Toxicological Safety Assessment of Molluscicides Against Non-target Aquatic Biota; Colisa fasciatus

Abstract

Plants Terminalia arjuna and Tamarindus indica are known to have a significant molluscicidal potential to control the population of vector snails. Since the molluscicides are considered an emerging pollutant and are frequently detected in surface water bodies and found to be a great threat for aquatic biota. Hence, the main objective of this research is to critically evaluate the ectotoxicological and chronic effect of plant-derived molluscicides on other aquatic biotas. With these references this study deals with the safety measurement of molluscicides arjnolic acid, saponin and procynadine from T. arjuna and T. Indica against the fish Colisa fasciatus which share the same habitat with snails. The result of toxicity experiment reveals that fishes showed no mortality against 24h LC90 (against L. acuminata and I. exustus) up to 96h exposure duration. The enzyme bioassays of these molluscicides on the nervous tissue of fish showed no significant effect on key enzymes Acetylcholinesterase, acid and alkaline phosphates activity in comparison to control group of fishes. These results indicated that the application of arjunolic acid, saponin, and procynadine derive from plant T. arjuna and T. indica at its maximum concentration (24h LC90 of L. acuminata and I. exustus) and exposure duration (96h) did not cause any mortality or treatment-related enzymes inactivity in fishes. The study conclusively proved the ecotoxicological and chronic safety of plant-derived molluscicides arjunolic acid, saponin, and procynadine on non-target animals in the aquatic environment.