Heavy metals in organs and tissues of the paddlefish Polyodon spathula (Walbaum) in fish ponds of the Forest-Steppe and Forest area of Ukraine

Purpose. To investigate the peculiarities of heavy metal (Fe, Zn, Mn, Cu, Ni, Co, Pb, Cd) accumulation in organs and tissues of the North American paddlefish Polyodon spathula (Walbaum) introduced into inland water bodies of Ukraine. Methodology. The objects of the study were age-4-7 paddlefish reared in ponds of the forest-steppe and forest area of Ukraine. Age-3 carp as well as hybrids between the bighead and silver carps reared in polyculture with experimental groups of the paddlefish were used for comparative evaluation of the peculiarities of heavy metal accumulation in fish muscular tissues. The studies of the heavy metal content in pond water, fish organs and tissues were performed with the use of generally accepted toxicological methods. The quantitative contents of heavy metals were determined with the aid of the atomic-absorption spectrophotometer C-115-M1. Findings. The toxicological state of the experimental ponds was characterized by elevated values of the contents of Mn (by 8.5-8.9 times), Cu (by 2.1-3.9 times) and Pb (by 1.5-1.80 in water. The concentration of other heavy metals in water did not exceed the allowed values. Similar patterns were found regarding the heavy metal distribution and accumulation in paddlefish organs and tissues as for carps. No maximum allowable concentrations of heavy metals were detected in the muscular tissues of the paddlefish. Among all studied fish reared in polyculture, the paddlefish had the lowest content of Cu, Co, Pb and Cd in muscles. The mean heavy metal contents in paddlefish muscles in the studied ponds of forest-steppe and forest area were: Fe (4.64-29.60), Zn (1.20-5.54), Mn (0.10-0.23), Cu (0.09-0.44), Ni (0.28-2.15), Co (0.10-0.13), Pb (0.63-0.94), Cd (0.031-0.037). Originality. The peculiarities of the distribution and accumulation of heavy metals in organ and tissues of the North American paddlefish reared in the conditions of pond farms of Ukraine have been studied for the first time. Practical value. The study results is an essential component of the material for the creation of a database for the determination of product quality of domestic sturgeon culture, in particular regarding the peculiarities of heavy metal accumulation in fish.