Determination of lethal concentration (LC96h) of hydroalcoholic extract of garlic (Allium sativum L.) and its effects on gill tissue of Persian sturgeon (Acipenser persicus) fingerlings

Today, the importance of using herbal drugs for campaigning against infectious and non infectious diseases is completely obvious and the need to replace them with chemical ones, particularly in the aquaculture industry, seems essential.This study was carried out to determine thelethal concentration (LC96h) of hydroalcoholic extract of garlic (Allium sativum L.) in Persian sturgeon (Acipenser persicus) fingerlings. Fingerlings were 3.22±0.51g in weight. In order to study the effects of these extracts, 240 fingerlings were selected in seven treatments and one control group with three replications for each treatment. During the experiment, all water physicochemical parameters including the temperature, dissolved oxygen, pH, nitrite, nitrate, ammonium, electric conductivity and water hardness were measured. This experiment was carried out according to O.E.C.D method within 96h. In this regard, the linear regression equation was drawn using probit analysis, and then different values of lethal concentrations were estimated. In this survey, according to probit analysis, the LC10, LC50 and LC90 of hydroalcoholic extract of Allium sativum were recorded to be 909.91, 1279.97, 1800.52 mg/l, respectively. The results of microscopic histology of gill samples in different treatments revealed some damages such as hyperemia, hyperplasia, elongation of secondary lamellae, cell necrosis and adhesion of secondary lamellae.