We all know that water is life. Without water can’t live no living creature. And the first life originated in water. Fish one of the many live organisms living in the aquatic environment. They live in the oceans and seas, rivers and lakes. You can see them in the pond and the stream, in the waters of caves and even in puddles. In nature, there are over 25,000 species of fish, and they are divided into two classes: Bony fish (more than 23 000 species); Cartilaginous fishes (9000 species).
To the class of cartilaginous fish include sharks, rays and chimeras. To the class of bony fish include salmon. okuneobraznyh. preobrazenie. clupeiformes. Cypriniformes, catfishes, wildcookie, flatfish, coloscopie.
Fish are cold blooded vertebrates. their streamlined body covered with scales. They breathe with gills, and with the help of fins and tail to swim. Water entering the body through the mouth, passes through the gills, and spilling over her holes. Oxygen enters the bloodstream Continue reading
In the seas and oceans of our planet are populated with over 21000 species of fish. About ten percent of them belong to the industrial types. Breeding allows you to obtain not only the fish as a commodity, it is the raw material for the production of medicines, fertilizers, pet food. Industrial fish are divided into freshwater and marine.
Freshwater species are fish that inhabit the ponds, lakes, rivers. The main industrial freshwater fish species are catfish, carp, perch. To artificial breeding of well adapted to black bass, trout, carp, Amur, silver carp. Such kinds of fish as pike, perch, catfish, carp, crucian carp, bream, take the first place in terms of industrial production in our country.
Particularly valuable of freshwater species of fish are:
sturgeon and stellate sturgeon, Beluga, sturgeon, this species of fish has a very tasty and fatty meat, and from them collect valuable Beluga caviar;
salmon – humpback salmon, chum salmon, Steelhead, these fish species are given, in addition to high demand of red caviar, delicious meat. Continue reading
Sharks are found in open and coastal ocean waters. These mysterious creatures appeared on Earth 400 million barrels. years ago. Belong to cartilaginous fish. as their skeleton consists of cartilage. Cartilage is durable, and unlike the bones of fish, more flexible and light. They have no swim bladder. Afloat fish holds, thanks to its large but lightweight the liver. Her need to constantly move in order not to drown.
She swims, arching his whole body from side to side. Almost all of them when hunting using the electric field. Sharks capture him with the help of numerous electrical sensors that are on her face.
Many of them, it is not strange, they eat plankton. Plankton is a conglomeration of various microscopic and small organisms. Mainly unicellular plankton contains algae, which absorb solar energy, thereby transforming inorganic substances into organic food. Continue reading