Aquarium guide
Aquarium guide     

  
 
FRESHWATER FISH
 

FRESHWATER FISH

These inhabit various biotopes in tropical and equatorial regions. Basically they may be divided into two groups. The first comprises those for which soft, acidic conditions are essential. Some require a very low level of hardness, with a typical pH of around 6. The second group prefers hard, alkaline conditions. For some species the level of hardness must be extremely high, with a pH of up to 8. A few species can survive in brackish water. There are some fish which are not dependent on water quality. These are consequently ideal for the beginner, who can, in principle, fill the aquarium from the household supply. Though there are over 10,000 species native to inland waters, only a few hundred need concern the aquarist.


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СУДОПЛАТОВ Павел Анатольевич (1907-96) , разведчик. С 1921 по 1953 в органах государственной безопасности СССР. В 1940 руководил операцией по ликвидации Л. Д. Троцкого. В 1943-46 осуществлял координацию работы советской разведывательной сети в США, занимавшейся добыванием информации по созданию атомной бомбы. В 1953 обвинен в пособничестве Л. П. Берии и приговорен к 15 годам заключения. В 1992 реабилитирован. Автор мемуаров "Разведка и Кремль"(1996).