Program “I love Psychology” 

The meaning of stingrays in nature. Stingrays. Sea rays: types

The report about stingrays, summarized in this article, will tell you a lot useful information about this animal.

Message about stingrays

Stingray is a marine cartilaginous fish, which differs from others in the presence of electrical paired organs. The stingray order includes 4 families and 60 species of fish.

Description and characteristics of the electric ramp

The body of the fish is disc-shaped, which is slightly elongated at the end in the form of a tail. It has a tail fin and one or two upper fins. The body of the stingray can reach up to 50 cm in size. But in nature there are more major representatives, whose body length can reach 1.2 m and weigh 100 kg.

Stingray is a sea fish and it has different colors: from a discreet simple color to a bright color with motley patterns and patterns on the body. It is noteworthy that their eyes are located on top, so this type of fish has relatively poor vision. The disc-shaped body is equipped with kidney-shaped organs on the sides that are capable of generating electricity. They are located between the pectoral fins and the head. These organs are designed for catching prey and self-defense. With their help, electric rays release electric beam-like discharges with a power of up to 220 volts and hit their prey.

Where do stingrays live?

Stingrays live on reefs, in areas of sandy beaches, and clay bays. Sometimes they can settle in the depths of oceans and seas. The maximum habitat depth is 1000 m. The fish prefers to live in the waters of tropical and temperate climate zones.

From birth, baby stingrays can already produce electric charge. One female can give birth to 8 – 14 babies.

In addition to electrical abilities, these fish have another talent: they are excellent swimmers. Thanks to their rounded fins, they seem to float in the water and overcome long distances with special efforts.

What do stingrays eat?

The electric stingray feeds mainly on carrion and fish. Small-sized species of stingrays feed on small sea ​​plankton: fish, octopus, crabs. Large species They eat capelin, salmon, sardines, and mullet. In pursuit of prey, the stingray spreads its fins. Having caught up with her, he hugs the victim with his fins and uses an electric discharge.

Stingrays: interesting facts

  • IN Ancient Greece electric stingray was used as a painkiller during operations. They became the prototype for the emergence of modern medical electrical devices.
  • The most dangerous creature in the World Ocean - stingray. It has a 15 cm spike in its tail. The fish makes a laceration that is incompatible with life.
  • The Manta Ray can leap from water up to 3 meters high.
  • The female Sea Devil carries only one baby throughout the year. At birth he weighs 10 kg.
  • The only species of stingray that lives in Ukraine is the Sea Cat. It's poisonous. But its meat is still considered a delicacy. Stingray liver contains a lot of vitamin D.
  • In ancient times, the spines of tail-shaped species of stingrays were used by the tribes of the Pacific Basin as a tip for spears and arrows. They were saturated with poison and were deadly weapons.
  • The sawfish ray is considered the oldest fossil Mesozoic era. Catching them is strictly prohibited. Even in ancient times, it was revered by Asian peoples and the Aztecs.

We hope that the report about stingrays helped you prepare for the lesson. You can leave your story about stingrays using the comment form below.

Stingrays are related to sharks. First, What they have in common is that both do not have bones, they are replaced by cartilage. Second, they live in the depths of the sea. Third, that's what they drive predatory image life.


The habitats of stingrays, as well as sharks, are different latitudes and depths of the seas.

Stingrays look quite peculiar; at first glance, they resemble a children's toy - kite. They have a flattened body, as if pressed down by someone from above. The body of stingrays is covered with scales, the appearance of which resembles thorns. The structure of these spines is similar to the structure of teeth. Immediately from the head there are huge pectoral fins, it seems that they are fused with the head. Stingrays swim with the help of these fins, the work of which sets the whole body in motion. This is how stingrays differ from their relatives - sharks, whose main thing in swimming is their powerful tail.


The teeth of stingrays fit tightly together and look like a grater. The eyes are located on top of the head, the eyeballs are tightly rooted to its base, which are completely devoid of blink reflexes. Stingrays vary in size: they can range from a few centimeters to seven meters in length.

Stingray habitats

Stingrays are mainly bottom dwellers and their favorite places to live are depths of the sea . Since they are predators, they happily eat small fish, crayfish, and mollusks, which they find at the bottom of reservoirs. Because they live mainly on the bottom of oceans and seas, the color of the dorsal part of stingrays changes from sandy to black. In this way they adapt to the changeable and treacherous bottom world and the color of their back changes for secrecy. The habitats of stingrays are quite diverse: they can live in the cold waters of Antarctica and in tropical seas. They feel very comfortable at water temperatures up to 30 0 C. Many species of stingrays live right off the coast, at a depth of one meter, but there are also those that descend to an ocean depth of up to three kilometers.

Varieties of stingrays

There are more than four hundred species of stingrays in nature. Their appearance and lifestyle directly depend on their habitat.

Here, for example, are some of them:

– this type is characterized by the fact that the weight of this slope can reach up to 2 tons (!) and a wingspan in motion of up to 7 meters. The manta ray looks very fascinating when it is swimming, it resembles a huge fairy bird. A characteristic feature of this type of stingray is that, like dolphins, they love to jump out of the water, reaching a height of up to 1.5 meters and fall back, splashing water in different directions.

- their wingspan is slightly smaller, reaching up to 2.5 meters, and can stretch up to five meters in length. Stingrays of this variety have a kind of spike at the end of their tail, which they use for self-defense and can hit the enemy so that he flies far to the side.

Electric ramps- this type of stingray has a natural gift, an electrical discharge, which can protect the stingray from impending danger or paralyze the victim - prey. The charge of electricity is located at the junction of the stingray's head and pectoral fins. The discharge force of an ordinary stingray can reach up to 40 volts. This blow will be enough to stun the victim, paralyze him and then eat him.

Peculiarities of stingray reproduction

Female stingray, during mating games gathers around itself a huge number of males who, as if spellbound, synchronously repeat all the movements of the female. The most successful and agile male who wins these games receives the right to copulate with the female, which lasts only one and a half minutes.

Stingrays reproduce in different ways: they are viviparous and egg-laying, so-called capsules, each containing a fertilized egg. There is such a species of stingray as the Sea Devil, the female of this species whole year bears one single baby, who is born weighing more than ten kilograms and up to one meter tall. After his birth, the mother loses all interest in her child and he sets off on his own.

  • Stingray is the most stingray dangerous look for a person. On the tail of this species of stingray there is a huge spike, at the end of which there are poisonous cells. When receiving a portion of this poison, a person can be completely paralyzed, blood pressure can drop to a minimum, skeletal joints and muscles can be paralyzed without recovery.
  • The eyes and mouth of a stingray are located in different places on the head and the stingray never sees what it absorbs while eating.
  • People catch stingrays and use their skin to make belts and wallets, and eat the meat.
  • In places where stingrays live, local residents and tourists try to get an electric shock from the stingray. It is believed that by receiving the desired shock of electricity from the stingray, people will get rid of many diseases such as back pain.
  • Ancient people actively hunted stingrays tail-shaped. They used the spines of these stingrays to make arrows. In addition to the fact that they were very convenient for hunting, they were saturated with poison, which helped them in the fight against external enemies. Information about the characteristics, habitats, habits and consequences of encounters with a stingray is so interesting and informative that a whole book would not be enough to describe everything that interests people about these rather unusual creatures.

Stingrays (lat. Batoidea) are one of two superorders of elasmobranch cartilaginous fish. Contains five orders and fifteen families. Stingrays are characterized by a very “flattened” body and large pectoral fins fused to the head. The mouth, nostrils and five pairs of gills are on the flat and usually light-colored underside. The tail is whip-shaped. Most stingrays live in seawater, but there are a few freshwater species(motoro, etc.) The upper side of stingrays is adapted in color to one or another living space and can vary from light sand to black. On the upper side there are eyes and openings into which water enters for breathing - squirts (the first pair of gill slits). Stingrays inhabit all seas and oceans and live both in the cold waters of the Arctic and Antarctic, as well as in the tropics; their habitat temperature range ranges from 1.5 to 30 °C. These fish are found both in shallow water and at depths of up to 2700 m. Most species of stingrays lead a bottom-dwelling lifestyle and feed on mollusks, crayfish and echinoderms. Pelagic species feed on plankton and small fish. The sizes of stingrays range from a few centimeters to 6-7 m in length. One of the most known species The ray is the manta ray (Manta birostris). Large sizes reach rays from the eagle family, whose fin span can reach 2.5 meters, and length - up to five meters; as well as stingrays from the stingray family, reaching 2.1 meters in width and up to 5.5 meters in length. Relatively large stingray sea ​​cat found in Black and Seas of Azov. A special “weapon” is endowed with a squad of electric stingrays, whose representatives, with the help of a special organ made from transformed muscles, can paralyze prey with electrical discharges from 60 to 230 volts and over 30 amperes. Reproduction Stingrays reproduce by laying enclosed eggs on the bottom or by viviparity. In electric stingrays and stingrays, special villi, or trophotenia, additionally develop in the uterus, supplying the embryo with nutrients. Human interaction Stingray wings are a delicacy in Portuguese cuisine. In Korea, stingrays are eaten in the form of hwe (raw): a dish with them is called “hon'ohwe chumuchim” (Kor. ??? ???), this is a “regional specialization” of the South Korean province of Jeollado. Stingray leather is durable and has an unusual texture; it is used in the leather industry for the manufacture of wallets, belts, bags, briefcases, etc. Handles Japanese swords Katanas were covered with stingray skin. Some species of stingrays pose a danger to people. The electric current generated by electric stingrays is enough to stun a person, and stingrays can inflict painful wounds. All species of sawfish rays are endangered or on the verge of extinction. Stingrays are a superorder of elasmobranch cartilaginous fishes, which includes 5 orders and 15 families. Stingrays are characterized by pectoral fins fused to the head and a rather flat body. Stingrays mainly live in the seas. Several freshwater species are also known to science. The color of the upper part of their body depends on where exactly the stingrays live. The latter can be either black or very light. Stingrays are related to sharks. Moreover, the closest relatives. External similarities, of course, is not observed. In terms of their internal composition, stingrays, like sharks, consist not of bones, but of cartilage. In ancient times, stingrays were similar to sharks not only internal structure, but also external features. However, time has changed them beyond recognition. Stingrays are different from each other. Firstly, in size. Nature knows stingrays measuring only a few centimeters and stingrays whose size reaches 7 meters. Secondly, different stingrays also behave differently. Some stingrays do not mind, for example, jumping above the surface of the water, while most of these fish prefer to spend their time buried in the sand. Electric ramp – scary fish. Much more terrible in its essence than, for example, the sea devil. The fact is that the cells of the electric stingray (it is also called ordinary or marbled) can generate electricity up to 220V (of course, the name of this stingray came from this). And how many divers were exposed electric current these stingrays! It is worth noting the fact that all stingrays are capable of generating electricity, but not to the same extent as the electric stingray. The electric stingray has been known for a long time. Its dimensions can be determined as follows: approximately one and a half meters long and a meter wide. Weighs from twenty-five to thirty kilograms. Upper part The body is covered with whitish and brown veins, and therefore the shades may vary. The female electric ray will give birth to live babies. From eight to fourteen cubs can be born at one time. Previously, it was believed that if the cubs were in any danger, the female would take them into her mouth. The cubs stay there until the danger is eliminated. But at present these data have not been confirmed. Electric rays are lazy creatures. They are very slow by nature. However, marble stingrays have a special power, which lies in the fact that the stingray can make any fish motionless just by touching it. Thanks to this unique ability, the stingray does not need to move quickly - having buried itself in the sand, it simply waits for prey. Fish swimming near motionless electric rays quickly become sleepy and lethargic. In the immediate vicinity of a marble stingray, a fish may even die. Fishermen know about this unique ability of the stingray, the force of which reaches the hands through the net and forces them to release the nets. The venom of a living stingray can penetrate the human body even if he touches it with a stick. A dead stingray is completely safe.

Stingray fish – oldest inhabitant water depths. Stingrays are mysterious creatures. They, together with their closest relatives, are the most ancient residents of the depths of the waters.

These creatures have so many interesting features, which is how they differ from other representatives of the fauna floating in the water. Scientists suggest that in prehistoric times the distant ancestors of stingrays differed little in structure, but the myriad of years that have passed have made these animals in no way similar, and the individuals of both species themselves have undergone significant changes.

Modern stingray fish(on photo this is clearly noticeable in the animal) is characterized by an extremely flat body and a head, intricately fused with the pectoral fins, which gives this creature a fantastic appearance.

The color of an animal largely depends on its habitat: sea ​​waters and fresh water bodies. In these creatures, the color of the upper body area can be light, for example, sandy, multi-colored, with a fancy ornament, or dark. It is this coloring that helps the stingray successfully camouflage itself from observers from above, giving it the opportunity to merge with the surrounding space.

The lower parts of these flat creatures are usually lighter than the upper parts. On this side of the animal there are organs such as the mouth and nostrils, as well as five pairs of gills. The tail of such water inhabitants has a whip-shaped shape.

Stingrays are a very large group of aquatic animals that have nothing to do with mammals. Scat– is it a fish or more precisely, a creature belonging to the category of elasmobranch cartilaginous fish.

In size, these inhabitants of the depths also differ significantly from each other. There are individuals only a few centimeters long. Others are meter, and in some cases more (up to 7 meters) in size.

The body of stingrays is so flat and long, resembling a pancake rolled out with a rolling pin, that the edges on the sides of the creatures look like wings, representing pectoral fins. In some cases, their scope reaches two meters or more.

An example of this is the stingray, which is a member of the bracken family, the body length of which reaches up to five, and the span of its peculiar wings is up to two and a half meters. Scat – cartilaginous fish. This means that its insides are not built from bones, like those of sharks and other animals, but from cartilage.

The coloring of the stingray gives it the ability to camouflage itself on the seabed

The habitats of stingrays are as vast as their diversity. Such animals can be found in the depths of water all over the planet, even in the Arctic and Antarctic. But with the same success they inhabit tropical waters.

The depth of the reservoirs that serve as shelter for animals similarly varies greatly. Stingray fish lives and is able to successfully take root in shallow water, but also perfectly adapts to exist at a depth of 2700 m.

Character and lifestyle of stingray fish

Amazing Properties various species of stingrays boggles the mind. For example, on the coasts of Australia you can see “flying stingrays”. There are also electric fish stingrays.

In the photo there are “flying” stingrays

And such strength, given to them by nature, turns out to be an excellent weapon in the fight for survival. Such creatures are capable of paralyzing the victim using their own electricity, which is produced by all stingrays, but this particular species produces it in quantities of up to 220 volts.

Such a discharge, which is especially strong in water, is quite sufficient to paralyze certain parts of the human body, and even lead to fatal outcome. The most interesting of species stingray fish – nautical devil. This is an animal of enormous size, weighing more than two tons.

Sailors created the most incredible legends about such creatures, the reasons for which were the unexpected appearance of such monstrous in size marine stingray fish from the abyss before the eyes of stunned travelers.

They jumped headlong out of the water and then disappeared into the depths, flashing their pointed tail, which often caused panic. However, the fears were groundless, and such creatures are completely harmless and even peaceful in nature.

In the photo there is a stingray "sea devil"

And cases of attacks on people for for a long time was not recorded. Quite the contrary, people often ate their nutritious and tasty meat, which is still a component and integral part many dishes, as well as a wide variety of exotic recipes.

That's just the process of hunting for sea ​​devil can turn into a dangerous activity, because the size of the animal allows it to overturn a boat with fishermen. The main part of the life of stingray fish passes at the bottom of reservoirs. These animals even rest by burying themselves in mud or sand. This is why the respiratory system of these animals is different from other fish.

They do not breathe through gills, but air enters their body through devices called squirters, which are located on its back. These organs are equipped with a special valve that helps protect the stingray’s body from foreign particles that enter from the bottom of the reservoir. All unnecessary trash, particles of sand and dirt are removed from the spray released by the ramp with a stream of water.

Stingrays also move in a curious way, not using their tail at all when swimming. They flap their fins like butterflies, and their peculiar body shape helps the animals practically float in the water, which is why they are excellent swimmers.

Stingray feeding

Stingray fish- a predatory creature. Its main food is fish: salmon, sardines, mullet or capelin. Larger species may be tempted by such prey, as can crabs. Small varieties are content with plankton, as well as small fish.

The diversity of stingrays and their amazing capabilities also manifest themselves in obtaining food. To hunt for your victims various types These fantastic creatures use the weapons that nature has provided them with.

An electric stingray, having overtaken its prey, hugs it with its fins and stuns it with an electric discharge, awaiting its death. And the weapon of the spiny-tailed stingray is its tail, studded with spines, which it thrusts into the enemy. When eating mollusks and crustaceans, it uses special protruding plates that replace teeth for this creature, grinding its prey with them.

Reproduction and lifespan of stingray fish

Some species of stingrays are viviparous, while others lay eggs in capsules. There are also varieties that perform their reproductive function in an intermediate manner, being ovoviviparous.

When carrying cubs, the mother’s body nourishes the embryos with peculiar outgrowths that penetrate the oral cavity. A female sea devil is capable of giving birth to only one cub, but its size is very impressive, and its weight is about 10 kg. But a female electric ray, which gives birth to live cubs, is capable of increasing the genus of rays sometimes by 14 individuals.

Newborns are only 2 cm in size, but from the very first minute of their existence they are able to produce electricity. The lifespan of stingrays most often depends on size. Small species live on average from 7 to 10 years. The larger ones live longer, from about 10 to 18 years.

Some species: the electric stingray, as well as a number of others, for example, living off the Cayman Islands, where the most favorable conditions exist for such representatives of the fauna, live a life of about a quarter of a century.

Stingrays belong to the class of chordates - Cartilaginous fish. What is most surprising is that stingrays and sharks, despite significant external differences, way of life and nutrition, are the closest relatives - there are many similarities in the body structure of these two species, and most importantly, the skeleton of stingrays and the skeleton of sharks does not contain bones, so these two species were combined into independent class chordates – Elasmobranchii – Cartilaginous fish.

Stingrays are characterized by a flattened body shape, by which this type of fish is unmistakably identified. As a result of the fusion of the pectoral fins with the head and body in the anterior part, the body of stingrays can take the form of an oval, disk or diamond.

From below, the stingray's head looks like a funny smiley face; there are gill slits here (usually there are five on each side), the smiling mouth is really a mouth, and the eyes of the smiley face are olfactory openings. The eyes themselves are located on top and in many species they protrude upward.

Behind the eyes there are squirters - these are the entrance holes of the respiratory system, equipped with valves. Most stingrays lead a bottom-dwelling lifestyle, and so that when breathing, sand and other foreign objects are not drawn into respiratory system, the inlets are equipped with valves. When you inhale, the valve opens the hole and water fills the gill cavity; when you exhale, the valve closes and water exits through the gill slits. If a foreign object still gets caught in the spray bottle, the stingray throws it back with a stream of water.


Benthic rays feed on crabs, shrimp, crayfish, mollusks, worms and fish, while they lead a pelagic lifestyle - plankton and fish. Unlike sharks, stingrays do not have sharp cutting blade teeth; their spine-shaped teeth in cross-section are a highly elongated oval. The location of the eyes on the upper side of the disk does not allow stingrays to see their prey close up, but they have no vision of great importance In their diet, stingrays have electroreceptors located on the body and are especially numerous on the lower surface of the head. With the help of these receptors, they perceive very weak electric fields that arise when their prey moves, which predators use when hunting. Electric stingrays are capable of emitting powerful discharges currents that paralyze prey and scare away enemies.

Stingrays live in all seas and oceans in a very wide range of temperatures - from 2 o C to 30 o C; they are found both in the cold waters of the Arctic and Antarctic, and in tropical waters near the coast at a depth of less than a meter. Deep-sea species are also known, living at a depth of 2500-2700 m.

Stingrays are of commercial importance. It cannot be said that they are caught in industrial scale, but in many regions stingrays are very popular with fishermen. For example, meat is used in oriental cuisine, fins prepared according to special recipes are considered a delicacy in Portugal, cartilage is used in both folk and traditional medicine, wallets, belts, and bags are made from durable leather. Dried diamond stingrays are used to make grotesque souvenirs called “Jenny Haniver”. (source site Fish fish in Eilat)

Modern biology classifies stingrays as belonging to the superorder Batoidea; they are systematized as follows:

  • Kingdom -> Animals
  • Phylum -> Chordata
  • Subphylum -> Vertebrates
  • Superclass -> Pisces
  • Class -> Cartilaginous fish
  • Subclass -> Elasmobranchs
  • Superorder -> Stingrays
  • Latin name – Batoidea
Order Stingrays or diamond-bodied rays (Rajiformes)
  • Family Eagle rays or eagle rays (Myliobatidae)

Eagle rays or eagle rays are a family of large rays that, unlike their relatives, lead a pelagic lifestyle. These are huge creatures that freely swim in the open seas of tropical and subtropical regions. The pectoral fins of eagle rays taper or are interrupted at eye level, while the head stands out clearly. Below the tip of the snout, the anterior edges of the pectoral fins of members of the subfamilies Rhinopterinae and Myliobatinae meet to form a protrusion resembling a duck's beak. In members of the subfamily Mobulinae, the anterior edges of the pectoral fins are separate and form horn-like projections near the eyes. It is believed that stingrays use these fins to direct water into their mouths. The head, body and wing-like pectoral fins pointed at the ends of eagle rays form a diamond-shaped body. The whip-shaped tail is very long and in some species is equipped with a poisonous spine at the base. Eagle rays move using the wavy movements of their wing-fins. Manta rays and mobulas filter plankton from the water. Like most rays, eagle rays are characterized by viviparity, and the cubs are born tail first.

  • Family Stingrays or stingrays (Dasyatidae)

Stingrays have a wide disk, a tail that is powerful at the base and thins at the end. The skin is smooth with a small number of small spines. Stingrays got their name because of the jagged, sharp, dagger-shaped spines in the middle part of the tail. In large stingrays, the length of such a spine can reach 37 cm. The tip of the spine is directed backwards, and a channel passes below, into which a poisonous secretion is released. The tail strike is similar to the attack of a scorpion - the tail bends forward and the stingray delivers a powerful blow with a whip-like movement. The poison, penetrating the wound, causes sharp pain and falling blood pressure, tachycardia, vomiting, paralysis. Fatal cases are known.

  • Family Guitar rays (Rhinobatidae)

These stingrays appearance resemble sharks, but the fact that these are stingrays is confirmed by gill openings on the lower surface of the body. They have a small flattened disc and a pronounced rear part of the body with a well-developed tail. Unlike other stingrays, they use the tail as propulsion for swimming, rather than the pectoral fins, which also reminds them of sharks. In most species, the skin contains large placoid scales, which look like a rounded button embedded in the skin with a powerful, slightly curved back tooth protruding above the skin.

They stay at the bottom, inhabit cold and temperate waters, and in the tropics they are found only on great depths. They reach sizes from 30 cm to 2 m in length.

During the day they usually lie on the ground or burrow slightly into it; at night they swim near the bottom. The main method of swimming is the wave-like movements of the pectoral fins. They feed on small fish, bottom crustaceans, mollusks, and echinoderms. The fish are attacked from above, pressed with their body to the ground and then eaten.

Females lay only 1-2 eggs at a time, and during the extended period of oviposition - several dozen eggs in horny capsules with antennae. Development lasts 4-6 months. In meter-long stingrays, the egg length reaches 6-10 cm, and the young stingray emerging from the egg has a length of 10-15 cm.

Order Gnus-like or electric rays (Torpediniformes)
  • Family Torpedinidae

The order Electric Rays includes four families, including approximately 40 species, living in the coastal areas of the tropical and subtropical seas of the Atlantic, Pacific and Indian Oceans. Sizes vary from small - 12-15 cm long, to large - up to 2 m long and weighing up to 100 kg. The body is rounded, the short caudal peduncle is wide at the base, ends in a small caudal lobe and bears one or two small dorsal fins. Placoid scale and there are no thorns.

Unlike other stingrays, electric stingrays are often brightly colored. On the sides of the head there are paired electrical organs formed by modified muscle tissue. Animal electricity is condensed in the electrical organs. The discharge is carried out arbitrarily under the influence of brain impulses. A single discharge lasts 0.003-0.05 s, but usually the stingray produces a series of 20-30 discharges in quick succession. The discharge voltage can reach from 60 to 300 volts with a current of up to 5 amperes.

Electric stingrays are inactive, swim poorly, and usually lie on the bottom, half-buried in sand or silt. When the prey swims up to the stingray, a short series of strong discharges follows, stunning the victim. Large stingrays prey on fish weighing up to 2-3 kg. They also feed on bottom invertebrates.

Stingrays use electrical discharges and in defense, they deliver strong electric shocks if a person accidentally steps on the stingray or tries to grab it. In addition to strong discharges produced during attack and defense, stingrays create around themselves electric field, generating weak discharges with a voltage of 0.2-2, rarely up to 10 and even 50 V and a current of about 1 A, such discharges occur with a frequency of 35 to 300 times per second. The intrusion of any object distorts the uniformity of the electric field. The perception by sensitive receptors of disturbances in the electric field (probably, such receptors are the ampullae of Lorenzini scattered in the skin) makes it possible to judge the approach of prey or an enemy. Apparently, the predominance of this method of reception led to the emergence of several species of blind stingrays.

Ovoviviparous, gestation of embryos lasts up to a year. 4-10 cubs are born at the same time.

  • Family Narcinidae

Narcinoid rays are slow-moving bottom fish, differing from gnus rays in that their electrical organs produce low-voltage voltage - no more than 37 volts. These stingrays are found in all temperate and tropical seas of the World Ocean. They live on the continental shelf and continental slope, maximum depths habitats up to 1000 meters, prefer closed sandy bays, estuaries near coral reefs, river mouths.

  • Family Sawfish or Sawfish (Pristidae)

The sawfish family includes 7 species of sawfish. They differ from other stingrays in their highly elongated flat snout, which is lined with large bony outgrowths on the sides, giving it a resemblance to a double-sided saw. In general appearance, sawfish rays are more reminiscent of sharks than rays.

They reach a length of 7-8 m and a weight of 2,400 kg. The body is slightly flattened, the pectoral fins are relatively small. The gill slits are located on the lower surface of the head.

They live in the shallow waters of tropical and subtropical seas, sometimes entering the lower reaches of rivers (the Australian sawfish constantly lives in rivers). They feed on small schooling fish and various bottom invertebrates. Having burst into a school of sardines or mullet, they beat the fish with a saw like a saber, and then pick up prey from the bottom. In all likelihood, it also uses a “saw” to tear up the soil. They pose no danger to humans unless you grab them by the snout.

It reproduces by laying eggs, which hatch into 15-20 young. In embryos, the snout is soft, and the saw teeth are completely hidden under the skin until birth.

01-08-2015