Leukocyte formula features of bleak (Alburnus alburnus Linnaeus,1758) from different type reservoirs (for an example of Saratov reservoir and smaii rivers of Republic of Udmurtiya)

In 2011, the leukocyte counts in bleak of Saratov reservoir and two small rivers in the republic of Udmurtiya were investigated. These reservoirs are characterized by different hydrological regime and degree of anthropogenic impact. For the first time comparative analysis of occurrence of individuals with different leukocytes level in the blood stream is made, significant differences for this indicator in reservoirs with different levels of pollution are set. The calculation of the index of leukocytes shift (ISL) is made. It is found that its value in the most of the bleak individuals of Saratov reservoir does not meet the conventional standard which is a sign of increased anthropogenic stress.