Though marine fishes drink a lot of water, their freshwater relatives don’t drink nearly anything. The root of this difference lies in the needs of fish to maintain a normal balance of salt and water in the body.
The water in the ocean three times saltier than its own liquid environment living in the ocean fish. As a result of a natural process known as osmosis, water body sea fish rushes out through the skin and gills. To compensate the lost liquid, saltwater fish forced to consume large quantities of sea water.
The concentration of salt in the body of freshwater fish exceeds its content in the surrounding water, which is why freshwater fish do not drink, like a sea, and constantly absorb water through the skin. The excess liquid they secrete in copious urination. Continue reading
The content of the fish in a saltwater aquarium can be very challenging. Maintenance of the necessary salinity of the water and a sufficiently high oxygen level in it even in a well – equipped aquarium is not easy. Most marine fish bred in aquariums, is habitat, so these fish cannot tolerate fluctuations. Reef the oxygen level is always high and a lot of light, because the corals grow only in shallow and clean water.
Sea water is very corrosive, so the aquarium must be made entirely of glass or plastic, without metal parts. Although marine fish are less inclined to jump out of the vessel compared to freshwater, the aquarium must be carefully closed to avoid contamination. It will also help to control evaporation: when water evaporates, salinity increases, so the vessel should be topped up with distilled water. Continue reading
Among the fish, horror at the man, the most terrible is the white shark. But no less chilling stories to tell about the little fish-the piranha. In many legends she is able to strip a large animal in just half an hour. Only the water gets a drop of blood, piranha transforms into a crazed demon who hits on anything that he comes across.
Here it is — the famous and legendary piranha. A small fish, only some 20 cm, with purple (female) or blue-black (male) color. Can also be olive-silver or bright red. Nice fish? Believe me, it’s no longer be the case. Piranha known reputation of bloodthirsty fish. Just look at her strong jaw with many sharp, pyramidal teeth.
The name itself is fraught with danger. The word “piranha” is borrowed from South American Indians and means “sharp-toothed demon.” Indeed, the teeth they terrible. Jaw muscles are so developed that the piranha can to shave off the smallest piece. She does not tear the prey, and cut it in pieces, like a surgeon with a scalpel. The teeth are very sharp, no thick skin no protection. Adult piranha can bite a stick or a human finger. Piranha can even bite through steel. Piranhas are especially dangerous during the spawning season, when fish pair first, and later one male, guarding a clutch of eggs. Continue reading