N. Naydenova Department of Animal husbandry – Ruminants and Dairy farming, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria (Manuscript received 5 June 2021; accepted for publication 30 August 2021) Abstract. The predominant influence on the structural-mechanical

M. Stancheva, A. Merdzhanova Abstract. The aim of the present study was to determinate the fatty acid composition of two commercially important freshwater fish species – rainbow trout (Oncorhynchus mykiss) and carp (Cyprinus carpio L.) and one Black Sea fish – grey mullet (Mugil