How do salmon fish live?
Salmonids are the only family in the world.suborder salmoniformes. Among them there are both freshwater and transitional species. Of these, the most common are: salmon, keta, pink salmon, coho salmon, sockeye salmon, chinook salmon, whitefish, trout, grayling, omul, char, taimen and lenok. Most of these fish are called simply collective names: trout and salmon.
Salmonids appeared about 145 millionyears ago. The structure and form they are very similar to herring-shaped, and in some classifications they even unite. But salmon can easily be distinguished by a well-traced lateral line on the trunk. The division of the family into modern species occurred 62-25 million years ago.
Distinctive features
Fish family salmon can have a body length of several centimeters (eg, whitefish) up to two meters, and their weight can reach seventy kilograms (taimen, salmon, chinook).
The absolute record holder in terms of size istaimen. This fish family salmon can live more than fifty years, have a weight of one hundred kilograms, a length of more than two and a half meters. The body is long and narrow, covered with round scales.
All salmon fish have one dorsal fin and one fatty fish behind it.
Reproduction
Life expectancy in some species can reach fifteen years.
They can only breed in fresh water. At the same time some species permanently live in the lakes, but most of them rise to spawn from salt water to fresh water. Most often they return to the same place where they were born. It is still unknown how exactly they find their native river. Perhaps, according to the heavenly stars and bright constellations, or to the taste of water and the subtlest features of its composition.
During spawning salmon change their shape and color (put on a "wedding attire").
Spawning
As already mentioned, the reproduction of salmonoccurs only in fresh water - in streams, rivers or lakes. This is due to the fact that their ancestors were freshwater, and only some of their descendants evolved into migratory fish - these are Atlantic and Pacific salmon.
Before this process, salmon fish significantlychange both externally and internally. Coloring from silvery becomes red-black, males may sometimes show a hump, teeth become larger. But almost all internal organs degrade, meat becomes less elastic and, consequently, less valuable.
Place of residence
Most salmon live in the Northhemisphere. The most common are in North Asia, Europe, North America, and also in the mountains of North Africa. In the Southern Hemisphere, this family is absent in the natural habitat, but in some places they are artificially acclimatized and bred.
Fishing
Their meat has a characteristic taste and is very richuseful substances, therefore all kinds of salmon are an object of fishing. They yield a catch that is about three percent of all the marine fish produced.
