Trout is a commercial fish that can be either lake or migratory. However, its freshwater variety is often called trout. It is noteworthy that this individual is able to quickly adapt to different living conditions. Therefore, it has a wide distribution area. If necessary, sedentary brown trout can move to the sea, while migratory trout, if there is a sufficient amount of food, remains in a freshwater body of water.
Description of the fish
This fish is considered a typical representative of the Salmon family. It belongs to the Trout species. Interestingly, the name of the fish comes from the Sami word “kuu”︢dz︣a".In Finnish it later became "kumsi". Fishing for this fish has been going on since ancient times. However, it was only in 1974 that Finland began to keep records of the catch of such individuals separately from other members of the family.
Appearance
There are a number of varieties of trout - Black Sea, Baltic, Caspian, Eisenam, Cis-Caucasian. However, they have similarities in appearance. The characteristic features of this type include the following:
- large head;
- an abundance of small spots on the body, fins and head;
- small scales of cycloid type;
- large tail, on which there is a faint notch.
The brown trout fish differs from its close relatives in its large head, on which there is a wide mouth. The mouthparts of this individual are slightly directed upward. This suggests that it absorbs food in the water column. The fish's mouth contains small, sharp teeth. They are not capable of seriously damaging the victim, but reliably hold the prey.
The upper jaw bone of the brown trout extends beyond the vertical of the eye. This trait helps distinguish this species from other members of the Salmon family. In adult males, the jaws acquire a curved shape. However, this trait is not as pronounced as in salmon or coho salmon.
There are many small round spots on the body, on the sides of the head and on the upper fin. In young individuals they are distinguished by a dark shade, and in mature ones they are red or pink.
The fish that lives in small lakes and rivers are distinguished by golden scales. Visually, it resembles a brook trout. Individuals that live in the sea are characterized by a silvery color. During the spawning period, males become darker. At the same time, red stripes appear on the body and gills.
Brown trout are characterized by smaller scales than salmon or sockeye salmon.It sits tightly on the skin, which provides the fish with protection from damage that may occur when interacting with stones and other underwater objects.
The tail fin of brown trout does not have a pronounced V-shaped notch. This is the main difference from salmon and coho salmon. Thanks to the presence of a massive tail and a torpedo-shaped body, the predator can hunt in conditions of intense currents without significant expenditure of energy and swim long distances during sea migrations.
Trout, which lives in fresh water bodies, reaches a length of 70 centimeters. Its weight is no more than 5 kilograms. Marine individuals are characterized by larger sizes. The largest fish was caught in the Baltic Sea. Its length exceeded 1 meter, and its weight reached 12.5 kilograms.
Habitat
Trout lives in the seas, rivers, lakes and mountain streams of various countries. It is found in the Black, Okhotsk, Caspian, Aral and other seas. A significant population of brown trout is observed in the rivers of Sakhalin. This island attracts many wild trout fishermen. Previously, these individuals lived in the Sea of Azov, but the population has now disappeared. There are small numbers of brown trout in the Gulf of Finland. However, it does not enter the Neva.
Different types of brown trout spawn in European rivers. These individuals are also found in cold mountain streams of Dagestan, Greece, and Spain. They can be found in Italy, Morocco, Portugal, France and many other countries of the world.
For normal functioning, brown trout require a lot of oxygen. Therefore, most often it lives in fast mountain rivers, streams and cool lakes. This individual does not tolerate too warm water. Suitable temperature indicators for it are at +15-20 degrees.Even during the spawning period, this fish does not move to warm water bodies, but to places with cool water.
The fish is highly adaptable. She chooses to live in conditions that are most suitable for maintaining her population. Brown trout rarely stay in one place for more than 2-3 years. She can leave the reservoir, and after 1-2 years return to it again.
Lifestyle Features
Brown trout differ in varieties. It can be Black Sea, Baltic, Caspian. Regardless of the species, this fish leads a similar lifestyle. Brown trout is a predator that spends most of its time hunting. She attacks schools of fish in coastal waters and hides in the thickets, waiting for crustaceans. Sometimes this individual attacks quite large fish.
Wild trout hunt throughout the whole year. Its hunting instincts do not become less pronounced even during migration before spawning. At the same time, the fish searches for food alone. Brown trout tend to form schools only when moving to spawning grounds.
If other representatives of the Salmon family spawn only once in their lives, then brown trout do this 4-11 times. Moreover, it is capable of reproducing at any time of the year, with the exception of winter. Both sedentary and migratory fish take part in spawning. Females dig small depressions in river rapids and lay fertilized eggs there, covering them with pebbles. The clutch contains 3-5 thousand large eggs, which reach a diameter of 5 millimeters.
Immediately after fertilization and laying eggs, males and females return to their normal habitats.If in some species of fish the males remain to guard the eggs until the fry appear, then the brown trout have a different behavior and do not participate in the further fate of the offspring.
During the spawning period, many representatives of the Salmon family stop feeding, and after laying eggs they die. Brown trout are considered an exception to the rule. During the spawning period, she does not change her diet. Immediately after laying eggs, this fish begins to lead a normal lifestyle. If for some reason the fish does not return to the sea, it is easily able to adapt to life in a fresh water body.
If we talk about the fry, they hatch from the transparent shell after approximately 44-45 days. Small fish feed on insect larvae. Their diet also includes adults and amphipods. The fry spend the first years of life in fresh water bodies. After this, they move to the sea and remain there until puberty. This takes 1-4 years. During this time, the young animals consume the fry of other fish and small invertebrates. After reaching sexual maturity, the fish move to the river to spawn.
Diet
The diet of brown trout is directly influenced by its habitat. Fish that gain weight in the sea eat the following foods:
- shellfish;
- sea worms;
- crustaceans;
- small fish - smelt, herring, sand lance.
Lake and river trout species mainly consume small fish. They also eat various types of invertebrates, aerial insects and their larvae. If there is a lack of food, brown trout may partially eat algae. This behavior is more typical of young fish, which weigh no more than 200 grams.
Varieties
Brown trout are found in different places.Depending on their habitat, several types of such individuals are distinguished, each of which is characterized by certain characteristics.
Black Sea
This subspecies lives in the Black Sea. Previously, fish were found in the Sea of Azov, but today this population has disappeared. Black Sea trout are resident and migratory. Representatives of the migratory species go to spawn in rivers and feed in the sea. They reach a length of 75 centimeters and weigh 3.6 kilograms. Representatives of the residential form spend their entire lives in the river. Their length is 25 centimeters and their weight does not exceed 1 kilogram.
Black Sea trout go to spawn in the fall. Sometimes it breeds in January-March. This fish enters only the largest rivers to spawn. The fry remain there for more than a year. After that, migratory species move into rivers, and freshwater ones remain there. The migratory form of the Black Sea trout is today on the verge of extinction. That's why it was included in the Red Book.
Baltic
This species of brown trout lives in the basins of different seas - the Baltic, White, Barents. A distinctive feature of the Baltic species is its silver color. This fish is characterized by dark gray fins and tail.
In the post-Soviet space, fish go to spawn in October-November. In the rivers of Western Europe, this individual begins breeding in November-December. The juveniles that emerge from the eggs spend 3-7 winters in fresh waters. In lakes and rivers, Baltic fish consume larvae and insects. In the sea, small fish and crustaceans become the basis of its diet.
Caspian
This subspecies entered the Caspian Sea when it connected with the Azov Sea.Caspian trout differs from other varieties in its large size and low caudal peduncle. These individuals are capable of increasing their mass up to 51 kilograms.
This migratory fish breeds in rivers that have a pebble bottom. Spawning lasts from October to January. In this case, the water temperature is +3-13 degrees. This subspecies is widespread in the Caspian Sea and in the rivers that flow into it. It is concentrated mainly in the southwest of the sea.
Eisenamskaya
This species lives in Lake Kezenoyam, which is located at an altitude of 1850 meters above sea level. Eisenam brown trout spawn in cold, clear water. Moreover, reproduction is extended over time and continues for most of the year.
Such trout can be small or large. The first variety grows up to 26 centimeters in length and weighs 350 grams. It has small black and large red spots on the sides. The dorsal fin of such individuals is black-spotted, and the adipose fin is red-spotted. Large trout grow up to 113 centimeters and weigh up to 17 kilograms. It is characterized by a dark color. These individuals prefer to lead a predatory lifestyle.
Pre-Caucasian
Cis-Caucasian trout reaches a length of 40 centimeters and is capable of gaining a weight of 900 g. This fish has no commercial value, but is very popular among sports fishermen.
This fish lives in the Caspian Sea basin. For spawning, it goes to the reservoirs of the western coast, with the exception of the Kura. Previously, this fish was distributed everywhere. Recently, there has been a decrease in the number of Cis-Caucasian trout. This is due to changes in the ecological situation in the upper reaches of rivers and streams.
Water pollution and active fishing lead to a decrease in the population of such individuals.The Cis-Caucasian trout has completely disappeared in a number of regions - Vladimir, Yaroslavl, Saratov, Ryazan. It is no longer found in the republics of Mari-El and Mordovia.
Brown trout is a fairly common fish that belongs to the Salmon family. It is able to adapt to a wide variety of conditions, and therefore has become widespread throughout the world. However, some species of brown trout are now on the verge of extinction and require government protection.
