Family Stingrays or Stingrays (Dasyatidae). stingrays

For the most part, the inhabitants of the Black Sea are harmless and do not pose a threat to people, which makes it one of the safest in the world. But some of them can seriously harm health, even death. Like a Black Sea stingray (or catfish), which has a large poisonous spike and immediately sets it in motion in case of danger. graceful and dangerous fish- frequent guest coastal waters and his meetings with a person are regular, so it’s worth getting to know him better.

Spreading

Black Sea stingray(official name Dasyatis pastinaca ) - one of 88 members of the family, loves warm subtropical waters and is widely represented in the Eastern Atlantic, from the coast Baltic Sea to the West Coast of Africa. This is the only species that lives in the Azov and the Black Seas, preferring the latter.

Being a bottom fish, it prefers the sandy and muddy bottom, where it partially burrows for camouflage purposes. It is mainly found at shallow depths, up to 60 meters, but can migrate deeper, depending on the season and water temperature. It swims in shallow water and to rocky shores, sometimes swims into the mouths of rivers.

Description

The Black Sea stingray has a wide and flattened body that does not have bones (only cartilage, the animal belongs to cartilaginous fish), round-rhomboid in shape, with a snout protruding slightly forward. On the upper (dorsal) part are the eyes, behind which are white splashes, through which water enters the gills. They are bigger size and when opening / closing, it seems that the fish “blinks”. In the lower part there are gill slits and a mouth with two rows of blunt small teeth in the form of plates, from 30 to 40 pieces in each.

The body of the stingray ends with a tail (in adults, it is almost equal to length body, in young animals - 1.5 times more), in the central part of which grows a jagged peak-thorn, reaching 15-20 centimeters in length. With the help of the duct, poison is injected into the body of the victim during the blow. It is because of this characteristic feature fish and received the prefix-name "stingray". From time to time the spikes break, so there may be 2 or 3 of them.

The thorn prick is very painful, and the symptoms resemble poisoning. snake venom: malaise, cardiac arrhythmia, edema, vomiting. Although not considered fatal, they can be fatal if applied to the area of ​​vital organs. Such cases are well known. It takes a few days to recover, but injection wounds take a long time to heal.

Important! As usual, the Black Sea stingray does not attack a person, avoiding crowds or noise, being shy. But if you step on it or “drive it into a corner”, trying to pull it ashore, it hits with its tail immediately, and the force of impact and the sharpness of the spike allows it to pierce clothes and light shoes.

The lower part of the stingray is light, dirty white, the upper part is dark, gray-brown and dirty green-olive colors. The body is smooth and not covered with scales. On average, its dimensions reach 60-70 centimeters in length (the width is slightly greater than the length) and 8-10 kilograms in weight, and together with the tail from a meter, but in warmer and southern seas there are 20-kg specimens 2-2.5 meters. Females are usually larger than males.

Food

According to the nature of nutrition, the Black Sea stingray is a predator. Its diet consists of benthic invertebrates, shrimp, mollusks and small fish. The latter occupies a small part, increasing as the slope grows. It is worth noting that the stingray spike is not used for hunting. It is intended solely for self-defense.

A stingray hunts from an ambush, which suits at the bottom of the sea. To do this, he descends to the soil, clinging to it as tightly as possible and sprinkling himself with a small amount of sand, disguising himself. If “for lunch” mussels or other mollusks with shells, then teeth are used, which easily crumble the defense.

The favorite time for stingray hunting is twilight or at night when it is most active. Second name - catfish- he got just because of this feature. It helps him to see well at night a special enzyme - guanine, which forms a mirror layer in the eyes, upon contact with which even the darkest and dullest picture improves. Together with the ambush attack, this makes his habits very similar to the behavior of pets.

reproduction

By the nature of reproduction, the sea cat is an ovoviviparous fish, and the fry comes out of the womb already fully adapted to life. But even here the stingray stands out. The fact is that the embryo in the egg feeds not only on the yolk, but also on the histotroph ( nutrient similar in function and purpose to breast milk).

Small rays (about 8 cm "on the body" and 20 cm in length) appear in June-July, and the total period of pregnancy and gestation is up to 120 days. After birth, the stingrays spread out over the water area, not showing any signs of “kinship” relationships in the future.

The maximum life expectancy of stingrays is 10 years, and in captivity they can live up to 20. They lead an isolated lifestyle, rarely gathering in large groups.

Meaning

The common stingray is not commercial fish, since the meat does not have a special palatability. Fish liver is valued, containing a large number of vitamin D and is used to make fish oil. In ancient times, poisonous spikes were used as the tips of weapons, and arrows were smeared with poison.

The Black Sea stingray is also used for decorative purposes, as aquarium fish, but this requires large containers and special conditions of detention.

On Grand Cayman, the largest of the Cayman Islands, there is a place named Stingray City, not named after the singer Joanna Stingray, but because of a local attraction. Like all settlements on the island, Stingray City stands on the seashore, and very close to it, on sandy and coral shallows, many stingrays live. The vast majority of them are stingrays, in English stingray - “stinging rays”.

Animal care

Stingrays Dasyatidae
Type of chordates
Class cartilaginous fish
Superorder stingrays
Detachment caudate-shaped
Family stingrays

The stingray family includes 6 genera and about 60 species. They inhabit tropical and subtropical waters of the World Ocean, in some places, mainly in areas of warm currents, they penetrate into temperate ones. They live in shallow waters (from the littoral to 100 meters), almost all the time they stay near the bottom, except for one species - Dasyatis violacea, living in the water column, away from the coast. They are solitary in nature, except during the breeding season or mass migrations characteristic of some species, but are not territorial or aggressive. They feed on crustaceans, molluscs, annelids and other benthic invertebrates, and to a lesser extent fish. body oh round shape, pectoral fins fused in front of the head. The color of the belly is light (white, off-white, yellowish), the back is black, brown or dark gray, in many species with numerous colored spots, stripes or rings. The tail is thin, pointed, whip-shaped, without fins and leathery outgrowths, in most species it is long. In the middle part of the tail is one or more poisonous spikes. Ovoviviparous. Pregnancy lasts about a year. In one litter there can be from 2 to 25 cubs. Immediately after birth, they lead an independent life, reaching puberty in the 3rd-4th year. The maximum known lifespan is 25 years.

The American stingray - Dasyatis americana - is very similar to the sea cat common in European waters (including the Black Sea) - Dasyatis pastinaca, but larger. However, the stingray family does not differ in a variety of forms at all. Together with sharks and a few more exotic groups, rays form a special class of vertebrates called cartilaginous fishes. The word "fish" here is misleading: these animals differ from real fish, perhaps more than humans. And the name "cartilaginous" indicates their main feature: there are no bones in the body of such animals - their skeleton consists of cartilage. Rays and sharks are also related to many other features characteristic of cartilaginous fish: a mouth located on the underside of the body, two rows of gill slits, and a special type of nitrogen metabolism.

However, all these features are noticeable, rather, to the zoologist. And to a non-professional, a shark and a stingray, of course, will seem completely different. The shark's body - triangular in cross section, hydrodynamically perfect - evokes associations either with an airplane or with a hydrofoil boat. The stingray is like a frying pan: its flat body, from which a “handle” extends from behind - a thin and usually long tail, almost of the correct round shape. Although it actually saves triangular section, only this triangle has a strongly stretched lower side. The dorsal fin is practically absent, and the pectorals are very wide and fused at the edges with the head and back of the body, which gives the fish the shape of a frying pan. Even to the touch, stingrays differ sharply from their relatives. If the skin of a shark is completely covered with hard and sharp placoid scales (which differ little in structure from shark teeth), then the soft and delicate skin of stingrays does not have scales at all.

Such a dissimilar appearance reflects differences in lifestyle. Sharks live in the water column and are in constant motion all their lives. The vast majority of stingrays, including all stingrays, live near the very bottom and usually at shallow depths, that is, in the coastal zone. Barely moving the edges of its body, like the hems of a cloak, the stingray slowly swims above the very bottom in search of prey - various kinds of benthic invertebrates.

This leisurely hunt is carried out literally blindly, since his eyes are located on the upper side of the body, he cannot look down. But on the lower side there are nostrils that have nothing to do with breathing and work only as an organ of smell, as well as electroreceptors that capture disturbances. electric field caused by living beings. Of course, no matter how sensitive these organs are, they can only catch slow-moving animals. Common prey for stingrays are crustaceans, mollusks, and echinoderms. Many of them are protected by a strong shell or shell, but this does not bother the hunter: his plate-like teeth are able to gnaw through almost any armor.

When the stingray is not busy looking for food, it simply lies at the bottom for a long time, sometimes also burrowing into the sand. Such a pastime is not compatible with the shark's way of breathing, in which water is forced into the gills through the mouth. The mouth of the stingray is pressed to the ground - it has a different pattern of water movement: it enters the pharynx through special holes - sprinklers located on the upper side of the body. This allows the animal to breathe without the risk of clogging the gills with sand. Of course, the power of the water flow with such a scheme is small, but the stingray does not need a lot of oxygen: its lifestyle does not imply long and intense muscle tension.

A slow-moving creature with delicate skin and a boneless body is too much of a temptation to marine predators, which is enough even in shallow water. Disguise alone is clearly not enough to survive here, so different groups stingrays have chosen various means of self-defense. Most of all, the imagination of people is struck by electric skates, in the body of which part of the muscles has turned into real electric batteries capable of delivering a discharge with a voltage of over 200 volts. The weapon of stingrays is a long, thin and flexible sword-tail, equipped with a sharp spike (in most species, one, in some, two or even four). This spike, which is a modified placoid scale, is the only evidence that the ancestors of the stingray once had scales. It is very hard and strong, its surface is covered with notches directed backwards, and on the underside there are two grooves connected to the poisonous gland. However, stingrays use their poisoned dagger only for self-defense. An attacked or disturbed stingray delivers a swift and accurate blow with its tail in the direction of the perceived threat. The tail wraps around the attacker, like a whip belt, while the spike instantly leaves the "sheath" - the folds of skin that cover it in a calm state - and pierces the enemy's body.

Pliny the Elder wrote that the spike of a stingray pierces even wood and armor. This, of course, is an exaggeration, but the impact force of the tail of a large stingray is sufficient for the spike to pierce the fabric of a wetsuit or leather shoes. A thorn prick is extremely painful, causing a drop in blood pressure, weakness, and a violation of cardiac activity. If the blow fell on the arm or leg (as most often happens), the limb is paralyzed for several days. Death is extremely rare, but possible. This is how the "crocodile hunter" - the famous Australian TV presenter Steve Irwin - died. September 4, 2006 during the filming of the film "The Most dangerous inhabitants ocean" he was stung by a stingray. The thorn struck in the chest, and Irwin's heart stopped before he could be helped.

This, of course, is an exceptional case, but in general, collisions of stingrays with people are not uncommon. Only on the coast North America stingrays injure about 750 people a year, but the total annual number of victims in the world is probably measured in the thousands. Most of these incidents occur due to a misunderstanding: a bather, wandering along the bottom, steps on a stingray that is lying, merging with the ground. But fishermen also contribute to the number of those stung: in some countries, stingrays are considered a valuable commercial fish. For example, in Korea, stingray meat is valued more than other rays. Not only people get hit with poisoned stylets: zoologists have found stingray spines in the lungs, chest cavity, liver and pancreas of Atlantic bottlenose dolphins. At the same time, the remains of stingrays were not found in dolphin stomachs, and no one has ever seen dolphins prey on stingrays. Apparently, a curious dolphin accidentally stumbled upon a camouflaged stingray and received a painful prick.

In principle, stingrays are so curious and non-aggressive that they can be tamed right in the sea. Hundreds of people come to the shallows of Stingray City specifically to interact with the rays. They take pieces of fish from their hands, let them stroke their silky-soft bellies, or arrange something like a spa for themselves, floating above the scuba diver and bathing in the bubbles of the air exhaled by him. Despite the abundance of stingrays and their close contact with people, there are no injuries here. True, here the fish keep at a depth of several meters, so it is difficult for even the most careless tourist to step on them.

A special chapter in the life of stingrays is reproduction. They (like all cartilaginous fish in general) have internal fertilization. He is preceded by a rather long courtship: the male first follows the female, then grabs the edge of her body near the head with his mouth, and she literally captivates him. At the climax, he tucks his belly under the belly of the female and clings tightly to her. At the same time, the partners do not see each other, because, as we remember, the eyes of the rays are located on the dorsal side.

Many stingrays lay eggs - it is somehow strange to call these large quadrangular leathery capsules with re-bag ribbons at the corners “caviar”. Many, but not stingrays. In this group of rays, the embryos develop inside the body of the female, inside a special organ similar to the uterus of mammals. Each embryo is initially located in the egg, but leaves it with growth. At this moment, the nutrition of the little stingray ends due to the yolk sac, and it is still too early for him to go out into the world. At this stage, the walls of the uterus form special outgrowths - trophonemes, penetrating into the spatters of the embryo and through them into the digestive tract. There they secrete a special nutritional secret (analogous to milk), on which the future stingray grows until birth. We can say that this cub feeds on mother's milk right in the womb.

Pregnancy in stingrays lasts about a year (11-15 months depending on the species) and ends with the birth of only a few large cubs. Immediately after birth, the stingray spreads its folded, like a newborn butterfly, “wings” and sinks to the bottom. He already knows everything necessary for an independent life: what creatures are edible, how to react to the approach of the enemy, etc. From now on, he will always rely only on himself.

blue-spotted stingray belongs to the family of cartilaginous fishes (lat. Dasyatidae) of the order of tail-shaped superorder of rays.

This beautiful stingray with large bright blue spots on an oval body and with blue stripes on the sides along the tail is found everywhere in the Red Sea. Its snout is rounded, slightly extended forward, forming a smooth sharp angle. The disc is very wide, the tail at the base is thick, powerful, and tapering towards the end, thin and pointed, about twice as long as the body. The back is predominantly olive green in color with gray-brown hues, the lower part is white. The skin is smooth, without scales and numerous small spines.

On the upper surface of the tail, closer to its end, there is a sharp, flattened, like a dagger, spike, the length of which can reach 37 cm. The spike is covered with coarse notches along the edges. The spike is attached directly to the skin with its base and lies on the surface of the tail back with a tip. A groove runs along the lower surface of the spike, in which cells are located that secrete a poisonous secret.

The spike of the stingray represents formidable weapon and used for defense. Large reef sharks, which are the main enemies of stingrays, often wear fragments of spikes on their heads, indicating past skirmishes. By itself, the spike is motionless, but acting like a whip with its tail, the stingray can deliver very powerful blows. The force of the impact is such that the spike easily pierces leather shoes or several layers of clothing and enters deep into the body of a person who accidentally disturbed a stingray lying somewhere near the beach. The poison penetrating into a stab wound is very toxic and causes sharp spasmodic pain. At the same time, blood pressure drops, a strong heartbeat occurs, vomiting begins, and muscle paralysis is sometimes observed. There are cases when injections of stingrays led to death.

The Indians of Central America make spearheads and daggers from the spikes of stingrays, and drums are covered with leather. The spike of the stingray inspires fear in fishermen, if a stingray gets into their nets, they cut off its tail and only then the crippled animal is released back into the sea. On the Web, you can find a small number of photos of the Blue-spotted stingray with a severed tail. For example this one:

Lives in the Indo-Pacific region: in the Red Sea, from the coast East Africa to the Solomon Islands, from the southern tip of the Japanese Islands to the northern coast of Australia. Leads a benthic lifestyle, almost never rising into the water column, prefers shallow water, but is also found at a depth of up to 20 meters.

Occurs on coral reefs, migrates to sandy shallow waters during high tides in search of mollusks, worms, shrimps and crabs. At low tide, it hides in grottoes or under coral ledges, rarely buries itself in the sand.

Small specimens of stingrays are popular with marine aquarists - several photographs of this stingray were taken at the El Gouna Aquarium.

The maximum disk diameter does not exceed 70 cm. There are reports of giant Blue-spotted stingrays up to 240 cm, but they are probably wrong (FishBase.org).

The blue-spotted stingray is an ovoviviparous species. The cubs developing in the womb, in addition to nutrition due to the yolk of the egg, also receive royal jelly, rich in proteins, which is secreted by special outgrowths located on the walls of the uterus. Bundles of such outgrowths penetrate the spatters of the embryos, and the nutrient fluid enters directly into the digestive tract.

Stingray liver contains approximately 60% fat, rich in vitamin D. In some regions, it is used in medicine and to obtain fish oil. The meat is edible, they are caught on a hook or hit with a harpoon, but wide commercial value he does not have. In Singapore and Malaysia, stingrays are grilled over charcoal and then served with spicy sambal sauce.

Sources:

• FishBase.org
• Randall, J.E., G.R. Allen and R.C. Steene, 1990. Fishes of the Great Barrier Reef and Coral Sea. University of Hawaii Press, Honolulu, Hawaii. 506 p.
• Wikipedia

In Anapa you can meet a real sea cat. It's not simple striped cat who loves sea ​​water, but a species of stingray that lives in the Black Sea. There are several opinions why this marine inhabitant received such a name. Perhaps because of the tail, which resembles a cat in length, or for the grace in movement that nature has endowed the stingray. But the fact remains that cats are found even under water.

External signs

The sea cat has a flat shape in the form of a disk, thanks to the lateral fins fused with the head. The flat body is rhombic, slightly larger in width than in length. The body of the stingray is bare without scales, without thorns and outgrowths. It has a long tail, with upper and lower fins. On the tail is a poisonous spike for protection, the length of which reaches 35 centimeters. The color of the upper surface of the body is uniform and may vary depending on the habitat, the lower part has a white tint. Stingray stingray in Anapa is usually up to 1.5 meters, in other seas there are individuals up to three meters, females are larger than males.

Stingray habits

Stingrays are bottom dwellers, they love sandbanks, where they camouflage and hunt. They prefer shrimp, small fish and a variety of shellfish. The female stingray gives birth twice a year. Scientists still do not know the intricacies of breeding fur cats. It is known that stingrays are viviparous animals, the mother gives birth at a time from 4 to 9 cubs.

There are legends about the "terrible" stingray spike. Today I heard another story about a huge stingray that almost killed a bather in Anapa. But it is known for sure that in ancient times, stingrays were respected and feared along the entire coast. The venom of their thorn was said to be incurable and deadly. In the myths of the ancient peoples, it was said that demigods could be killed with arrowheads smeared with stingray poison. Despite the legends, you should be careful with live stingrays. Their injection can cause serious consequences and severe pain. Every year, about a hundred citizens who have stepped on a stingray turn to Anapa hospitals. There were no fatal cases when meeting with a stingray.

Sea cats are heat-loving fish, in winter they go to the seabed, where the water does not have time to cool.
The lifespan of a stingray is about 10 years. AT marine aquariums an animal can live twice as long.

Where to see in Anapa

Throughout the sandy shallows in Anapa, stingrays have been recorded. In most cases, the stingray fears a large crowd of people. If you want to see the life of a stingray in wild nature, you need to go to wild beaches. But always remember to be careful with dangerous view stingray.
The stingray is rarely eaten, it has no commercial value.

Rays are called waterfowl. Where does this nickname come from? amazing fish, it becomes clear to anyone who has seen how stingrays move in the water. The tail is not used for swimming. Stingrays swim, making movements that are more similar not to the vigorous strokes of the fins of other fish species, but to the flapping of butterfly wings.

The peculiar structure of the body of stingrays significantly distinguishes them even from their closest relatives - sharks. However, it should be noted here that the ancient stingrays were outwardly very similar to their "relatives" - external changes began later, and they mainly affected the external appearance. Internal structure stingray and sharks remained similar. Both those and others belong to cartilaginous fish, which are distinguished by the absence swim bladder and an unossified skeleton. Stingrays have no bones - only cartilage.

The transverse mouth opening, nostrils, and five or six pairs of gill slits are located on the underside of the head. The eyes and specific respiratory squirts are on top - it turns out that the stingrays are not destined to see what they eat.

Stingrays are bottom fish, often burrow into the sand, which influenced the formation of the respiratory system. Through the spiracles located at the top of the head (just behind the eyes), the fish inhales, exhaling through the gills. If, during inhalation, particles of dirt and silt get into the spray, the stingray abruptly throws out a jet of polluted water.

Structural features of slopes

The structure of the stingray has a number of features that significantly distinguish representatives of the superorder Batoidea from other fish species.

Flat body diamond-shaped or rounded

Front fins fused to the head

Swim bladder missing

Gills are located on the underside of the body

cartilaginous skeleton

Electroreceptors that allow you to pick up impulses from other fish (for example, heartbeat)