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The name trout refers to a number of forms and varieties of freshwater fish that represent the salmon family. There are 7 active genera in this family and trout are included in 3 of them: char, salmon and Pacific salmon.
Trout fish: description
Trout are distinguished from other species diversity of the salmon family by a number of common features. They have a relatively large body, on the 10th part of which, located under the lateral line and in front of the vertical, if it is lowered from the region of the dorsal fin, there are from 15 to 20 scales. Above the anal fin, the number of scales reaches 13 to 19 pieces. The body of the trout is practically compressed on the sides, and the short snout is distinguished by a characteristic truncation. In its mouth there are many teeth, which is very characteristic of a predatory fish.
Appearance
Depending on the specific species, the appearance of the trout also differs. For example:
- Trout brooch. It reaches a length of more than half a meter, and in the 10th year of life it can reach a weight of about 12 kg. It is considered a fairly large representative of this family, with an elongated body shape, covered with rather small, but at the same time, scales that are tightly adjacent to the body. The brook trout has small fins and a large mouth, studded with a large number of teeth.
- Lake trout. This representative has a more powerful body compared to the brook trout. The head is compressed laterally, so the lateral line can be easily seen. The sides and belly are light in color, while the back has a characteristic red-brown tint. Numerous dark spots, not large in size, can be seen on the body of lake trout.
- rainbow trout. This representative of the salmon family has a rather elongated body. Adult specimens gain weight of about 6 kilograms. The body is covered with medium-sized, but rather dense scales. It differs from other types of trout by the presence of a pink stripe located on the belly of the fish.
Depending on the habitat conditions, different types of trout have an ambiguous color. As a rule, the color of the back of a trout has a dark olive tint, with the presence of a greenish color.
Interesting fact! A well-fed fish is always more monotonous in color and has a minimum number of spots. As a result of some observations, it has been established that the change in body color mainly depends on the change in living conditions when the fish moves from its natural habitat to an artificial reservoir.
Trout lifestyle
Each species of trout is characterized by unique habits, which is associated with weather indicators, with the uniqueness of habitats and the peculiarities of the seasons. Representatives of brown (local trout), as a rule, are able to make long movements. At the same time, the fish does not carry out global migrations, like sea trout, but actively moves upstream or downstream in the reservoir, especially during spawning periods, as well as in the process of searching for food and new habitats. This is also characteristic of lake trout.
At the end of spawning, in cold weather, the fish goes downstream to traditional habitats, adhering to areas where springs flow and there are deep-sea places, constantly being almost at the very bottom. In spring flood conditions, fish move closer to high banks, which provides them with food, but with the advent of summer heat, trout tries to go under waterfalls, to a considerable depth and to areas with whirlpools. She seems to demonstrate that she is a cold-loving fish. In such areas, the trout stays until the onset of cold weather, when the water temperature becomes more comfortable for the trout.
How long does a trout live
The longest lifespan is observed in lake trout. She can live for decades. As for river trout, its life expectancy is about 7 years.
Interesting to know! The age of a trout can be recognized by the growth rings located on the scales. Every year, fresh hard growths appear along the edges of the scales, indicating that the fish has lived for another year.
Sexual dimorphism
Adult males can be easily distinguished from adult females by a number of characteristic features. Firstly, males are somewhat smaller and have a larger head, as well as a significantly larger number of teeth. Secondly, over time, a characteristic upward bend appears on the lower jaw of males.
Trout species
There are main species and subspecies of trout, which represent several genera of the salmon family. These types include:
- The genus “Salmo” represents: Adriatic trout, brook trout, lake trout, Turkish flathead trout, flying trout, marble trout and Amudarya trout.
- The genus “Oncorhynchus” represents: Arizona trout, Clark salmon, Biva trout, Gil trout, Golden and Mikizha trout.
- The genus “Salvelinus” represents chars: American char, Salvelinus fontinalis timagamiensis, Bighead char, Malma, Lake Christivomer char, and Silver char, which is considered an extinct species.
If many factors are considered from the standpoint of genetics, then lake trout is characterized by the highest heterogeneity among representatives of vertebrates. For example, the British wild trout population has such a number of variations that it is much larger than all people living on our planet.
Interesting to know! Despite the fact that the lake and rainbow trout belong to the “salmon” family, they are descended from the same ancestors belonging to different genera and species. This happened because millions of years ago they split into 2 separate groups.
Range, habitats
Trout lives in many large water bodies on our planet. The main condition for existence is crystal clear, cold water, with an optimal concentration of oxygen and a constant influx of fresh volumes of water. Therefore, it is found both in lakes and in rivers, including mountain rivers. Huge populations of trout have been recorded in fresh water bodies of the Mediterranean, Western Europe, America and Norway. As a rule, trout is an object for professional, sport and amateur fishing. This is due to the fact that this fish is also strong, which gives a lot of pleasure when playing. In addition, the fish is characterized by excellent gastronomic data. It forms the basis of many haute cuisine dishes, although it is not problematic to cook it at home.
Lake trout prefer to live in clear, cool waters, where they form numerous schools that stick to deep water areas. Brook trout is characterized by the fact that it is able to live in both fresh and salt water. The brook trout is an anadromous species of trout. This is due to the fact that she fattens up in the seas, and goes to spawn in the upper reaches of the rivers, while overcoming tens or even hundreds of kilometers.
Brook trout does not form numerous flocks. Prefers to be in areas where the optimal amount of oxygen and a constant influx of clean, cold water.
Rainbow trout is found off the coast of the Pacific Ocean, including off the coast of the North American part of the Americas in reservoirs with clean fresh water. Representatives of this species have most recently been forcibly moved to the waters of Australia, Japan, New Zealand, Madagascar and South Africa. Here they successfully settled down. Rainbow trout do not tolerate active sunlight, so during the daytime they try to hide in their shelters, which are massive stones or snags.
In Russia, some representatives of salmon are found within the Kola Peninsula, as well as in water bodies that are part of the basins of the Baltic, Caspian, Azov, Black and White Seas. In addition, they are found in the reservoirs of the Crimea, in the Kuban, in the Onega, Ladoga, Ilmen and Peipsi lakes. Moreover, trout in our time is bred artificially and on a rather serious scale. Particular attention should be paid to the fact that in our time paid reservoirs began to grow like mushrooms after rain, where various types of fish are grown and bred, including trout.
TROUT FISHING IN MOUNTAIN RIVERS
Diet
Trout fish is a predatory fish whose diet includes various objects of animal origin. At the same time, she easily eats her smaller relatives, as well as caviar of other fish species. In spring, in flood conditions, trout stay close to steep banks and feed on bugs and worms, which are washed from the banks by water.
In summer, this fish tends to avoid areas where the water warms up quickly, so it stays within waterfalls, whirlpools and deep areas. Trout feed either early in the morning or late in the evening.
With a strong thunderstorm and active precipitation, as a rule, flocks of trout rise from a depth closer to the surface of the water, where they find living objects for food. The trout grows quite quickly as it feeds on any living things it finds in the water column or at the bottom. Starting in spring and all summer, this fish feeds on insects that fall into the water for one reason or another.
Breeding process
Trout spawn at different times, depending on the species and other factors affecting the life of the fish. In habitats where the water is too cold, trout spawn quite early. In the conditions of Western Europe, this fish can spawn in winter, and in the Kuban – in October. In December, the Yamburg trout spawns. According to experts, the fish spawn at night, with a full moon. And yet, the main spawning process falls on the period when the sun has just set and before the period of complete darkness, including early in the morning, when the sun has not yet risen.
Trout are ready to spawn when they reach 3 years of age, although under certain conditions, males are already ready to fertilize eggs at the age of 2 years. Adult individuals do not spawn annually, but after a year, while the number of eggs is several thousand pieces. When a trout spawns for the first time, the number of eggs is relatively small, about 500 pieces. In a year, they will be able to lay no less than 1 thousand eggs. Going to spawn, the trout changes its color to a dirty gray, while the reddish spots turn pale or disappear altogether.
To lay eggs, females choose special places where the bottom is strewn with small pebbles, although if there are no suitable places, then the female can spawn on the bottom, with large stones and other, completely uncomfortable objects. Before spawning, she uses her tail to make a small depression at the bottom, while she cleans the pebbles from various debris. The female is immediately accompanied by several males, but the male with the most mature milt fertilizes the eggs.
Interesting to know! The female chooses a partner according to various, including visual signs. This allows the trout to form healthy offspring with the best characteristics and resistance to external negative factors.
Trout has a rather large caviar, which is distinguished by an orange or reddish tint. Due to the fact that trout eggs are constantly bathed in clean, cold and oxygenated water, after a while, fish fry appear from the eggs. If there is enough food, in the form of daphnia, chironomids and oligochaetes, then the fry develop quite actively.
Natural enemies of trout
Already at the stage of development of eggs, danger awaits them, since burbot, grayling, as well as trout individuals that have not reached puberty can eat caviar. When born, up to 90% of individuals do not survive in the first year of life. After that, the mortality rate drops to a level of about 50%. In addition, seals and bears, as well as birds, hunt trout. If everything is accurately calculated, then no more than 2,5% of the individuals that emerged from the eggs survive until the moment of spawning.
Fishing value
Trout, like many other representatives of the salmon family, is considered a valuable commercial fish. It is in demand, especially in the restaurant business. Therefore, its catch in large commercial volumes has led to the fact that its population is noticeably declining.
Currently, humanity is puzzling over how to increase the population of the salmon family. For this, various trout farms, cage farms and fish farms are being created, where this fish is grown under artificial conditions. Some species of trout were domesticated, after which they were able to live in artificial conditions for several tens of generations. The undisputed leader of this process today is Norway.
Species status and population
Trout is a cold-loving fish, so it is quite sensitive to global climate changes, especially in the direction of rising water temperatures. With an increase in water temperature, there is a negative impact on the fish, or rather on the stages of its life, and such an important stage as spawning. In addition, serious damage to the number of trout is caused by uncontrolled fishing, especially of reproductive individuals.
It should also be noted that the fish is sensitive to the purity of the water. This is especially true today, since the water resources of our planet are being polluted at a high rate, which also causes serious damage to the number of valuable commercial fish, including trout.
Based on the research conducted by scientists, we can safely say that the artificial increase in the trout population leads to an increase in the number of adults that have not reached the average size, and have not gained optimal weight. Various artificial barriers created by man in the form of dams, drains and overpasses lead to the fact that fish are not able to physically get to their natural spawning grounds. Since she cannot spawn in the natural conditions predetermined for her by nature, this leads to a decrease in the survival rate of eggs. Considering how many eggs survive in the natural environment, this is a real disaster.
At present, the trout has an average conservation status. In other words, scientists have already paid attention to it as a species that may disappear. This is also indicated by the fact that some countries have imposed a ban on the commercial catch of this fish. Restrictions also exist for amateur fishermen: they are allowed to catch trout only under special licenses.
Trout fish is a unique fish in its value. Its meat is rich in a lot of useful substances that are simply necessary for a normal, healthy human life. Eating seafood is permissible for any category of people, with the exception of those whose body does not tolerate such products.