Pyriproxyfen toxicity to fish and crustaceans: A literature review

Pyriproxyfen (PPF) is an insect growth regulator (IGR) that acts as a juvenile hormone agonist (JHA). It is widely used as a larvicide to control insect vectors, as antiparasitic medicines, and for pest control in domestic and agricultural environments. Reports in the literature show that PPF is toxic to fish and non-target crustaceans. Therefore, this review aimed to compile and analyze the state of the art on PPF toxicity to fish and crustaceans. We conducted a comprehensive and critical review by searching combinations of English keywords on the main scientific databases. The articles were selected based on inclusion and exclusion criteria. The findings demonstrated that exposure to different concentrations of PPF can have toxic effects on fish and crustaceans, resulting in histopathological damage to vital organs, reproductive dysfunction, and genetic changes. In crustaceans, PPF caused changes in fecundity, increased male production, and induced changes in offspring. In fish, histopathological changes were identified in organs such as the heart, liver, kidneys, brain, and gonads. Regarding reproduction, an increase in spermatogonial cysts in the testicles was reported, as well as the occurrence of atresia of oocytes in the female gonads. Furthermore, changes in the activity of antioxidant enzymes, the presence of reactive oxygen species indicating oxidative stress and alterations in the expression of genes related to thyroid and growth hormones were induced by exposure of fish to PPF.