Morpho-behavior Changes in Fish Exposed to Malathion: An Ecotoxicological Study

Abstract

Behavioral changes are key indicators in ecotoxicology, revealing the impact of
toxic environments on aquatic organisms. This study investigated the effects of malathion, a
common pesticide, on the behavior of Heteropneustes fossilis. Fish exposed to malathion
showed significant behavioral changes within 30 minutes, including loss of equilibrium, erratic
swimming, and increased speed. Morphological changes, such as skin discoloration, chemical
deposition, and lesions, were also noted. Behavioral symptoms progressed with higher
concentrations and longer exposure, leading to increased activity, air gulping due to hypoxia,
and reduced resting periods. Severe symptoms, including lethargy, unresponsiveness, and
extensive skin peeling, emerged over prolonged exposure. Acute toxicity testing revealed
immediate surfacing behavior followed by lethargy and signs of asphyxiation. The study
concludes that malathion exposure disrupts normal behavior, likely due to stress and
biochemical changes, highlighting the pesticide's ecological impact.