The most dangerous and poisonous animals of Russia
The most dangerous and poisonous animals of Russia live near the person. More than half the population of the Russian Federation living on the territory, inhabited by various the most…

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The structure of the pharynx, the feeding of fish.
The structure of the pharynx is also closely linked to feeding habits of fish. As indicated, the number and structure of Gill rakers may be very different — from a…

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Black sea (Pont Evxs)

The greatest length of the Black sea from North to South — 580 km and a maximum depth of 2210 m, the average — 1240 m. the salinity of the water is approximately 18 ppm. The depth increases pretty quickly. Over a sloping beach near Evpatoria, Feodosia. On the South coast, in mountain areas, the depth increases more rapidly: a few meters from the shore you have to swim (or, in the alternative, to swim along the shore). Be careful, even at a short distance from the shore can be strong currents to deal with which is not prepared person is quite difficult. But mostly this does not apply to places of mass bathing (if not to swim too far). Waters of the Black sea, as a rule, not susceptible to freezing. The average sea temperature in winter ranges from +6 to +8 degrees, in summer — from +22 to +24 degrees (can warm up to 26 degrees in a particularly hot summer). However, it is worth noting that the Black sea could throw a “surprise”: one day deep cold currents cool the coastal waters up to 12 degrees, even Continue reading

To settle on the aquarium. Marine fish.

The first two weeks in the system was the rapid development of heterotrophic bacteria feeding on organic waste products of marine fishes . The result is what appear in water ammonia and ammonium, whose concentration quickly reaches a maximum. It is very unpleasant, but a natural phenomenon is called and can be detrimental to aquatic life. That’s why, to avoid the risk, tender fish species inhabit the aquarium only after a month or two after system startup of the biofilter. As nutrients in the form of ammonium in the substrate begin to develop nitrifying bacteria converts it into significantly less toxic nitrites.

At the third or fourth week, the concentration of nitrites reaches a maximum, which also, despite the decrease in ammonium concentration, it is dangerous to aquarium inhabitants. In turn, the bacteria of another species, consuming nitrites, gradually reduce their concentration, and biofilter begins to work normally. It must comply with one prerequisite – oxygen mode: the oxygen content of the water should be close to saturation. This is achieved by use of active aeration. Continue reading