Toxic Effects of Fungicide Sheathmar to Worm, Tubifex Tubifex

Abstract: The current study sought to determine Sheathmar's acute toxicity as well as its sublethal effects on oxidative stress enzymes in Tubifex tubifex, a benthic oligochaete worm. The results showed that the 96-hour median lethal concentration (LC50) of Sheathmar for Tubifex tubifex is 3186.3 µg/l. According to the model fit performance, the GUTS-SD model can better predict the survival rate of Tubifex tubifex. Sublethal Sheathmar concentrations (10% and 20% of the 96h LC50) significantly changed the oxidative stress enzymes. Reduced glutathione (GSH), glutathione S-transferase (GST), and glutathione peroxidase (GPx) activity all showed a significant initial increase followed by a decline, whereas catalase (CAT) activity and malondialdehyde (MDA) levels increased significantly with increasing Sheathmar concentrations at all exposure times. Furthermore, the effects of Sheathmar on Tubifex tubifex were demonstrated by the development of a potency index and the assessment of integrated biomarker response (IBR). These findings suggest that exposure to Sheathmar influences Tubifex tubifex survival at the acute stage and modifies oxidative stress enzyme alterations at the sublethal level