A clean and well-maintained aquarium is not only beauty, but also a guarantee of a long and healthy life its inhabitants. But sometimes, despite the efforts of the owner and even the work of high-tech equipment, the home reservoir is covered from the inside with a brown or dark green coating, tassels, fringe or threads. This is algae. If this problem overtook you, then do not rush to grab immediately for chemicals. Try hosting algae eaters, for whom eating such “garbage” is one of the natural physiological processes. About which orderlies of the aquarium are known and against which algae they are most effective, read in our article.

Most often in aquariums of amateurs there are these "cleanliness workers"

catfish

Particularly good "cleaners" are:

  • pterygoplicht (brocade catfish);
  • ordinary;
  • (pygmy catfish), which prefers diatoms.

With their suction cup, they thoroughly clean everything (bacterial film, algae growth, other polluting organics), starting from the walls of the aquarium, soil, stones and ending with snags and large plant leaves. At the same time, they themselves are quite unpretentious, which is a definite plus.

Of the minuses, it is worth canceling the large sizes and bad character some of the catfish.

  • For example, an adult pterygoplicht can grow up to 40-45 cm and begin to behave aggressively towards other inhabitants.
  • With insufficient food, some owners of "suckers" may begin to feed on the mucus of clumsy large fish that are attacked under cover of night.
  • Sometimes catfish, overly enthusiastic about cleaning, damage young tender tops of plants or make holes in young leaves.
  • And some individuals with age begin to be lazy and perform their "duties" poorly.

The pygmy catfish or algae-eating otocinclus from the chain catfish family does best with brown diatoms. A flock of five fish can easily keep a 100 liter aquarium clean. "Dwarf" is unpretentious, peaceful, able to get along even with large predators.

The “janitor”, which can be seen less often, but this does not make it worse: the royal panak, belonging to the chain catfish family. Large fish, for which you need a 200-liter (at least) aquarium. Young individuals are calm, but with age their character noticeably deteriorates. They get along well with peaceful haracins. Best of all, panak cleans driftwood.

A suction cup with which chain catfish cleans fouling from surfaces.

Girinocheilaceae

This family includes only three types of fish, the most popular of which are.

Their lips are like a sucker with folds on the inside. These bends form a kind of "grater".

Thanks to this design, fish can stay on the rocks even in strong currents, while at the same time scraping algae from their surface.

This food is not very nutritious, so the Girinoheylus have to “scrape” a lot.

All filamentous algae, such as filamentous algae and blackbeard, they cannot eat.

The negative points are

  • damage to the leaves, on which furrows and holes may remain after “harvesting”;
  • a small number of fish is not enough to keep the aquarium clean;
  • in large numbers, they are aggressive and constantly attack their own kind, as they are territorial.

It is very difficult to achieve peace among them. Neighbors also need to be carefully selected, it is absolutely impossible to take slow fish.

Girinocheilus take them for inanimate objects, they can “clean” and severely damage the scales. They also have a bad attitude towards animals that have an elongated body and a dark color - they perceive them as brothers and try to drive them as far as possible.

Gyrinocheilus.

viviparous

Many of them have a strongly developed lower jaw, which resembles a scraper that easily removes plaque from the walls, soil and plants.

The most popular live-bearer cleaners are the guppies, the mollies, and the swordtail. Some breeders claim that these fish can survive even without additional food, eating only green thread.

But they are good only as assistants to other algae eaters, since they are extremely reluctant to eat unwanted fouling.

Live-bearing guppy fish.

Carp

The most tireless fighter against algae from this family is the Siamese algae eater (aka Crossoheil Siamese, or Crossohelius Siamese, or Siamese epalceorhynchus).

His strong point is green algae and the so-called "Vietnamese" or "black beard" (these are growths in the form of dark tassels on stones, plant leaves and other places).

It also copes well with other algae in the form of a fluff, since its mouth is most adapted for this. To keep a 100-liter aquarium perfectly clean, it is enough to have only two (even the smallest) Siamese algae eaters.

The advantages of these fish are also activity, mobility, a rather peaceful disposition, a small volume of the vessel for a normal existence and modest care.

It was not without its shortcomings. After the length of the fish becomes more than 4 centimeters, they can begin to eat Javanese moss, if it grows in an aquarium, and much more willingly than algae.

The way out of this situation is to plant larger mosses such as fissidens.

It has also been observed that as Siamese algae eaters grow, they gradually become accustomed to fish food and over time may lose interest in fouling altogether.

Another couple of "cleaners" from this family are two-color labeo (bicolor) and green (frenatus). Their oral apparatus turned down. Of course, they eat algae and fouling, but not as well as the previous ones. It's more of a hobby, so to speak. Their big minus is the increased aggressiveness and territoriality in relation to both other fish and their own kind.

Siamese watersled in its typical stance. Carefully study the fish and remember its appearance, as pet stores often sell other species under this name.

Shrimp fighting algae

These arthropods are deservedly called champions of cleanliness. Particularly good freshwater shrimp, whose bodies are equipped with special "fans".

These outgrowths filter the water and extract from it uneaten food, particles of plants and what is left of the dead inhabitants. Males loosen the soil and filter the dregs that have risen at the same time. Females clean dirt from the bottom surface.

In addition to filtering water, these creatures remove fleecy algae from plant leaves and all other surfaces, and much more successfully than fish.

The reason is simple - shrimp, especially cherry ones, can get into the smallest nooks and crannies of the aquarium.

Negative points:

  • a small shrimp can only handle a small amount of work;
  • to make the aquarium really clean, you will need a lot of shrimp (one individual per liter);
  • they are very defenseless and can be eaten by fish, as a result of which neighbors must be selected especially carefully, plus a lot of reliable shelters should be created.

In addition to cherries, amano shrimp are good at fighting algae. Perfectly keep balls of kladorfs clean, eat thread.

Important! The efficiency of "work" is affected by their size. The larger the shrimp, the tougher strings of algae it can eat. Four-centimeter arthropods are considered the best.

Enough 5 of these pieces for 200 liters. Three-centimeter will need 1 individual for every 10 liters of water. Small ones need even more (1-2 for each liter). The last option is the most unproductive and the most expensive. It is also worth noting that these shrimp do not eat xenococus and other green algae in the form of plaque. Black beard is also used reluctantly.

Another species is neocaridina. They are most common among hobbyists, as they are very easy to breed. They are small, only 1-2 cm long, so a lot of “combat units” will be required (one individual per liter). Preference is given to soft filamentous algae such as Rhizoclinium. Neocaridines are best choice for planted aquariums. They are also indispensable in a newly launched aquarium, as they help to establish balance. In maturity, they maintain balance.

Amano shrimp.

Snails fighting algae

Although mollusks are not so successful in the role of orderlies, they strong point is the ability to consume almost all pollution (leftover food, excrement of living and dead inhabitants, rotten plants, mucus and plaque on all surfaces, a film from the surface of the water).

And the well-being and behavior of some species serves as a kind of indicator of the purity of the soil and water.

The bad thing is that the number of snails is almost impossible to control, and they multiply very quickly.

Then their large army begins to "harm", eating plants and flooding everything around with their mucus.

But among aquarium mollusks there are not only rapidly breeding pests. Some of the snails cannot breed at all in captivity, others bring a small number of offspring, and still others are interesting and cute, so they will not only be willingly taken away at the nearest pet store, but they may also give something in return.

Here are the cleaner snails most commonly found in home aquariums:

Neretina zebra(tiger snail), Neretina hedgehog, Neretina black ear. They remove plaque from glass, stones, snags, decor and large leaves without damaging them. It seems that they never get tired. Minus - they leave unaesthetic clutches of eggs on the glass of the aquarium, from which juveniles do not hatch.

Neretina zebra.

Neretina horned. This crumb (1-1.5 cm) is able to crawl into the most inaccessible places and clean them to a shine. Works great with diatoms.

Septaria or turtle snail with a flat shell. It is very slow, but despite this, it copes well with algal fouling and Vietnamese. Plants are not damaged. The disadvantage is characteristic - caviar, hung on the scenery.

corbicula. This is a three-centimeter snail. It is also called the yellow Javanese ball or the golden bivalve. Helps to cope with water turbidity, suspension and flowering, as it is a filter. This means that the mollusk passes water through itself (up to 5 liters per hour!), Eating the microorganisms contained in it. Interestingly, in aquariums with carbicles, fish do not get sick, as they somehow trap their cysts. For an aquarium of 100 liters, you need from 1 to 3 of these snails. The negative points include plowing the soil and digging up plants with weak roots.

ampoule. Pretty large lungfish. It picks up the remains of food, dead fish and other snails, actively eats fouling from the walls of the aquarium. One of the disadvantages is that it produces a large amount of waste, so it is imperative to install powerful filtration in a container with this snail.

Theodoxus. These are small beautiful freshwater snails. There are several types. They can live in both freshwater and saltwater home waters. They feed only on fouling, preferring brown and green algae. They even compete with gerinocheilus for superiority in the effectiveness of the fight against xenococus. But they don't like the "beard". Plants don't spoil.

In conclusion, let us say that the aquarium biosystem can successfully exist only with the help of man. Competent selection and adjustment of equipment and lighting, proper start-up of the aquarium, regular monitoring of water parameters and the condition of the inhabitants are very important. Fish, shrimps and snails are helpers in solving the problem of algae control, not the main characters. Of course, here we have only briefly described only some of the representatives aquarium orderlies, since in one article it is impossible to talk about everything in detail. We will be grateful for interesting additions.

Every aquarium needs constant cleaning. But when buying some types of fish, they are able to independently maintain cleanliness in their home. One of these species is tarakatum catfish. Catfish are also called aquarium orderlies. They are able to clean the walls and bottom of the aquarium from algae, waste, food debris, which cause many diseases. The habitat, maintenance and care of tarakatums does not differ from other types of catfish.

Catfish cannot be called beautiful fish with original coloring. But catfish tarakatums are distinguished by a more unusual and attractive appearance.

aquarium fish tarakatum (lat. - Hoplosternum thoracatum) is a species of catfish from the family of armored catfish. Habitat - South America. It lives in abundance in the Amazon River and in rivers near the island of Trinidad. It was brought to the USSR in 1971.

It lives in rivers with a strong current and a small amount of oxygen in the water. Because of this, in the process of evolution, new form respiration - intestinal respiration. They are able to absorb air through the anus.

Appearance

  • Body. The body is long and slightly flattened on the sides, especially in the abdomen. On the sides are bone plates. The head is massive with a sharp muzzle. Near the mouth are two pairs of whiskers. One pair is at the bottom and is designed to feel the river bottom. Other whiskers are straight and slightly to the side. They help to feel currents, water movements and obstacles on the way.
  • Color. Color from light brown to dark brown. On the body, head, fins there are dark spots of small size. The spots appear in adolescence and from then on remain on the body until the end of life. The belly is creamy white or beige.
  • Length. Usually catfish are 10–14 cm in size. But especially large individuals reach a size of 18 cm.

Behavior

The fish is nocturnal, in the daytime it is passive and inactive. It lives in the bottom of rivers and reservoirs, looking for insects and food particles among the sand and stones at the bottom. It does not show any interest in other inhabitants, if they do not invade its bottom territory and do not attack. Because of this quality, the fish is able to get along with almost any kind of fish in the same aquarium.

A post shared by (@mariahxpowers) on Sep 10, 2018 at 3:14pm PDT

Feeding

How large view, tarakatums need in large numbers food and a varied diet.

These fish are able to eat both dry and live food.

  • Dry granular food. It comes in the form of flakes, granules, tablets. It includes the necessary supplements and vitamins. Granular feeds are divided for fry and adult fish, for sick fish, for color improvement, fortified and others.
  • Live food. Catfish use bloodworms, coretra, crushed earthworms, brine shrimp, krill, pieces of meat (for example, shrimp).
  • Forbs. Some catfish like vegetarian food. They are sometimes given dandelion leaves, lettuce.

Tarakatums eat a lot and have a good appetite. Sometimes they take food from other less active fish. Feed the catfish 2-3 times a day, preferably in the dark, and then the catfish will always be full and active.

Compatibility

Catfish get along with almost all species due to their calm and peaceful nature. If the fish do not pester him too much, then the catfish will not pay any attention to other inhabitants. But active and aggressive fish cause stress in the catfish.

Great neighbors will be:

  • Rainbows.
  • Danio.
  • Scalars.
  • Goldfish.
  • Tetras.
  • Rasbory.

Tips for choosing neighbors for catfish:

  • Fish with a body length of more than 6–7 cm. Otherwise, the catfish begins to chase them and will eat them later.
  • Fish should live at medium depth or near the surface.
  • Do not add bottom fish. An abundance of fish that live near the bottom will cause catfish to become stressed and lack territory.
  • Do not keep together with territorial fish such as cichlids, bats.

reproduction

Breeding tarakatums at home is possible and not too difficult. To breed tarakatums, you need several pairs of fish or one male and several females. Before breeding, the water temperature in the aquarium is increased by several degrees.

Before spawning, the male prepares a nesting site. The male builds a nest for several weeks from pieces of the plant and air bubbles. The bubbles do not break because they are covered with a special substance in the mouth of the fish. Large leaves and stems of the plant are used as the frame of the structure.

After building a foam nest, the male begins courting the female. Only a pair will spawn in which the partners are both happy with the choice. If the couple does not work out, then you should not expect offspring. To do this, one male and several females are added, and the male makes his choice.

Sex differences

You can distinguish a male from a female by the following criteria:

  • Fish size. Female tarakatums are much larger than males.
  • The shape, size and color of the fins. An adult male catfish has fins on chest have a more geometric shape and resemble a triangle. In females, the fins are more rounded, smaller in size than in males.
    In males, the first ray of the pectoral fin is thickened and sharp. During sexual activity, it turns yellow-orange.
  • Belly color. During spawning, the abdomen of the male changes its cream color to blue-violet. The abdomen of the female does not change in color, only becomes larger and plumper.

Spawning

Spawning of tarakatums occurs after courting the female. The female lays eggs, and the male immediately fertilizes them and takes them to the nest. Capable of throwing up to 1000 eggs.

After spawning, all care for the offspring falls on the father. He carefully protects the eggs and returns the fallen ones back to the nest. Incubation takes 9-11 days. After that, the male is separated from the fry.

fry care

After hatching, the fry feed on microorganisms in the soil. After 2-3 days they are given crushed earthworm, dry food for fry. Provide shaded areas for fry.

Diseases

Catfish are distinguished by strong immunity, but some diseases are also found in them.

  1. Mycobacteriosis. This disease is manifested in the refusal of food, clouding of the iris, peeling of the scales. A sick individual is treated with Kanamycin. Soil and decorations are disinfected from microbes.
  2. Furunculosis. With furunculosis, the fin turns black, dies, unhealthy spots and abscesses appear on the scales, the abdomen turns red. Treated with Furazolidone.
  3. Gill infection. Symptoms - plaque, red stripes, gray spots appear on the gills; the pet is passive, he has no appetite. The drug Aktimet helps.

The catfish may also lose its whiskers. This happens when the soil is chosen incorrectly. The animal gets hurt on the sharp corners of the stones and the infection gets into the wounds. Because of this, the tissues in the mustache die off, and they fall off.

Amazing and unusual fish- dwellers of the deep. Exists great amount all kinds of creatures that amaze with their sophisticated defense mechanisms, the ability to adapt, and, of course, its appearance. It's a whole universe that hasn't been fully explored yet...

armored pike

Shell pike, or alligator fish, are the largest freshwater fish that live in the waters of Central and North America and the island of Cuba. The body of these fish is covered with a shell of thick and durable scales, consisting of an inner layer of bone and an outer layer of sparkling enamel, or ganoin. Hence their scientific name, ganoids.

These creatures, as if dressed in the armor of medieval knights, are the undisputed masters of all major rivers and their many tributaries that flow into the Gulf of Mexico. As for the correctness of the name "alligator fish", they got it for the shape of the head, which is very similar to alligators.

Moreover, the similarity of the fish in the water is so strong that even local fishermen often confuse these so different representatives of the animal world. Another reason for such a formidable name may be stories about how armored pikes sometimes attack young alligators, biting them in half with their powerful jaws.

Among anglers, there are also stories about the capture of giant armored pikes about 6 m in size and weighing 200 kg. However, according to strictly documentary data, their maximum length does not exceed 291 cm, and body weight - 120 kg.

Even at the beginning of the century, such huge specimens of these fish were caught in the lower reaches of the Mississippi. But prolonged fishing and hunting (large armored pikes are literally hunted with a bow or rifle) have practically exterminated large individuals.

Armored pikes are carnivorous creatures that feed mainly on food of animal origin. A heavy, log-like fish (large specimens reach 80-100 cm in girth) is a poor swimmer and therefore hunts like an ordinary pike, waiting for its prey in ambush.

In addition, armored pikes eat various garbage, thus being aquatic orderlies. It is clear that these big fish should be "good eaters", especially females during the breeding season. The size of the swallowed food can be concluded from the huge opening of the mouth and the structure of the dental apparatus.

There is no other fish in the world that would have such long and powerful jaws (they reach a length of 30-45 cm), seated with huge teeth, like those of a dog. So she swallows her prey whole, or at least in large chunks.

There are cases when large armored pikes ate their own kind, but their usual food is other fish, and their voracity is truly colossal: the stomach of one armored pike contained more than 20 kg various kinds fish.

Often, armored pikes catch and eat ducks and small waterfowl. Any person looking at the powerful, dog-toothed jaws of this fish involuntarily has a question: “Does it attack people?”

Being aquatic orderlies and eating various waste of animal origin, armored pikes often accumulate in places where fish are caught in order to eat the waste generated during butchering.

At this time, they can accidentally grab an arm or a leg, often even dragging the attacked into the depths. It is almost impossible to extract limbs intact from the mouth of a shelled pike. But cases of direct attack by these giant predators on swimming or bathing people, as shown by a survey conducted by a group of scientists in the lower reaches of the Mississippi, are extremely rare even with a direct meeting of a swimmer and a shelled pike.

The reaction, as a rule, is mutual - without delay, both the person and the fish are instantly removed in opposite directions. Single recorded cases of armored pike attacks on swimmers occurred only when the fish were either extremely hungry, or very frightened or injured.

It should be noted that the meat of this huge fish is rough and has a specific taste, and therefore it is little used for food everywhere. Her caviar (about 3 mm in diameter) is poisonous and therefore inedible, although the mass of the ovaries of large females reaches 9-10 kg.

white sturgeon

White sturgeon, one of the largest representatives of the sturgeon family, second in size only to kaluga and beluga, reaches a weight of 500 or more kilograms. species range in North America is vast and stretches along the Pacific coast of the United States - from the Aleutian Islands to California.

One of the largest populations lives in British Columbia. White sturgeon (Acipenser transmontanus) populations are declining due to high concentrations of toxic chemicals (DDT and biphenyls) in the Columbia River Basin (USA). Oregon scientists State University found these and a number of other toxic substances in sturgeon tissues.

This species is important to Oregon's indigenous peoples as a food item. Commercial and sport fishing is allowed. Studies have shown that sturgeon living in some localities located above the Bonneville Dam have a high content of toxic substances in the liver, muscle tissues and gonads.

So far, the source of pollution has not been found, since too many smaller rivers flow into the Columbia River, but the researchers see it as their task to find this source.

Scientists say that determining the size of white sturgeon populations is a rather time-consuming process, but the low percentage of juveniles among the fish caught indicates a decrease in numbers. It is likely that the cause of this phenomenon was water pollution.

frilled shark

Fishermen from the country rising sun caught a very unusual and dangerous fish. She turned out to be a female frilled shark - one of the most ancient and unexplored species. These sharks, little studied by science, live at a depth of 500 to 1000 meters and rarely swim to the surface.

The one that got into the net of Japanese fishermen - pure water accident. This happened because the animal was seriously ill. Biologists put a shark in a pool with sea ​​water to observe the behavior of the occupant sea ​​depths. Unfortunately, the shark lived in captivity for only a few hours.

Fish - Moon (Mola mola).

It reaches over 3 meters in length and weighs 1410 kilograms, and once Atlantic coast USA (New Hampshire) was caught by a supergiant 5.5 m long, whose weight remained unknown.

The short, laterally compressed body of this fish approaches the shape of a disk. (It is no coincidence that the scientific name "Mola" is given to it, which means "millstone" in Latin.)

The larvae and juveniles of this species swim like ordinary fish, while adults spend much of their time lying on their sides, near the surface, lazily flipping their high dorsal and anal fins, exposing them one by one from the water. True, there is an assumption that sick and dying fish do this, which, therefore, are caught without any difficulty and whose stomach is usually empty.

Fish - Moon - a very poor swimmer, unable to overcome a strong current. Sometimes from a ship you can watch how this harmless monster, swaying languidly and putting the top of its dorsal fin out of the water, slowly swims without any visible purpose.

Fish - Moon - the most prolific fish: one female spawns up to 300 million eggs.

Despite the fact that even large moon fish cannot cause any harm to a person, in some places off the coast South Africa fishermen experience superstitious fear when they meet this fish, considering it a harbinger of trouble, and hastily return to the shore.

This, apparently, is explained by the fact that only before bad weather can one see the moon-fish near the coast, and fishermen associate its appearance with an impending storm.

Great dolphin (Coryphena hippurus).

The large dormice reaches a length of 1.8-2 m and a weight of about 30 kg. The color of this fish is extremely bright: the back is painted in sparkling green or Blue colour, sides and belly are cast in silver or gold and have a reddish tint. Blue spots are scattered everywhere on the sides of the body.

The caudal fin is yellow, the dorsal fin is dark blue. Interestingly, the caught dolphin, extracted from its native element, shimmers with all the colors of the rainbow before death, changing color several times from blue to golden.

Dolphins are active predators, eating pelagic fish and squid. Their main food is flying fish, which they fiercely pursue. Sometimes you can see how the dolphin quickly swims after a flying fish flying in the air and grabs it at the very moment when it sinks into the water.

It is interesting to note that relations of the "predator-prey" type are formed between dolphins and flying fish already in early period life. In one experiment, a dolphin fry only 26 mm long, placed in an aquarium with juvenile flying fish about 12 mm long, immediately swallowed one fish and attacked another before being removed.

Dolphin meat has a pleasant taste and is in great demand in many countries. In the Hawaiian Islands, for example, magi magi (this is the Polynesian name for this fish) is considered a delicacy. At the same time, in some other areas (in particular, on the Pacific coast of Mexico), for some reason, dolphins are considered of little value and tasteless.

Dolphins are also very popular as an object of sport fishing.

Toxotes jaculator is a sniper fish.

A characteristic and even unique feature of these small fish, reaching 20 cm in length, is their ability to hunt for air insects, which they knock down from surface plants or directly in the air with the help of water drops sprayed from their mouths.

The archers keep close to the surface of the water and vigilantly observe the movements of moving objects in the surface environment. Seeing an insect crawling along the branches or hovering in the air, they swim up to the very edge of the water, protruding their snout to the surface, and from a distance reaching 1 m or more, knock down the prey, accurately directing drops or streams of water into it.

They aim so accurately (you need to take into account the refraction of light rays at the interface between water and air) that misses happen very infrequently. If the fish missed the first drop, then it corrects the flight path of the next one, directing its "bullets" more precisely.

As a result, a flock of hunting archers, rushing to the discovered prey, leaves almost no chance for it to escape. A downed insect is immediately picked up by one of the hunters on the surface or still in the air, and at this time it often sticks its head far out of the water.

A wonderful way of hunting archers has been known for a long time. In their original habitats, these fish from ancient times were placed in artificial pools for the amusement of spectators, and the targets for their shooting were suspended above the water on threads.

Now archers can be seen in aquariums and zoos around the world. In captivity, these fish willingly demonstrate their exceptional abilities, easily knocking down cockroaches, spiders and ants at a distance of up to 2.5 m, extinguishing a lighted cigar with a stream of water and vividly reacting to any movement above the vessel in which they live.

The famous Russian aquarist N.F. Zolotnitsky, who observed these fish a lot, even noted well-aimed drops in the glasses of his pince-nez when he bent over a vessel with his pets, offering them bloodworms and ants.

And the mechanism of their shooting is as follows. It turned out that on the palate of these fish there is a very narrow, but long groove, which can be covered from below. long tongue, turning into a very thin tube - a kind of trunk, the diameter of which even in large archers does not exceed 0.15 mm.

The thin tip of the tongue is very mobile and serves as a valve that closes and opens the exit from this tube. With a sharp closing of the gill covers, water under pressure rushes from the pharynx into the palatine canal, and the archer regulates the frequency of shots with the tip of the tongue, sending a series of drops or a thin continuous stream of water at the target.

The method of shooting is chosen depending on the position and size of the prey, but also depends on the individual characteristics of each fish. There are suggestions that the largest and most experienced archers achieve the greatest success in their art.

tiger fish

British angler and traveler Jeremy Wade caught this monster while traveling in Africa, during an expedition to the Congo. To say that everyone was shocked is an understatement! The length of the fish is almost one and a half meters - you can see the rest for yourself ...

Tiger fish Goliath - one of the most terrible freshwater fish in the world. Considered to be a larger and deadlier version of the piranha. In length
reaches up to one and a half meters with a weight of 50 kilograms. inhabits
exclusively in Africa, mainly in the Congo Basin.

Armed with a set of 32 large teeth, large individuals even attack crocodiles! Catching such a fish is extremely difficult. sharp teeth it will bite the fishing line of any thickness, so special steel leashes of very high strength are used for this.

It is not so easy to escape from a strong and agile tiger fish: it has a habit of swimming against the current, devouring weaker fish along the way, which cannot cope with the powerful flow of the Congo River. In addition, she reacts with lightning speed to a sudden movement nearby or a splash of water, and is even able to pick up the low-frequency vibrations of her victims. So they don't stand a chance.

Its name is big tiger fish received not only for predatory disposition. On the sides of her body are horizontal dark stripes that make her color look like a brindle. The fins are most often orange or red, and during the breeding season their color becomes especially bright. Interestingly, male big tiger fish are usually much larger than females.

As for the Latin name - Hydrocynus goliath - the fish received it solely due to its gigantic growth. After all, it is known that the Philistine warrior Goliath was the largest and strongest among his fellow tribesmen - his height reached 2 m 89 cm. And although the big tiger fish cannot boast of such dimensions, it still received the name of a warrior.

And here locals her name is Mbenga. They often talk about cases of attacks on careless fishermen: she bit off his finger, injured his hand. It is quite natural that the natives do not really like to mess with her.

smallmouth macropinna

The name of this fish in Latin sounds too boring, because it is easier to call it “fish with a transparent head”. She has a transparent head through which she can see with her tubular eyes.

The tubular eyes and transparent head of the fish have been baffling scientists since 1939, when macropinnae were first caught. The process of studying these fish was further complicated by the fact that after the entry of Macropinna microstoma into the net, the “bubble” burst, protecting the head structures from environmental influences.

Previously, biologists have established that the eyes of fish see very well even in almost complete darkness, that is, they successfully collect light. And these representatives of the Opisthoproctidae family live at a depth of 600-800 meters off the coast of Central California.

However, scientists were surprised by the fact that the eyes of the fish look only in one direction, namely up, to the surface of the ocean, where a potential prey can be detected by silhouette. Given that macropinnas have a very limited field of view, biologists could not understand how fish manage to capture prey with their small mouth.

Bruce Robison and Kim Reisenbichler of the Monterey Bay Aquarium Research Institute (MBARI) have shown that macropinna eyes can still rotate inside a liquid-filled transparent head. Thus, the fish can focus on the prey it is hunting or eating.

In the video, obtained by underwater vehicles, the fish hangs almost motionless in the water column. In the light of the lanterns, her eyes appear bright green. Also, for the first time, scientists saw that the same transparent "shield" is located around the upper part of the head, and the cavity under it is filled with liquid.

Robinson and Reisenbichler were doubly lucky: a little later they were able to catch a few living specimens of Macropinna microstoma. Over the next hours, the behavior of these fish was studied in a special aquarium, and scientists confirmed their guesses - tubular eyes rotate when the macropinna changes its body position from horizontal to vertical.

Biologists have discovered other adaptations to the deep-sea lifestyle: wide flat fins allow you to maneuver very precisely in the water and remain almost motionless in the body of the fish, digestive system makes it possible to digest many types of small drifting animals. In the stomachs of two individuals, fragments of the body of jellyfish were even found.

Scientists believe that most of the time the fish swims in a horizontal position, its eyes are turned to the surface. Green lenses can filter incoming sunlight. When an animal posing as a bioluminescent glow (for example, a jellyfish) swims above it, the fish turns vertically, its eyes begin to look straight, hunting and feeding begin.

stone fish

One of the most poisonous and also the ugliest marine animals is the stone fish.

It is also called tubercles or warts. This creature is only 15-20 centimeters long, with an ugly large head, small eyes and a large mouth with a protruding lower jaw.

Naked, without scales, brownish-brown, sometimes with light spots and stripes, the body of the stone fish is covered with bumps and warts, and hard poisonous spikes protrude from the dorsal fin.

If a person steps on a stone fish or accidentally touches it, it will immediately plunge into it the spikes of its fins, at the base of which there are poisonous glands.

Wart venom is extremely dangerous. There are cases when a person died a few hours and even minutes after being stung by her poisonous spikes.

The stone fish is found in the Red Sea, the Indian Ocean, the Pacific Islands and northern Australia, where the inhabitants call it the warty vampire.

People who are lucky enough to survive a wart injection often remain disabled, because its poison destroys red blood cells and affects the central nervous system.

Lampreys are fish, but very unusual.

The lamprey became famous thanks to its taste preferences - it eats the meat of dead and living fish.

There are about 40 species of these fish. Lampreys live in all temperate waters of the Northern and Southern Hemispheres and even in the Arctic Ocean basin. Often found in Russia, especially in major rivers and lakes.

In European Russia, 3 species are common: stream (lives in streams and small rivers), river (lives in large rivers) and sea (Caspian Sea basin). The river lamprey is larger than the stream lamprey.

Externally, lampreys are more reminiscent of eels than fish in our usual representation. Their body length is 10-100 centimeters. Lamprey skin does not have scales. It has neither pectoral nor ventral paired fins. But on the other hand, it is distinguished by a large annular mouth with many horny teeth and an unusual respiratory system.

Their respiratory system is represented by internal gills, which are spherical sacs. Lamprey cannot breathe like other fish, passing water with oxygen through the mouth and exhaling through the gills. The complexion of the "head" is not the same. Their water enters and exits only through the gills-sacs. Such breathing is dependent on the way of eating.

Lampreys have a brain that is protected from the side of the pharynx by a skull. Central nervous system lamprey is divided into the brain and spinal cord. Unlike other fish. They have no bones or ribs. Their spinal column is replaced by the so-called vyazig.

The sense organs are simple. The eyes are poorly developed. The organ of hearing is the inner ear. The main sense organs are the lateral lines. They are represented by shallow pits, at the bottom of which are the endings of the vagus nerve.

Then a powerful tongue with teeth at the end comes into play. With its help, the lamprey eats deeply into the body of the victim. Then it secretes digestive juices into prey and after a while sucks out already partially digested food.

Lamprey fishing is very common, especially here in Russia. They say she has very tasty meat.

And how much more unknown is next to us on this Planet?