الفهرس 
Cover Page Title in EnglishOnly 14 pages are availabe for public view
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Abstract
One of the most serious problem encountered in fish farming is the difficulty to differentiate between male and females in most of fresh water fish, during the breeding season and sometimes at the beginning of the season, so this study amid to found simple method to know the sex of fish by the measuring a specific female protein, which is the precursor of egg yolk (vitellogenin), this protein is formed in the liver of female fish and then transported to the ovary under effect of estrogen. This protein is not present in the male or juvenile fish, but it can be present in these fish, in special cases, as presence of these fish in environment containing chemical potetiating the formation of this protein (xenobiotic factors).
The measuring of such protein in serum of male fish indicate the presence of pollutant chemicals which resemble estrogen in its action. For this aim we established a method to measure this protein.
First experiment:
Fifteen mature female common carp fish were used with average weight 3 kg in May 2002
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