MN and ZN content in eggs and musculature of rainbow trout ( Oncorhynchus Mykiss W. ) treated with fungicide mancozeb and pigment astaxanthin

The present study aims to determine the levels of the heavy metals manganese (Mn) and zinc (Zn) contained in the fungicide Mancozeb in the eggs and musculature of the rainbow trout (Oncorhynchus mykiss W.) which have grown in an environment, containing a permissible amount of Mancozeb and fed with or without the carotenoid pigment astaxanthin. The study follows the feeding, then the analysis of the level of Mn and Zn in the eggs and musculature of the rainbow trout, treated with and without the pigment astaxanthin and the fungicide Mancozeb. The determination of Mn and Zn concentrations is performed using a modern method for measuring macro- and microelements with an atomic absorption spectrometer, which is characterized by high selectivity, swiftness and sensitivity. Experimental data show accumulation of Mn and Zn, contained in the fungicide Mancozeb even when its concentration in the habitat does not exceed the maximum permissible levels in the normative documents. As a result, the analysis of the eggs and musculature shows the same trend regarding the accumulation of Mn and Zn. In non-fertilized, as well as in fertilized rainbow trout eggs and musculature, the experimental data show a slight increase of Mn and Zn in the presence of only astaxanthin in the added feed and a significant decrease in these metals in the presence of both astaxanthin and Mancozeb. The supplementation of astaxanthin in the diet can significantly reduce the rate of heavy metals accumulation in fish tissues and eggs, but high concentrations of these pollutants in the aquatic environment over a longer period of time would certainly result in metabolic disturbances in the fish body and reduction of their eggs’ hatchability.