Measurement of the lethal concentration of thyme essential oils in rainbow trout (Onchorhynchus mykiss)

The importance of the use of medicinal plants against infectious and non-infectious diseases is completely obvious. The replacement of synthetic drugs due to their multiple properties in the prevention and treatment of many diseases, particularly in the aquaculture industry seems to be very important. This study was performed with the aim of assessing the acute toxicity (LC_50-96) of thyme essential oil on rainbow trout. To study the effect of the essential oils, 80 premature rainbow trout with an average weight of 10±0.5 in 9-liter tanks were exposed to different concentrations of essential oils of thyme and daily losses based on OECD protocol were calculated during 96 hours. All the physical and chemical factors such as water temperature, dissolved oxygen, pH, nitrite, nitrate, ammonium levels, electrical conductivity and water hardness were measured in different treatments. The acute toxicity of the essential oil of thyme was calculated using probit analysis and a concentration of 4.4 ppm was determined