Katran: Black Sea spiny shark, what kind of fish is it, is it dangerous for humans, photo and description, dimensions

The most common shark in the Black Sea is the Black Sea katran. What is she like? Is it dangerous for humans? This question is often asked by guests of Crimea, admiring the azure expanses of the sea from the numerous beaches of the peninsula. No, you don’t need to worry about scary, toothy fish swimming directly towards swimmers splashing in the surf. The Katran shark is small in size. She herself is afraid of people, cannot stand warm water and never goes near noisy beaches. A tourist who comes to the peninsula will most likely see it in numerous photographs, in beautiful aquariums and oceanariums, for sale on market stalls or already prepared on plates in a restaurant.

Interesting! People often joke about the katran shark that it is the “sister” of the sturgeon. There is a deal of truth in it. If you look closely at both fish, you can see great similarities. Both the Katran and the sturgeon really belong to the same type - chordates.

What does a Katran shark look like?

This is a relatively small cartilaginous fish with an elongated and streamlined muscular body. This is not the smallest shark in the world. Males are smaller than females and grow up to 1 meter. The length of females reaches 1.5 m. The weight of the largest fish can reach up to 15 kg. Males and females are colored the same, brownish-gray or bluish-gray. The ridge and back are dark, the belly is grayish-white or white. There are a few small white small spots on the sides. For this reason, the katran is also called the spotted shark.

Great speed is achieved by strong movements of the long muscular tail and large fins. A light, flexible cartilaginous skeleton and a liver full of fat are responsible for the excellent buoyancy of the fish. The Katran's eyes are large and quite sharp. Like most sharks, it has an excellent sense of smell and is able to smell a tasty smell that interests it from several kilometers away. The structure of the teeth is the same as that of other related marine predators. Several rows of identical sharp teeth growing on both jaws are constantly replaced. During the life of a katran, more than 1000 pieces can be exchanged.

Interesting! If you read, look and compare the descriptions of large sharks (blue, white) and the katran, it becomes clear why filmmakers so often film the sea dog as a smaller copy of the terrifying killer sharks. It looks very similar, but is much less dangerous.

The skin of the katran is covered with placoid (plate-like) scales; each scale has a kind of hook-tooth that makes the skin rough, like sandpaper. The composition and structure of these spines are similar to the structure of shark teeth. In the old days, catran skins were even used for processing wood as sandpaper. The two dorsal fins are equipped with relatively large, sharp spines, for which the fish got its name - the spiny shark. The anal fin is absent. Long pectoral and ventral fins without spines.

Interesting! The name “katran” goes back to the ancient Greek “kedroni”, derived from the word “kedron”, which meant a hard, sharp cone or thorn. The name of the coniferous tree cedar comes from the same word.

Origin of the Black Sea katran

Shark-like creatures have been living in the planet's seas for millions of years. The ancestors of all modern sharks appeared 450 million years ago. They gradually changed from huge megalodons, which competed with ichthyosaurs, to modern sharks. By the Permian period (298 million years ago), creatures similar to modern katrans appeared. The spines on the fins of today's spiny sharks serve as reminders of those times. The same thorns are found on their fossilized ancient ancestors.

Where does moray eel live?

Photo: Moray eel fish

Moray eels lead a secretive lifestyle, settling in reefs, rocks, and large sunken objects. They choose narrow crevices in which they make temporary shelters and wait for prey. Moray eels are common in all warm waters, and different species can be found in certain seas. For example, in the Red Sea: snowflake moray, geometric moray, elegant moray, star moray, zebra moray, white-spotted moray. Different types of moray eels can be found in the Indian, Pacific and Atlantic oceans.

Moray eels are thermophilic and settle in bottom zones, but sometimes they can also be found in shallow waters. Moray eels are also bred as aquarium fish, but they are extremely difficult to keep. An aquarium for three small moray eels should be at least 800 liters, and you need to be prepared that moray eels can grow up to one meter in length. The decoration of the aquarium is a must - many high-level shelters in which moray eels can hide. The fauna of such an aquarium is also important. Moray eels depend on an ecosystem that must include starfish and some cleaner fish. It is better to choose natural materials for accommodation, avoiding plastic and metals.

Now you know where this strange fish is found. Let's see if moray eel is dangerous for humans.

Is an encounter with a Black Sea shark dangerous for humans?

The ratio of the sizes of a person and a katran shows that this shark can hardly pose a danger. People are too large for her and cannot become potential prey. The danger may manifest itself in other ways. Like any shark, the Katran has many sharp teeth, so you should not grab the shark by the tail or try to stroke it. She might bite. In addition, the spines on the fins of the katran are poisonous, covered with mucus saturated with harmful microorganisms. This poison is not fatal to humans, but the injections of such thorns can be very painful and do not heal for a long time.

Most often, fishermen suffer from such injections and bites. However, this shark is not dangerous for them either: the bite of a katran is no worse than the bite of a pike perch or pike. The sea dog is not able to bite through a wetsuit, so experienced divers allow themselves a kind of entertainment. They feed the dogfish, hand-feed them, in order to photograph or video capture spectacular footage of a person interacting with a wild shark in the natural environment.

Interesting! The katran sea dog received its nickname because it harms fishermen. The shark feeds on commercial fish. In search of prey, it can chew through fishing nets and eat fish caught in them.

Population and species status

Photo: What a moray eel looks like

Moray eels have never been on the verge of extinction. They have no nutritional value for marine predators and are dangerous aquatic inhabitants. There is no targeted fishing for moray eels, but sometimes individual individuals are caught by people for food. Moray eel meat is considered a delicacy. By analogy with puffer fish, it must be prepared correctly, since some organs of moray eels or a certain subspecies of moray eel itself can be poisonous. Moray eel venom can cause stomach cramps, internal bleeding and nerve damage.

A popular dish is moray eel ceviche. Moray eel is marinated in lime or lemon juice, then chopped into pieces and served raw with other seafood. This dish is very dangerous, since raw moray eel meat can cause unforeseen consequences. Although it is noted that moray eel meat is very tender, reminiscent of eel in taste. Moray eels are kept at home. Their behavior in aquariums can be different, especially if moray eels are introduced there artificially and not bred from breeders. Sometimes they can be seen in the aquariums of shopping centers, but moray eels do not live there for more than ten years due to constant stress.

Moray eels repel some people with their appearance, but fascinate others with their graceful movements and their lethality. Even a small moray eel can be at the top of the food chain without fear of large predators and sharks. Moray eels have many species, varying in color and size, some of which can be easily kept at home.

From fry to adult fish

Biological scientists characterize the reproduction of dogfish sharks with the word ovoviviparity. This means that the eggs are fertilized inside the fish’s body, and the fry develops there. After 18 months, small sharks appear, about 20–27 cm long. Their “birth” occurs in shallow water, because the breeding environment must be safe and comfortable for newborn sharks. Here, young Katran fish feed on the fry of various fish, shrimp, etc. After 12–15 years, the Katran fry grow to the size of an adult shark and become sexually mature. These fish live on average 25 years, less often they live up to 50 years. In the educational and scientific literature there is data about long-lived sharks who have lived up to 75 years. The very poisonous thorn that you should be wary of helps you find out the age of the katran. If you cut it, rings will be visible, similar to the growth rings of a tree. Just like on the tree, each of them corresponds to one year of the shark's life.

Where do Katrans live?

The Black Sea katran, in Latin its name is Squalus acanthias ponticus, lives only in the Black and Azov seas. Through the Kerch Strait, sharks enter the southern part of this shallow sea. But this is not the only representative of dogfish sharks - Squalus acanthias, the most common species of shark on the planet. There are a lot of different subspecies of katrans that are very similar to each other in the world. They live in seas and oceans in temperate latitudes throughout the planet. In addition to the Black Sea subpopulation, there are Mediterranean, Australian, South African, and South American subspecies of dogfish sharks that differ from it. Several different subpopulations live in the Atlantic and Pacific oceans. The names of spiny sharks vary from place to place. This is not only the common katran. They are also called:

dog sharks;
blunt-snouted, prickly ones;
butchers. This name may also sound like marigold;
southern katrans;
short-nosed;
dark-tailed;
Japanese;
sandy.

This fish is also a shortfin spiny shark, etc.

Typically, dogfish sharks prefer to be in the bottom waters in shelf zones, but they can also move in the water column or even rise to its surface. But they do this only in cool weather. They like water at temperatures from +6 to +16 degrees. Seasonal migrations are typical for katrans. The journeys of these small sharks can be surprisingly long. At the same time, they gather in flocks consisting of individuals of the same sex and size. Unlike its oceanic relatives that live in deep waters, the Black Sea katran does not descend to depths below 120 meters. They are prevented from diving below by hydrogen sulfide on the Black Sea floor, which contains no life.

Habitats

The spiny shark is ubiquitous on the continental shelf of the temperate climate zone.

The range is extensive. It can be described as follows:

Western Atlantic - from the island of Greenland to the coast of Argentina;
Eastern Atlantic - from Iceland to South Africa;
Mediterranean Sea;
Black Sea;
Pacific Ocean - in the areas of New Guinea, Japan, Korea, Northern China, the Bering and Okhotsk Seas;
South coast of Australia and New Zealand.

Depending on their habitat, these fish have a number of populations. The Black Sea katran is the only representative of sharks that lives in the European part of the Russian Federation. Those sharks that swim into the Far Eastern seas of Russia belong to a slightly different, albeit related species.

What does Katran eat?

Like most other sharks, the Black Sea shark eats what it can eat. It feeds on those fish that fit into its sickle-shaped mouth. The menu of the Black Sea subspecies includes all local small fish: anchovy, sprat, red mullet, smarida, horse mackerel, silverside, gobies, small Black Sea-Azov herring, etc. Due to its small size, this shark is not able to cope with larger creatures. Its diet is sometimes varied with various mollusks, crabs, shrimp, bottom-dwelling Nereis worms and even algae.

Commercial value

Along the Black Sea coast, katran fish have long been caught by amateurs using a fishing rod from the shore or from a boat. In addition, in all the Black Sea countries, the katran is valued as an excellent commercial fish, and large industrial catches are carried out. Excellent balyk products are made from it; it can be fried, boiled, smoked, canned, etc. Katran meat is tender and very tasty, unlike the meat of other types of sharks, it does not have an ammonia smell. When properly processed, real delicacies are prepared from it. Katrans belong to the class of cartilaginous fish. This means that they have a soft cartilaginous skeleton and there are no hard bones in their meat.

The size of the katran liver and its fat content are surprisingly large. The liver takes up up to 30% of the total weight of the fish. Therefore, this subspecies of spiny sharks is caught to obtain the famous important vitamin product - fish oil. Katran fat serves as a natural source of vitamins A and D, which are necessary for the treatment and prevention of many diseases, for the proper development of the child’s body, to maintain the health of residents of the northern regions, etc. Specific fish glue has long been made from cartilaginous skeletons, heads, and fins. The result of recent scientific research has been the isolation of a new powerful antibiotic from the tissues lining the stomach of katran.

Interesting! Industrial fishing of spiny sharks in the Black Sea has been carried out for a long time and in such quantities that recently, due to a decrease in the natural population in Russia, the katran has been classified as a vulnerable species. That is, to species that may be threatened with extinction. Therefore, recently measures have been taken to protect and revive large natural populations of this fish. In different countries, the conservation status of the katran varies from a species close to vulnerable in Romania to an endangered species in Turkey.

Crimea is rich in a variety of interesting and remarkable objects, they can be not only palaces, mountains, museums, caves or ancient fortresses. The cute Katran shark is worth getting to know better. Some will be able to admire this graceful predator in its natural environment. To do this, you will have to go on an underwater trip with divers. Others prefer visiting an aquarium, where they can see this beautiful fish in detail through the glass. In any case, it’s worth spending a little time getting to know her.

Goblin shark: an unusual guest from the Pacific Ocean

And now a little history. In 2010, in Crimea, off the coast of Sevastopol, local fishermen caught a Goblin shark, which lives in the depths of the Pacific Ocean. Naturally, they were puzzled by such a catch, as a result of which the sensational catch led to investigations into how this creature could get into the waters of the Black Sea, which is located thousands of kilometers away from her home. Here is what is said about this in the expedition reports of the Kharkov researcher of anomalous phenomena Sergei Petrov:

“Sevastopol fishermen were quite surprised when they caught this monster. Many sea reptiles have been seen here, but this is the first time such a specimen has been caught. The footage posted on the Mobile Reporter website shows how the sailors do not know what to do with the catch. A goblin shark, goblin shark, rhinoceros shark or scapanorhynchus (lat. Mitsukurina owstoni) got caught in the fishermen's net. The fish got its name for its bizarre appearance: the shark’s snout ends in a long beak-like outgrowth. This species has been little studied; less than five dozen specimens are known to science.

The brownie lives off the coast of Japan in the waters of the Pacific Ocean, and how it ended up in the Antlantka, where the salinity of the water is different, is unclear. “I know cases when a blue or tiger shark swam, but they swam to the shores of the Bosphorus and went back, for them this barrier of salinity turned out to be insurmountable,” says Alla Korotkova, curator of the Sevastopol Aquarium Foundation. The brownie shark lives at a depth of 200 meters. This species has been studied very little. It is not even known whether it is endangered or aggressive towards humans.

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For Sevastopol oceanologists it is now a mystery how long the goblin shark lived in the Black Sea. But whether this marine inhabitant was the only representative of its genus in the Sevastopol Bay is unknown. These sharks feed on a variety of organisms that live in deep waters. They eat fish, including other sharks, and can reach lengths of 3-4 meters (there may be larger sharks of this species, but the longest goblin shark discovered was 3.8 meters long). They also feed on crustaceans and squid, octopus and cuttlefish.

The goblin has several rows of teeth, some of which are used for catching prey, while others are used for cracking the shells of crustaceans. The front teeth are long and smoothly framed, while the rear teeth are adapted for gnawing. Up to 25% of the goblin shark's body weight is its liver. This contributes to the buoyancy of the shark, which, like all sharks, lacks a swim bladder.

These sharks hunt, sensing the presence of prey thanks to special sensitive organs; their vision is weak due to the lack of light at great depths. Once the shark finds its prey, it suddenly shoots out its jaws, using a tongue-like muscle to grab the prey with its sharp front teeth."