The flora and fauna of the Black sea is quite diverse, although in recent years, in connection with the anthropogenic activity and has undergone significant changes in its composition and strength. For the most part, the denizens are a species brought from the Mediterranean, here there are even a few relict species. Living organisms can be found at depths up to 150 metres, before the beginning of the hydrogen sulphide layer, which also determines the relative poverty of the animal world, compared to the Mediterranean sea.
Algae of the Black sea includes 270 species of multicellular benthic algae and 600 species of phytoplankton. The most common types are villaflora, kladofora, cistozira, Ulva, Zostera. In the summer the most active development escobilla and ceratium. Common diatoms.
The fauna is even more diverse, it includes more than 2500 species of animals, most of which were unicellular and crustaceans – about 500 species. In second place – shellfish, about 200 species, and only fish 160 species. The rest of the mass consists of numerous species of invertebrate animals. Continue reading
SHARK . superorder of cartilaginous fish. Includes 8 units and approx. 350 species distributed in all oceans. The most diverse and numerous sharks in the tropics, but occur also in temperate and even in cold waters. Live in the water column and near the bottom, at great depths and in the coastal shallows. Ascend rivers for hundreds of kilometers (eg. the Amazon) that inhabit lake Nicaragua and some others. In Russian waters approx. 10 species, including katrenova shark (spiny dogfish), polar shark, mackerel sharks and hammerhead sharks .
The body of sharks is well adapted to fast and maneuverable swimming. It has an elongated, torpedo-like shape and ends in a large tail fin. DL. body from 15-20 cm (some kind of old-fashioned recourses and weasel sharks) to 20 m (with a weight of 12-14 tons) of whale shark . Since the density of the body of sharks is greater than the density of water, they must constantly move, not to go to the bottom. Best swimmers – Mako speeds up to 60 km/h; when the throw to the prey speed increases. Jaws are armed with a large number of sharp teeth, easily cut through any sacrifice. Continue reading