Trout is a typical representative of the salmon family, which includes anadromous and freshwater fish. The closest “cousin” relatives are sea trout, Lenka, Pacific salmon and Pacific trout. The checkpoint is called brown trout, freshwater (residential) – the trout.
Trout exist in nature in various forms that differ from each other in appearance, existence and ecology. Taxonomy currently, there are 6 subspecies, of which the waters of Russia and the former Soviet Union is home to five: 4 passing and 1 lake. Another subspecies lives in the rivers of the Aral sea basin and the last in the waters of the Mediterranean sea, in the sea comes out.
To confuse the issue of systematics and kinship of many “comgeorgia-trout” forms the crucial role played by the acclimatization and breeding of brown trout in artificial conditions. Earlier trout and trout considered as separate groups of fish. For example, for a long time scientists held the point of view of Linnaeus, according to which brook trout and brown trout were the special types. The falsity of this statement pointed out the following fact: in New Zealand for acclimatization in the local rivers was brought to the trout. After a while some get the trout slipped into the lower reaches of the rivers and the sea and turned into a checkpoint trout!
At the present time can be considered a proven fact the phenomenon of turning a passing trout, brook and lake trout at each other! The European brook trout, sometimes even slipping into 300-700 km. down the river, leaving in estuarine space of the Mediterranean and Adriatic seas, as if making attempts to turn into the checkpoint form. With the release of young foreleg from hatcheries in the Baltic sea acclimatizate easily acquire a silvery color and return to spawn in the guise of a passing trout.
This very plastic (changeable), the fish body color, its shape, and even biological indicators of different water bodies of the European-Asian part of the continent vary greatly. There are instances of very light and almost black, short, thick and elongated.
Unlike the salmon the salmon the number of scales in a transverse row from the end of the adipose fin to the lateral line 15-18, 105-132 lateral line scales, Gill rakers 13 to 18, there is ugarcovici. The smallest body height (height of caudal peduncle) not more than two times in length of caudal peduncle. Body above and below lateral line covered with numerous black spots that have a light halo. On the sides of the body there are red spots. In rivers the colouring is brownish on the back with a silvery sheen on the sides. In large lakes and estuaries, trout has a dominant silver color.
The size of the fish vary depending on habitat conditions in streams in residential trout (trout) can be no more than 25 cm in large lakes up to 1 m, weight up to 8-13 kg. Migratory brown trout are larger, up to 1.4 m.
Baltic trout usually has a size of 30-70 cm and a weight of 1-5 kg, although there is evidence of catching trout, which weighed 23.6 per kg. Ciscaucasian trout are much smaller – 1.9 to 7 kg. Caspian brown trout – the giant among salmon having a mass of 51 kg, but now it does not exceed 12-13 kg. Due to the huge size and mass, and despite the great similarity with salmon, taxonomists considered a kind of Caspian trout is a subspecies of salmon. Only recently (1980s) established for the specific structure of the embryo in the egg and the chromosome number that is much changed in the evolution of the form of trout.
The maximum known age for anadromous trout as well – 19 years, for lake trout is 20 years old. The entrance and freshwater species widely inhabits the rivers of Northern Eurasia and lakes with cold water. Juveniles feed on small crustaceans and insect larvae in the river and usually spends 3-4 years (sometimes more). In the sea lives 2-3 years, but sometimes comes back after a year. At sea, feeds on fish and large crustaceans. Living forms in the lake (trout) is also often switch to a predatory way of life.
According to the way of life of a trout refers to the fish with a wide range of food. She who preys, but do not forget about the food flying insects, often in the stomachs of brown trout find a large number of aquatic invertebrates. In search of the prey the fish loitering in the water column, adhering to the upper layers of the water.
Often trout forms different kind of shapes. For example, in lake Ohrid, located on the border of Macedonia and Albania, there are two forms of brown trout: a large (up to 10 kg), predatory trout, previously identified as a separate species – the staircase and the small silvery fish that feed on plankton, so it is unlike the cousin, the predator that it had to be a separate genus with one species – Belize. A similar pattern is observed in Dagestan lake Asanam inhabited by two different forms of the same species – predatory and non-predatory.
In General, the trout is a fish pass, spawning in the rivers. The process of spawning brown trout is similar to that in salmon. Depending on the location, distribution, timing of spawning vary from September to February. Spawning occurs in shallow rapids and river sections, caviar or vymatyvayutsya on the rocks and coarse sand, or buried in pits. The average fecundity of trout from 7 to 12 thousand eggs, caviar, orange, large, reaches 5-6 mm. in diameter. Spawning grounds are located in the upper reaches of rivers and in the middle reaches. Spawning throughout life, from 4 to 11 times. Hatching of larvae occurs in 6-8 weeks.
The homing and breeding plumage have brown trout less developed than in salmon. Like salmon, trout comes to spawn with different status, sexual products and, depending on this, it spawns, or in the year of entry, or the year after. It is believed that where there is a checkpoint and residential forms of trout, they make up one flock spawning together. In passing trout population is dominated by females, a lack of males kompensiruet through the living forms of the char, where individuals “male sex” live in the majority.
Another difference trout from salmon during spawning trout does not stop eating. Feeding and growth of fry of trout occurs in river conditions. Fry it feeds in the river, from one to seven years, and then, upon reaching a length of 20 cm, is sinking into the sea.
In Russia inhabits the basins of the Barents, White, Baltic, Black and Caspian seas. Numerous on the Kola Peninsula and in Karelia. In the Neva river is extremely rare, is in the Narova, Luga, Gulf of Finland. In the white sea and Barents sea coast goes to Czech lips, but in the Mezen and Pechora. View acclimatized in many countries, including in the Americas.
In Central and North America of trout was not, but her appearance in American waters took place thanks to the efforts of man. This fish was successfully held on naturalization and settled down, and in the process of development of rivers and lakes of America, there was such a variety of forms of trout, which in the XIX-th – early XX-th century American taxonomists have described more than 30, of which currently only recognizes two independent.
Valuable commercial species. The object of sport fishing and fish farming. All subspecies of trout has dramatically reduced their numbers listed in the Red data book of Russian Federation 2001.