About animals

TOP 16 deadly and poisonous fish on Earth


Salmon Infectious Anemia (Anaemia infectiosa salmomdae), a viral fish disease characterized by damage to the blood-forming organs of the central nervous system and the development of severe anemia. It is registered in the country of Western and Eastern Europe and in the USA, in the USSR (sporadic cases).

Pathogen Salmon Infectious Anemia - unclassified virus. The source of the causative agent of the infection is sick fish, their excretion, and caviar. The reservoir of the pathogen is the corpses of dead fish, an infected bed and water from a dysfunctional reservoir. All age groups of rainbow and brook trout, as well as Caspian salmon, are susceptible to infection. In manufacturers, the disease worsens in the pre-spawning period and ends in their death. An incubation period has not been established. The disease is acute and chronic. In the acute course of the disease, the fish is sluggish, refuses to feed, floats to the surface of the water, stands motionless near the shore and does not respond to external stimuli. On the body - diffuse dark spots, exophthalmia, necrotic decay of fin membranes are manifested. Before death, the fish makes rapid helical movements or stands in the water column head down and often dies in this position. In a chronic course, hemorrhage into the iris of the eyes, significant exophthalmia and loss of one or both eyeballs from the orbits are observed, and the skin is dark purple in color. The chronic course of the disease lasts 1-3 months. Most diseased fish die. At autopsy in acute course Salmon Infectious Anemia accumulation of dark brown liquid in the abdominal cavity, grayish-dark mucus in the stomach, and pityriasis mass in the intestine. The intestinal walls are hyperemic, the anus is protruded, yellow mucus is secreted from it, the spleen is dark cherry in color, it is reduced, the liver is yellow or gray-yellow with hyperemic areas, the heart muscle is pale, flabby. Hydropericarditis is noted. The kidneys are dark gray, with white stripes on the surface, loose, swollen, easily destroyed. In the brain hemorrhage. Blood is pale pink, slowly coagulates. The muscles are white or yellow, sometimes with separate hemorrhages. In chronic course Salmon Infectious Anemia manufacturers sometimes also observe severe hyperemia of the ovaries. The diagnosis is made on the basis of epizootological, clinical and pathological data, histological studies (detection of eosinophilic Taurus inclusions in the kidneys, liver and intestines) and the results of bioassay on susceptible fish (salmon, trout).

The treatment has not been developed. Prevention is based on the timely implementation of a complex of veterinary and sanitary, fish-breeding, reclamation and zootechnical measures.

Bull Shark

Bull shark - the most terrible fish that can be found in the seas and oceans. It belongs to the order Karhariformes and lives in the tropical and subtropical latitudes of the oceans.

A blunt shark is tolerant to different salinity of the water and sometimes enters rivers. Most often attacks in the Bahamas area. The attack of the bull shark in 90% of cases ends in the death of a person, this is a very aggressive predator. First, she hits her victim, which makes her lose consciousness, and then bites her. The weight of the fish exceeds 250 kg, and in length it can reach 4 m.

Great White Shark

The largest deadly fish in cool ocean waters. Its size reaches 6.5 m and its weight exceeds 1 ton! Huge jaws, a powerful tail and a speed of over 40 km / h make the white shark one of the deadliest fish on the planet. And she can smell a drop of blood at a distance of up to 5 km.


Warts are found in warm oceanic waters. Fish skillfully disguises itself as stones and often attacks inattentive people. Poisonous thorns are located on her body - one dose is enough to poison a person. There is no antidote to her poison.

Electric eel

Fish is found only in the rivers of Latin America, including in the Amazon. Outwardly similar to ordinary eel, but different in size and thickness. It has a unique system of organs capable of generating a discharge of up to 600 V, which instantly paralyzes production. People who get a similar electric shock can drown and die.


The creature is found in warm waters, lives at a shallow depth and spends a lot of time at the bottom, buried in the sand. In length, adults reach 2 m, and in weight - 30 kg. On the tail is a sharp spike - a weapon of defense and attack. It is with them that fish pierces the skin of a person and releases deadly poison. As a result, paralysis develops, due to which the victim dies.

Great Barracuda

A dangerous predator, whose weight reaches 50 kg and a length of 2 m. There are huge dangerous teeth in the jaw - up to 7 cm long. Barracuda instantly reacts to metal objects that shine in the water and attacks the target. It is found on the Caribbean islands, in the Mediterranean Sea and in the waters of the Atlantic. In rare cases, you can see the barracuda in the Indian Ocean.

Tiger fish

It lives in the waters of Africa and South America. The closest relative of piranha with huge teeth, also very aggressive. A flock that attacks a person can kill. Tiger fish alone can cause severe injuries.

Fish found in the warm rivers of India and Nepal, has a middle name - the devilish catfish. It has an aggressive character and huge size, often attacks people. Cases of hunting devilish catfishes for people have been recorded: after an attack, a fish drags a person under water.


Predatory fish, which can be found mainly in Australia, off the coast of China, Japan. Very beautiful, small fish, whose weight barely reaches 1 kg. The fins contain poisonous needles that poison and cause severe pain. Rapid paralysis can occur, including the respiratory system. If the victim is in the water, then it is likely to drown.

Brown puffer

Dangerous puffer fish living in the water column of the Northwest Pacific Ocean. It rarely exceeds 80 cm in length. But the danger of this fish is not that it attacks a person, but that it is used in cooking: dozens of people are poisoned with puffer dishes every year, but it has not yet been banned in Japan.


One of the most famous freshwater predators that attacks humans by nesting in a pack. Very fast fish with sharp teeth. In a few minutes, a flock of piranhas is capable of stripping meat to bone from one person. It differs in miniature dimensions - up to 15 cm in length - and colossal bloodthirstiness.

Surgical fish

A tropical inhabitant whose length can reach more than 1 m. It is found in the waters of the Pacific and Indian Ocean. The body is not equipped with poisonous needles or frightening teeth, but there is a sharp tail. They surgical fish hooks the victim, killing in 1-2 blows. Swimming in the ponds where this predator is found is not recommended.


The creature lives mainly next to coral reefs in tropical waters. When threatened, it turns into a huge ball covered with dangerous spikes. Inside them contains poison, as in special vessels throughout the body. If a person stumbles upon a sea urchin, he may die. Fish-hedgehog is not very mobile, therefore, it is often found in waters that are not characteristic of its habitat.


The small parasite fish is slightly larger than the leech. It penetrates the gills of larger marine inhabitants and parasitizes on them. It has a transparent body, so it is often overlooked. It feeds on blood, there are few cases of attacks on people.


A fairly large marine predator - in length reaches 1 m or more, and in weight - 15-18 kg. In the lower jaw there are long fangs with which the hydrolysis kills the victim. It feeds on other predators, including piranhas. It is very difficult to catch this fish, so it has become a favorite among sports fishers.

Saw fish

A huge marine inhabitant - grows up to 7 m in length, of which 3 m is a dangerous knife. People are not intentionally attacked. However, the fish has poor eyesight and can attack someone who came into its territory. Saw blows are very traumatic and even fatal. But there are very few of these fish left - they are under protection.


The cause of injuries can be a showdown between males and fights between fish of different species. Therefore, it is important that there are enough females in the aquarium. The optimal ratio is three girls per boy. In addition, fish can hurt themselves on the sharp edges of equipment, decorations, and soil.

In order to avoid infection and the appearance of white plaque on the surface of the wound, hydrogen peroxide (5-10 ml per 20 l) or iodinol is introduced into the water. You can also use streptocide.

Chlorine poisoning

Swordfish are very active and consume more oxygen than many other fish species. They often have to breathe and pass more water through their gills. As a result, very often these fish are poisoned by chlorine, which is contained in water.

  • mucus on the gills
  • changes in behavior (swordsmen become twitchy and lethargic),
  • the gills turn unnaturally yellow
  • fish jump out of the aquarium.

Methods of prevention and treatment:

  1. Before pouring water into the aquarium, it must be defended for two days or use a water conditioner and mix the water well.
  2. Buy a chlorometer, and check the amount of chlorine in the water. Norm - 0.03-0.05 milligrams per 1 liter.
  3. After the first signs of poisoning appeared, transplant the swordsmen into clean water.

Lack of oxygen

Sword-bearers swim near the surface and trap air in their mouths. If the aquarium is very carbon dioxide, then snails also begin to float to the surface. As a result, the swordsmen begin to choke, stop reproducing, refuse food. In order to correct the situation, aeration equipment is installed in the aquarium, the population of the aquarium is reviewed.

Ichthyophthyroidism (semolina)

The cause of the disease, as a rule, is improper conditions of detention, in particular sudden changes, or low temperature. A swordsman itches on stones, soil and all protruding objects. A rash resembling semolina appears on the body. If a fish starts to lower its fins - this is also one of the symptoms of the disease.

The cause of the disease is infusoria is equi-ciliary. It is often found in aquariums, but only individuals with low immunity become ill. An effective treatment for this disease does not exist. The only way to improve the situation is to gradually raise the water temperature to +26 and protect the swordsmen from stress. The body of the fish must cope with the disease on its own.


The cause of this disease is a very small creature, the parasite chylodonella.

  • decreased activity (the sick individual freezes in place and sways slightly),
  • the fish’s appetite decreases
  • the fin, which is located on the back, descends, and if you look closely, then under it you can reveal a raid of gray-blue color.

As a rule, swordsmen suffer from chylodenosis most often of all other species. Even if different types of fish live in the aquarium, parasites often settle only on swordsmen.

Chylodenosis is eliminated with the help of antiprotozoal drugs. The success of treatment depends on the stage of the disease. The sooner you start treatment, the higher your chances of survival. All diseased individuals should be quarantined.


This disease is dangerous not only for swordsmen, but also for other inhabitants of the aquarium. Sick fish ceases to actively eat food, loses activity. If the disease progresses, the swordsman is poorly oriented in space and loses the ability to swim normally. Sometimes abscesses, black dots or ulcers appear on the body of the fish. The swordsman lies at the bottom and refuses food.

In the very early stages, the problem can be solved with copper sulfate, tripoflavin, or monocycline. With advanced stages, the fish die.

Fin rot

This bacterial infection is common among swordsmen. It affects fry and immunocompromised adults. External signs of the disease are turbidity and destruction of the fin. A disease can be cured only if the damage has not spread to the body of the fish, otherwise the rot will primarily affect the nervous system.

If you notice the first signs of the disease in time, then the treatment will be successful. It is enough to place all sick swordsmen in a separate container and use a weak solution of methylene blue instead of water. The liquid should have a pale turquoise color.

A good effect is given by salt treatment. Dissolve 1 tablespoon in 10 liters of water. This will not harm healthy swordsmen, and the number of cases will decline.

If these measures do not help, then it is worth using chloramphenicol. Enough 1 crushed tablet per 20 liters of water.

After the signs of the disease have disappeared, the swordsmen must be quarantined for at least another 5 days.


Typically, dropsy occurs as a result of exposure to a viral or bacterial infection, poor nutrition, the presence of parasites, temperature extremes, and a high content of nitrites or nitrates in the water. Swordsmen become infected from contact with their fellow tribesmen, soil or live food.

External signs of the disease:

  • apathy,
  • the swordsmen are at the bottom
  • often breathe
  • swollen abdominal cavity
  • the scales swelled and sticks out in an unnatural way,
  • often hang in one place.

To save the pet from excess fluid, Epsom salt is added to the water (1-2 tsp per 40 l of water). Also, the problem is eliminated with the help of the following drugs: potassium permanganate, maracin, chlorafeminicol, bicillin.

Infection is often a danger to people, so when working with fish, wear protective gloves.

The fish has swollen eyes

The causes of the disease are trauma or bacterial infection. Also, improper conditions of detention can often lead to this result. Often, as a result of non-compliance with all conditions, nitrites, nitrates, and ammonia accumulate in the water. To eliminate the problem, it is enough to test the water, and if the indicators exceed the norm (and usually it is), the liquid should be replaced and the nitrogen concentration should be monitored in the future.

Features of using live food

If live larvae are used as food, then they can also be a source of infection or contain parasite larvae. To protect the pets, it is worth putting the bloodworm and tubule for several days in the freezer. During this time, the parasite eggs, if they do not die, then noticeably weaken, and will not pose a great danger. Also, live food can be disinfected with a solution of potassium permanganate or methylene blue.

Plant preparation

All new plants are also treated with a weak solution of potassium permanganate.

For successful breeding of swordsmen, it is necessary to ensure the correct temperature conditions, clean water with a high oxygen content, as well as a varied diet. These are active fish that defend their territory and females. You should control the number of individuals and avoid conflicts between them.

Infectious resistance

Infectious resistance Resistance, or resistance, to antibiotics is a hereditary phenomenon. From a stable staphylococcus cell, offspring resistant to them arises. In 1959, a special form of resistance was discovered, transmitted to other microorganisms and

Infectious resistance

Infectious resistance Resistance, or resistance, to antibiotics is a hereditary phenomenon. From a stable staphylococcus cell, offspring resistant to them arises. In 1959, a special form of resistance was discovered, transmitted to other microorganisms and