water area of the planet inhabited by about 20 000 different species of fish.About one tenth of them relates to fishing.In addition to food, commercial fish provide us medicines, industrial raw materials, technical fats, fertilizers, pet food.Commercial fish are divided into freshwater, anadromous and marine.
freshwater fish, which share in the global catch is about 11%, lives in rivers, lakes and ponds.Greatest commercial value are catfish, carp and perch fish.
biggest fish that live in the rivers - this Amur Kaluga (representative of the sturgeon family), whose weight can reach 1000 kg and a length of 5 m, Chinese psefurus (length up to 7 m), European catfish that grows up to 5 m in length, andover 300 kg in weight, South American arapaima (200 kg, greater than 4.5 m in length).But the giants are rare.Most freshwater fish found in local waters, has a medium size.
freshwater fish for commercial purposes is partially diluted in a special artificial ponds - for example, trout, carp, tilapia, carp, carp.From living in rivers and lakes are most important to catch pike, catfish, carp, crucian carp, bream, perch, roach.
in natural waters freshwater fish lives mainly off the coast, where a lot of food and a comfortable place to spawn.In the summer in the shallow waters you can always see shoals of fry.In the immediate area live fish, not too demanding on the quality of water, t. E. Its purity and oxygen content.This pike, carp, tench, roach.A little further live perch, bream, ide.Catfish, perch and salmon choose the most distant and clean place.
These kinds of river fish like trout, loach, spined loach are found in streams.The small lakes are found mainly pike, roach, eel and ruffe.Large lakes in the number of species are not inferior to marine waters.The number of species of fish there more than a few dozen.
oxygen content in the water - a crucial factor in the diversity of the composition of its inhabitants.The poorly oxygenated waters are found, only the most hardy fish, as in the heat of summer and very cold in many of their species are dying from suffocation.Line and carp can exist in oxygen-poor small ponds that freeze through the winter.Ruffs tolerate oxygen starvation, but require clean running water.
most demanding of high oxygen content are salmon, walleye, sturgeon.
Freshwater fish also react to temperature fluctuations.Some of its species are unable to exist at temperatures below certain.So, for fish of the carp family, the figure is 10 ° C.Any fish can not tolerate high temperatures (whitefish, burbot, char).In hot weather they hide under rocks and get out only with the onset of cold.Other fish may well exist in cold water and even survive through freezing waters.In the cold winter in certain types of fish can go into anabiotic state.
Freshwater fish is also sensitive to sunlight.Here, too, there are fans lit and dark waters.Lamprey prefers darkness, and roaches, for example, going to the sun, well-lit areas.Fry the salmon from the glare get into the rocks.
Experienced anglers can determine what kind of fish is flown in a water depth not only in appearance, but even the characteristic surge, as each of them moves in its own way.
Fishing in our country - the national favorite form of recreation, which includes elements of the competition, sports passion, communication, adrenaline, fresh air and the practical side of things as a legitimate catch.Nowadays, there is a practice of breeding fish in special ponds with the subsequent sale of licenses for visiting and catching fish in them.
