ĐÁNH GIÁ ĐỘC TÍNH CỦA DỊCH CHIẾT TỪ CÂY DÂY GẮM (Gnetum montanum) TRÊN CÁ TRA (Pangasianodon hypophthalmus) GIAI ĐOẠN GIỐNG

Medicinal plants are increasingly being researched and widely utilized in aquaculture; however, certain herbs also possess inherent toxicity. The current study assessed the toxicity of extracts from Gnetum montanum and determined the concentration or dose causing 50% mortality (LC50/LD50) in striped catfish through immersion and oral administration. Striped catfish fingerlings (~10 g) were exposed to water containing various extract concentrations (800; 1,000; 1,200; 1,400, and 1,600 mg/l), while the oral gavage method involved doses of 350, 450, 550, 650, and 750 mg/kg fish. Mortality rates were observed at 24, 48, 72, and 96 hours. The results showed that Gam extract was toxic to striped catfish fingerlings. The LC50 after 24, 48, and 72/96h were 1,114.81; 1,100.56; and 1,046.62 mg/l, respectively; the LD50 was 562.83 mg/kg fish after 48h and 518.23 mg/kg fish after 72/96h. Safe concentrations were below 111.48, 110.06, and 104.66 mg/l after 24, 48, and 72/96h, respectively; safe doses were below 56.28 mg/kg fish after 48h and 51.82 mg/kg fish after 72/96h. Fish exhibiting signs of toxicity showed pronounced alterations in the morphology and coloration of internal organs such as the gallbladder, liver, spleen, kidney, and heart. Observed changes included congestion, discoloration, and deformation, indicating significant physiological impacts of the toxic compounds on internal organ function.