Some aspects of the pathological parameters of the biochemical indicators of the blood of the Caspian roach Rutilus rutilus caspicus and bream Abramis brama in the modern environment conditions of the Volga-Caspian basin

Caspian roach (Rutilus rutilus caspicus) and bream (Abramis brama) are the objects of commercial in the Volga-Caspian basin. Was studied the presence of roach and bream individuals with pathological changes in some blood parameters. The materials were collected in 2008–2014 at the fishing grounds at the lower Volga reaches and Northern Caspian. Specimens of roach and bream with pathological changes of the quantitative characteristics of the studied blood parameters (hemoglobin, β-lipoproteins, total serum protein, cholesterol and total lipids) were revealed in various study periods, hence at different stages of maturity of fish gonads. The ratio of pathological versus healthy individuals of Caspian roach and bream has varied annually which relates directly to the power of the negative influence of their habitat environmental conditions. The change in the pattern of spring flood, the deterioration of the foraging conditions at the sea, the pollution of the Volga River and the Caspian Sea are the key factors determining above phenomena. In 2010–2014 pre-spawning periods the greatest number of roach and bream individuals with deviations from the norm was revealed. These deviations concern quantitative characteristics of the content of β-lipoproteins and cholesterol. In the spring 2014 the vast majority of roach (96%) exhibited pathologically low level of hemoglobin in the blood, i. e. anemia. In 2008–2013 pre-wintering period prevailing number of roach and bream individuals with quantitative characteristics of the content of β-lipoproteins and cholesterol deviated from the norm was recorded. In 2010–2011 in bream and in 2009–2010 in roach from 23% to 40% individuals with pathologically low level of blood hemoglobin were revealed