Kofonov K. Morphophysiological status of juvenile cyprinids under the influence of increased content of biogenic compounds in water

The paper considers the main regularities of changes in juvenile cyprinids' viability, morpho-physiological and biochemical state under the influence of increased concentrations of ammonium nitrogen and phosphorus phosphates under experimental and natural conditions. Our team identified the most significant and indicative morphological, physiological, and biochemical indicators used in modern ichthyological and biochemical studies. One of the results of our teamwork was lethal concentrations of ammonium nitrogen and phosphorus phosphates for cyprinid fish species. However, their viability at elevated concentrations of these compounds differed significantly. Also, we discovered species-specific physiological, biochemical and adaptive reactions in response to harmful environmental factors in juvenile carp, crucian carp, common rudd and roach. The investigation conducted that young cyprinid species fish used all three energy substrates in the process of adaptation to excessive concentrations of ammonium nitrogen and phosphorus phosphates. Initially, glycogen is utilized, later or simultaneously with its lipids. Last, of all, juveniles of cyprinid fishes used proteins for the energy supply of adaptive responses to pollution. Centred on the findings, we could note that some biochemical indicators, such as the content of hormones and the activity of LDH and ALP, are potentially helpful for biomonitoring and indicate different water bodies' ecological states. Also, the work, in turn, expands and supplements the existing information on the adaptive reactions of the organism of cyprinids to changes in the ecological conditions of the habitat at the morphological, hormonal, enzymatic and biochemical levels.