Optical methods for assessing the effect of DON-1R on the histological structure of fish liver

Abstract

With the help of optical methods of fish functional state diagnostics the possibility of using DON-1R, a drug that contains γ–crotonolactone, in recirculating aquaculture system was proven. It was stated that adding DON-1R to granulated feed while feeding sturgeon fish stimulates the raise in mass accumulating velocity. Moreover, microscopical analysis of histological cuts and detailed analysis of their photomicrographs with the use of various approaches in contrasting images showed that feeding with feed with DON-1R is accompanied with reactive changes to the liver. In particular, fish that received the tested drug had the inequable liver cytoarchitectonics, chaotic hepatocytes placement, radial character of liver channels and undefined sinusoids. Hepatocytes of experimental fish had large hyperchromatic nuclei with 4,5 μm diameter with multiple tiny defined nucleoli. Control fish’s nuclei were 1,5 times smaller, had even coloring and 1-2 nucleoli. Moreover, fish from experimental group had signs of partial acidophilic coagulation, such as occurrence of homogenous pink lumps in cytoplasm (Mallory bodies). It is worth noting that the application of DON-1R does not lead to deep destructive changes in liver structure, such as necrosis of fibrosis. Taking all of the above into consideration, DON-1R is the most effective for growth stimulation if applied for a short period of time for commercial growing. Optimal period of use is 20 days.