ASSESSMENT OF THE COMBINED EFFECT OF HEAVY METALS AND SURFACTANTS ON CARP FISH ORGANISMS

Pollution of aquatic ecosystems is one of the current environmental problems that negatively affects aquatic organisms, in particular cyprinid fish. Heavy metals and surfactants are the main anthropogenic toxicants that can cause significant morphological and biochemical changes in the body of fish. Research into their impact is important for assessing the state of water resources and developing measures to reduce environmental risks. Purpose of the work: to assess the impact of heavy metal ions (Zn²⁺, Cd²⁺) and sodium lauryl sulfate on the morphological and biochemical indicators of the carp body. The object of the study is biochemical and morphological transformations in the carp body. The subject of the study is changes in the content of glucose, proteins, lipids and moisture in carp tissues under the influence of toxic substances. Methodology. The study was conducted on two-year-old carp of the scaly and mirror morphotypes (Cyprinus carpio L.) weighing 250–350 g. Fish were kept in 200 dm³ aquariums with settled tap water, in which a stable hydrochemical regime was maintained. Toxic load was created by introducing appropriate concentrations of Zn²⁺, Cd²⁺ and sodium lauryl sulfate. Morphological changes (damage to the skin, fins, gills) and biochemical parameters (content of glucose, proteins, lipids and moisture in tissues) were analyzed. The results obtained were processed by statistical methods. Scientific novelty. For the first time, the combined effect of heavy metals and surfactants on the morphological and biochemical parameters of the carp organism was studied, which allows using ichthyological parameters as bioindicators of aquatic environment pollution. Conclusions. During the experiment, changes in the appearance of the fish were observed, in particular damage to the fins and skin and scales, increased mucus secretion in carp that were in an aquarium with sodium lauryl sulfate for 14 days. When toxicants of various origins act on the fish body, the glucose content is more sensitive than the total protein content. These indicators can be recommended for monitoring water bodies using fish of the cyprinid family. Under the influence of toxic environmental conditions, a decrease in the lipid content was observed in both white muscles and liver tissues, with the exception of the simultaneous exposure to sodium lauryl sulfate and ions. An increase in the amount of lipids in the liver can lead to exhaustion of the body and indicate tissue degeneration. When studying the effect of toxic substances on the moisture content in various carp tissues, no significant changes were observed. The presence of a multi-stage cell defense system, which has developed during phylogenetic development, determines the complexity of the cause-and-effect relationships between biochemical processes and their focus, primarily, on maintaining the optimal metabolic balance of the cell and the organism as a whole, which is expressed in changes in biochemical indicators.