The effects of clove oil on adult males and females of rainbow trouts (Oncorhynchus mykiss) and brown trouts (Salmo trutta fario)

Anesthetics are used for performing basic procedures such as weighing, tagging, experimental work, harvesting, spawning procedures and during transportation to prevent physical injury and reduce metabolism in aquaculture. Using of natural plant materials such as clove oil (eugenol) for sedation of fish becomes more important in aquaculture industry. In this experiment, different concentrations of clove oil (20, 30 and 40 ppm) were applied on broodstock of brown trout (Salmo trutta fario) and rainbow trout (Oncorhynchus mykiss) of different genders. Times to induction and recovery from anesthesia were measured. No fish died during trials. Induction times of anesthesia varied with clove oil concentrations, decreasing with the increase of clove oil concentrations. On the other hand, recovery times increased with decreasing of clove oil concentrations only on male trouts. The induction times for fish exposed to 20 ppm clove oil were generally longer compared to 30 and 40 ppm (p<0.05). Dose of 30 ppm clove oil produced rapid anesthesia with shorter recovery for females in both of species. On the other hand, the shorter recovery times were recorded for males in both species at 20 ppm. According to our results, recovery times were more gender-dependent for adult rainbow and brown trouts (p<0.05). Recovery times were shorter in adult females than males, especially for 30 and 40 ppm clove oil, while male brown trouts were induced longest times in these dosages (p