There are freshwater and marine fish. How do they live in the water? They breathe the oxygen dissolved in it.
Every time you open your mouth, the fish absorbs the water. The oxygen dissolved in the water absorbed inside the body of the fish straight into the bloodstream. The wastewater is then discharged through the gills, usually located on the sides of the fish’s body, behind the head.
Mudskipper is a fish with very interesting habits. There are jumpers in the Eastern Atlantic, Indian and West Pacific ocean. It lives most often in the quiet bays near river mouths. This remarkable fish that at low tide remains on land and, using fins and a special breast suction Cup, can climb trees to a height of more human growth: here it preys on insects.
In fresh water rivers and lakes inhabited by many species of fish. Freshwater fish feed on different food. Some eat algae, other aquatic insects and mollusks. Some fish eat other fish; they are real predators.
In certain types of freshwater fish are found only in one river or lake, others dwell in many places. Sometimes fish eggs is transferred to a new place, glued to the feet of waterfowl, and sometimes fish can move people. Some fish themselves swim in other rivers. When the salmon is four years old, he leaves the river and goes to sea.Having lived in the sea and two more years, he returns to lay her eggs. Many salmon return to their native river, but some moved to other rivers. Continue reading
There are some foods that are simultaneously rich in iron, phosphorus, zinc, magnesium, calcium, selenium, vitamins A, E, D, and amino acids that are necessary for the normal functioning of the cardiovascular system, thyroid gland and stomach. But in fish, all these elements abound. Therefore it is very importance of fish in human nutrition. In addition, this product small fat content (30%), it is perfectly assimilated by the human stomach digests the protein contained in fish, only 1.5-2 hours compared to 5 hours it takes to digest, say, beef.
The importance of fish in nutrition
People suffering from excess weight, just perfect river fish, which contains 2.5 grams of fat per 100 grams of weight. But suffering from diabetes can have it without any restrictions, because the number of carbohydrates it is small – only 0.1%.
Fish, competing in this regard with the chicken, is an excellent source of high quality protein which contains all necessary for normal functioning of amino acids. It also differs from meat protein by the presence of methionine.
Due to the fact that the collagen that makes up connective tissue, has the property of rapid transition in a soluble form, fish is easy to cook, and its tissues become loose, blagodaram provides maximum and rapid absorption of all nutrients. The most rich in protein fish include salmon, trout, and salmon, Beluga, easier to say that all representatives of groups of sturgeon and salmon. Great importance in human nutrition fish is also underpinned by a very high nutritional value due to high concentration of fatty acids. It refers to oily marine fish – salmon, mackerel, herring, trout, salmon and other things. Continue reading
Pond fish farming is a type of economic activity. which uses high-yielding species for cultivation in specially equipped natural and artificial water bodies for the purpose of receiving all kinds of fish products.
Pond aquaculture also includes the complex of measures on construction of fish ponds, swimming pools and other bodies of water: the digging of ditches, dams and levees, water supply and water discharge facilities, rybolovleva, etc.
This includes scientifically developed techniques for breeding, artificial reproduction, feeding and the optimum conditions of the fish to ensure a productive outcome.
The content of fish in pond fisheries.
In the same pond can be kept as a single species of fish, and several species simultaneously. Remember to take into account the characteristics of each species and their mutual compatibility. Some species of fish require cold flowing water saturated with oxygen, another — warm standing water with lots of organics and small amount of oxygen. Some species of fish to mohalalitoe only in freshwater, some in saltwater, and there are those that can live in that.
To a cold-water fish include trout. burbot, pike, salmon, Arctic Cisco, grayling and others.
The technology of fish culture and fisheries include not only the maintenance of a temperature mode. This includes providing fish with oxygen, water disinfection, filtration of harmful components and toxins, prevention of the disease. the fertilizer ponds. the destruction of noxious vegetation and various wastes, maintaining appropriate pH and other measures. Continue reading