The Mediterranean sea is a part of the ancient Tethys ocean, with an area of 2.5 million square kilometers; the volume of water in the sea is about 3.8 million cubic km, and average depth is more than 1.5 thousand meters. In such considerable dimensions of the Mediterranean sea, its fauna is characterized by significant species diversity, but populations of animals of each species is relatively small. This is mainly due to a small number of plankton in marine waters.
In the Mediterranean there are 593 species of fish, of them in Israeli waters, home to 291 species (mackerel, herring, mullet, tuna, dolphinfish, palamidi, horse mackerel and many others). The Mediterranean coast of Israel encountered 4 species of flying fish. Many fish in the Mediterranean are of commercial importance. Continue reading
The fauna of the Black sea is markedly poorer than the Mediterranean sea. In the Black sea is home to 2.5 million species of animals (including 500 single-celled species, 160 species of vertebrates — fish, mammals, 500 species of crustaceans, 200 species of mollusks, and the rest — invertebrates of different species). for comparison, in the Mediterranean — about 9 thousand species.
Among the main reasons for the relative poverty of fauna of the Black sea: a wide range of water salinities, moderately cold water, the presence of hydrogen sulfide at high depths. In this regard, the Black sea is suitable for habitation fairly undemanding species, at all stages of development which do not require great depths.
At the bottom of the Black sea inhabited by mussels, oysters, pecten, and the mollusc-predator Rapana included with vehicles from the Far East. In the crevices of the coastal cliffs and among the rocks is home to many crabs, there are shrimps, there are various kinds of jellyfish (the most common are Aurelia and kornerot). anemones, sponges. Continue reading