursue their prey, and, having incredible strength, simply tear the shell of mollusks and crustaceans.

The feeding method that allows the starfish to eat prey much larger than the mouth opening is as follows - since the starfish's mouth is on the underside of its body, the star, having grabbed the prey, wraps its strong hands around it, and then with a strong push he places it under himself, and then pushes it into the stomach.

They are also some of the most ancient inhabitants of the Earth. Starfish about 250 million years.

Stars move using hundreds of tubes that are attached to the surface and then move in waves.

Starfish live at various depths, up to ten kilometers

In the last few years, starfish have begun to actively reproduce. This creates a problem because each individual has an excessive appetite and consumes about 6 square meters corals per year. In some areas, measures are being taken to destroy stars.

However, starfish still bring much more useful than harmful - they are important consumers of carbon dioxide - every year sea stars in total destroy about 2% of the Earth's carbon dioxide, and this is extremely big number within the entire planet.

Another useful role of starfish is to clean the seabed of carrion, weak and sick creatures of the seabed, as well as the remains of dead oceanic organisms.

Starfish go through five stages of growth before becoming adults - during the first month, stars are free-swimming and jellyfish-like, they are small, almost invisible to the eye and tiny plants and animals of the ocean.

Although most sea stars are not poisonous, a large star called the acanthaster or crown of thorns is dangerous to humans. The pricks of its needles bring burning pain to a person - if the needle gets stuck in the skin, then it breaks off from the star’s body and begins to infect the person’s blood with poisonous secretions.

An interesting fact is that if you cut off one of the arms of a starfish or all of them at once, without damaging the central part of the body, they will gradually grow back.