Abstract:

To investigate the molluscicidal activity, hepatotoxic effects, and environmental toxicity of extracts from Asclepias curassavica, Phytolacca americana, and Cicuta virosa against Pomacea canaliculata, the present study systematically evaluated their effects at varying concentrations and exposure times based on an immersion method. Key hepatic physiological indicators and residual toxicity in water were also measured. All three plant extracts exhibited dose- and time-dependent molluscicidal effects. A. curassavica demonstrated the highest toxicity (48 h LC₅₀=0.270 mL/L), being 3.03 times and 3.97 times more potent than P. americana (0.819 mL/L) and C. virosa (1.071 mL/L), respectively. Physiological indicators in the hepatopancreas indicated that toxic damage induced by A. curassavica and C. virosa was the most pronounced. This was reflected by a decrease in the levels of biomarkers associated with organismal damage, such as total protein (TP), malondialdehyde (MDA), and catalase (CAT), alongside an increase in activities of enzymes closely related to hepatic detoxification function, including acetylcholinesterase (AChE), glutathione S-transferase (GST), and alanine aminotransferase (ALT). Residual aquatic toxicity results demonstrated that A. curassavica caused the highest inhibition rate in luminescent bacteria (75% at LC₇₅), whereas P. americana posed the lowest ecological risk (56% inhibition rate). Compared to traditional chemical molluscicides, the A. curassavica and P. americana extracts exhibit higher ecological safety, rendering them more suitable for eco-friendly control applications and demonstrating significant potential for development as botanical molluscicides.

Key words: Pomacea canaliculata, plant extract, molluscicidal efficacy, hepatopancreas physiological index, residue toxicity test