Chum salmon is a fish that belongs to the salmon family. It belongs to valuable breeds because of tender, tasty meat and very valuable caviar. It is often called a pass. Keta, in turn, is divided into several species, as well as two main races. All species that exist today are very similar in appearance, have a similar lifestyle and habitat. The exception is the Sakhalin chum salmon, which is mainly intended for breeding in artificially created conditions.
Origin of the species and description
The evolutionary stages of this fish are not well understood due to the lack of scientific data. Ichthyologists claim that the most ancient representatives of modern salmon existed in the rivers of North America about 50 million years ago. It was small in size and resembled a grayling in appearance and way of life. Due to the fact that the representatives of this family in the process of evolution had to survive in a variety of climatic conditions, they are very sensitive to changes in living conditions.
According to the rock paintings, we can say that the ancient ancestors of modern chum salmon already inhabited the Pacific Ocean about 10 million years ago. Some species of fish inhabited large lakes.
Many species of salmon simply died out. One of the most striking and amazing extinct species is the “saber-toothed salmon.” It was named so in honor of the saber-toothed tiger due to the presence of long fangs, uncharacteristic of fish. Their length reached 5-6 centimeters in large individuals.
The most favorable time in the history and evolution of chum came about 2-3.5 million years ago. It was during this period that salmon split into species, each of which occupied its own region of habitat.
Appearance and features
This representative of the salmon family spends most of his life in sea waters. In connection with these, it has a color typical of marine inhabitants: silver-bluish with a tint. In the back area, the fish has a darker color, in the belly area it is lighter. This color allows the fish to go unnoticed both in the water column and on the bottom surface. The chum salmon has a number of distinctive features and features.
Characteristic external features:
- a massive body of an elongated, elongated shape;
- somewhat compressed , tightened sides;
- the caudal and adipose fins are slightly shifted towards the tail and have from 8 to 11 feathers;
- the head is quite large against the background of a massive body and has the shape of a cone;
- the mouth is wide, in the mouth there are underdeveloped teeth;
- there are no dark spots and stripes in the mouth;
- the body is covered with medium-sized scales;
- there is a large solid caudal fin without notch.
Interesting fact: During the spawning period, the body shape and appearance of the fish changes dramatically. The body becomes larger and much wider, a hump forms in the back. The jaws become much larger, the teeth bend and become much larger and longer. The color becomes brown, yellow, greenish or olive. Purple or crimson stripes appear on the lateral surface of the body, which darken over time.
Some fish can grow to very large sizes. The length of her body can reach 60-80 centimeters, and her body weight can exceed 10 kilograms.
An interesting fact: According to official data, the maximum body size of a chum salmon was one and a half meters, and the mass 16 kilograms!
The fish that goes to spawn most often has a body length of about 50-65 centimeters. The body size of the summer chum salmon is smaller than that of the winter chum salmon.
Where does the chum salmon live?
The chum salmon spends most of its life in salt water reservoirs near the coastal zone. The main habitat of the chum salmon is the Pacific Ocean. It is customary to call the fish anadromous due to the fact that it actually lives in the seas, and goes to the mouths of the rivers for spawning. It is worth noting that for spawning, the chum seeks to find exactly the mouths of those rivers, from where she herself came out as a fry. Spawning occurs in freshwater rivers of the Far East, Asian countries, North America from California to Alaska.
The fish chooses the warm waters of the Pacific Ocean – the Kuro-Sivo undercurrent as regions for permanent residence and food.
Geographic regions of chum salmon:
- Okhotsk Sea;
- Bering Sea;
- Japan Sea.
Spawning occurs in river mouths. During this period, fish can be found in such rivers as the Lena, Kolyma, Indigirka, Yana, Penzhira, Poronaya, Okhota, etc. Keta is a shallow-sea fish. Most individuals live at a depth of no more than 10 meters. A significant part of the life of fish is carried out in food migrations. This period can stretch from 2.5 to 10 years.
Ichthyologists note that of all representatives of the salmon family that live in the waters of the Pacific Ocean, it is the chum salmon that has the widest habitat. In some regions of Russia, in particular, in Kamchatka and Sakhalin, chum salmon lives in artificial pools intended for breeding fish for industrial purposes.
What does chum salmon eat?
As the fish grows, the way of life of the fish changes. When it reaches the optimal size and body weight, at which it is relatively safe to exist on the high seas, it begins to lead a predatory lifestyle. During the fattening period, the fish needs a large amount of food, which can only be found in the sea.
After the fry grow up, they begin to gradually slide into the open sea. There they gather in groups and find quiet, secluded places where they hide until they reach the optimal size.
As they age, the fish becomes predatory and eats larger prey. During this period, a large amount of prey is required in order for the daily weight gain and growth to be in line with the norms.
Food base of adults:
- small flounder;
- sardines ;
Due to the fact that the fish lives in a flock, it also hunts in flocks. The specific coloration helps them not only to remain unnoticed by enemies, but also by their prey. Often it is enough for fish to simply freeze in anticipation of their prey. When the potential food comes as close as possible, the fish makes a dash and grabs the prey. Sometimes a flock of chum salmon simply crashes into a school of other fish and simply grabs everyone who did not have time to escape.
Peculiarities of character and lifestyle
It is very common for this representative of the salmon family to return to the places of birth. In almost one hundred percent of cases, during the spawning period, chum salmon swims to those places where she herself was born. It was this characteristic feature that became the main criterion by which ichthyologists divided the chum salmon into two categories according to the geographical principle – North American and Asian. Under natural conditions, their meeting is excluded.
The Asian taxon lives and breeds on the territory of the Russian Federation.
Depending on the habitat regions, ichthyologists have identified several subspecies of this species:
- Northern taxon;
After the fry turn into mature, adults, they do not remain in the rivers, like other members of the salmon family. To build up sufficient body weight for several years, he goes to the open sea. At first, immature individuals stay close to the shore in secluded places. Under optimal conditions and the availability of food, every day the body weight of the fish increases by about 2.5-3%. At the moment when the size of the fish reaches 30-40 centimeters, it goes in search of a region where there is enough food. Often such trips can last several years.
The chum fish is not a single fish, it gathers in numerous shoals. Most of them live in the northern regions of the Pacific Ocean. When spring comes and the water warms up, it migrates to the northern coast of America. After some time, numerous flocks are divided into sexually mature and immature. Those fish that are not yet ripe for spawning go to the southern shores. As the cat grows and matures, it turns into a real predator.
Social structure and reproduction
Puberty occurs at the age of 3.5 to 6.5 years. The first to open the breeding season are individuals belonging to the summer race. The vast majority of females that spawn are younger fish, whose age is not older than seven years. Only 16-18% — they are females over seven years old.
Representatives of the summer form begin to spawn at the end of summer, the beginning of autumn, precisely at the time when the water is as warm as possible, and its average temperature does not fall below 14 degrees. Representatives of the autumn form spawn in the fall with the onset of cold weather. The ideal place for spawning is not too deep zones, where the depth does not exceed two meters. The current in such places should not be strong, and pebbles, pebbles or gravel are best suited as a bottom surface.
After the most optimal place is found, the female prepares a place for spawning. First, with the help of powerful tail strokes, she clears the bottom surface in the place where she is going to spawn. After that, in the same way, she knocks out a hole in the bottom surface, the depth of which can reach half a meter. In each such hole, one female can lay about 6-7 thousand eggs. The total mass of caviar can reach one and a half to two kilograms. Then the males fertilize it, and the female carefully and reliably buries it in the ground.
Chum salmon is a fish that is highly prolific. One female can form up to three or four such clutches in different areas during one spawning period.
Interesting fact: After spawning and clutch formation, all fish die within about a month. This period is allotted by nature so that the fish can leave the spawning grounds and spread along the river in order to prevent an ecological catastrophe.
The incubation period is approximately 120-140 days. After this period of time, embryos appear from the eggs, which are placed in a special yolk sac. It performs the function of protection and allows the development of embryos without leaving the place of laying eggs. The first exit of grown fry occurs at the end – April, beginning of May. During this period, fry gather in groups and hide in coastal vegetation and stones. Due to the specific striped coloration, the fry manage to remain unnoticed by many predators.
Natural enemies of the ket
Chum salmon are perfectly adapted to living in the open sea. She has an optimal color, which allows her not only to wait for prey, merging with the bottom surface, or sea waters, but also to hide from enemies in this way. However, she still has enough natural enemies. At each stage of its development, it has a fairly large number of enemies. Other marine predators destroy chum salmon clutches by eating its eggs, prey on fry, as well as adults.
The main natural enemies of fry:
- Asian smelt;
Adult fish have enemies not only within sea waters. She has enough enemies that live on land. This is due to the fact that it can swim in shallow water and live in the coastal zone.
The enemies of adults include:
- seal ;
- Black-headed gull;
- beluga whale;
A special place among the enemies of fish is given to man. He hunts her on an industrial scale. Its caviar and red meat are of great value. Dishes prepared from this type of fish are considered a real delicacy, a culinary masterpiece, and are highly valued even among gourmets.
Ketu is caught using nets and seines. On the territory of the Russian Federation, chum salmon are caught in the middle reaches of rivers and near the mouth of the sea. Fish processing plants are built near large fish catch sites to avoid spoilage of meat and caviar.
Population and species status
To date, the number of fish in the world does not cause concern. This is facilitated by a high reproductive function. However, in Russia, the number of populations has significantly decreased over the past half century. This was facilitated by uncontrolled fishing and the growing number of poachers. To reduce fish catching in natural habitats, special artificial nurseries have been created in Sakhalin and Kamchatka, in which fish are bred for industrial purposes.
In Russia, the fishery supervision constantly patrols the regions of possible fish habitat and fights poachers. Also, chum salmon populations are protected by law from uncontrolled catching on an industrial scale. Private fishing, as well as industrial fishing, is allowed only after obtaining a permit and acquiring a special license.
The reduction in the number of chum salmon was facilitated by catching on an especially large scale by the Japanese about half a century ago. At that time, they scattered nets on the border with the USSR for 15,000 km. As a result of such actions, the chum salmon could not return to Sakhalin, Kamchatka and their usual spawning grounds. It was then that the number of fish was very sharply reduced. The population size that was before has not yet been restored.
Chum salmon is a very valuable representative of the salmon family. It is very much appreciated for its tasty and healthy meat, as well as incredibly tasty caviar.