Features of the morphofunctional and physiological state of sturgeon fish with nephrocalcinosis in cage aquaculture conditions

When growing sturgeon fish in cages, which are especially valuable nowadays, great attention should be paid to their health. Along with other pathological manifestations of various natures, a disease such as kidney nephrocalcinosis can pose a potential danger to these aquaculture objects. This pathology was recorded in juvenile sterlet (age – 0+ years), in immature individuals of Russian sturgeon (age – 2 years), in which clinical and pathological examinations were carried out, including pieces of kidneys were selected for histological analysis, blood samples for carrying out hematological and biochemical studies. The appearance of nephrocalcinates in the kidneys of sturgeon fish was confirmed using histological methods: corresponding pathological transformations were found on micropreparations of the kidneys of Russian sturgeon and sterlet. Morphophysiological changes in the condition of the kidneys of the studied sturgeon fish can be assessed as moderate and minor, not life-threatening. Thus, 60% of the examined individuals of Russian sturgeon did not have any detected pathohistological changes in the organ; among sterlet there were 80% of such individuals. When analyzing hematological and biochemical blood parameters, deviations of some indicators were found. Thus, the sterlet had a low level of hemoglobin, all fish had an insufficient number of red blood cells in the blood; in Russian sturgeon, a high level of pathologically altered erythrocytes was determined, the amount of serum protein was increased, deviations were found in the ratio of its fractions, high levels of uric acid, low levels of triglycerides, β-lipoproteins, ALT and AST activity in the blood. Indirectly, these changes in the physiological state of sturgeon fish with nephrocalcinosis indicate that this disease most likely arose as a result of the influence of a complex of factors on the fish, among which the main ones may be disturbances in the hydrochemical regime and the balance of feeding.