These amazing fish
In the World ocean inhabits 180 thousand kinds of animals
According to scientists, man eating fish and other marine animals that uses only 0.02% of the primary production of seas and oceans.
Blood pressure in arthropods 5-10 mm Hg. article on the green frog – about 40, active fish – 65-75, birds and mammals – 120-180.
In rivers of Central Europe is inhabited on average 40-50 species of fish in the Danube – about 70 species, while the Amazon is more than 1 thousand kinds of all kinds of fish.
Many animals are very demanding in terms of ambient temperature. For example, Antarctic fish Trematomus lives at water temperatures of 1.9 O. temperature Fluctuations in their habitat at all times of the year do not exceed 0.1 A. Already at +60 the fish dies.
The first fish appeared in the Paleozoic era
The development of the Earth is divided into five time periods called eras. The first two eras, archeozoic and Proterozoic lasted 4 billion years, nearly 80% of the earth’s history. During arkasia was the formation of the Earth, any water and oxygen. About 3.5 billion years ago appeared the first tiny bacteria and algae. In the era of the Proterozoic, about 700 years ago in the sea were the first animals. It was a primitive invertebrate creatures, such as worms and jellyfish. The Paleozoic era began 590 million years ago and million years. Then the Land was covered with swamps. During the Paleozoic there were major plants, fish and amphibians. The Mesozoic era began 248 million years ago and 183 million years. At this time the Earth was inhabited by giant lizards, the dinosaurs. There were also the first mammals and birds. The Cenozoic era began 65 million years ago and is still ongoing. At this time, any plants and animals that surround us today.
In the Pacific ocean southwest of California far from the equator nearly to the Hawaiian Islands is a water desert. In this area, filtered 300 million liters of water, one would gain only a quart of marine organisms.
At the beginning of the Strait of Gibraltar, linking the Mediterranean sea with the Atlantic ocean, the seabed forms a barrier height of 320 m. in addition, there is a powerful undertow, directed towards the ocean. This explains that the deep ocean inhabitants are not able to overcome these obstacles and in the Mediterranean sea at a depth of 2 thousand meters found only 4 species of fish.
The biomass of plankton in the sea depends on depth. In the Atlantic ocean, for example, on the surface of water in 1 liter of water contains more than 100 thousand organisms. At a depth of 50 m in 1 l of water you can find is only about 40 thousand organisms at a depth of 100m – 5 thousand At a depth of 5 km in 1 liter water of about 20 found in living organisms.