title: Effect of repeated application of fenthion as a mosquito larvicide on Nile tilapia (Oreochromis niloticus) inhabiting selected water canals in Sri Lanka.
abstract: Health status of feral Nile tilapia following repeated applications of fenthion as a mosquito larvicide to selected water canals in Sri Lanka was assessed. With three spray applications of fenthion to the study sites at weekly intervals at the concentration recommended for mosquito control, condition factor and brain acetylcholinesterase activity of the fish were depressed in a time dependent manner. Prominent histopathological alterations displayed were gill hyperplasia and telangiectasis and vacoulation of hepatocytes. Observed ill health effects of fenthion on the fish demonstrate probable ecological risk to the fish populations inhabiting the water canals which receive repeated inputs of fenthion.
authors.affiliation: Department of Zoology, University of Kelaniya, Kelaniya, Sri Lanka.
authors.forename: Viranga K
authors.initials: VK
authors.lastname: Jayasundara
authors.forename: Asoka
authors.initials: A
authors.lastname: Pathiratne
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology; D001923:Brain Chemistry / Q000187:drug effects; D023681:Cichlids / Q000502:physiology*; D009033:Culicidae; D005284:Fenthion / Q000633:toxicity*; D005618:Fresh Water; D005880:Gills / Q000473:pathology; D022781:Hepatocytes / Q000473:pathology; D007300:Insect Control; D007306:Insecticides / Q000633:toxicity*; D007814:Larva; D008099:Liver / Q000473:pathology; D013188:Sri Lanka; D013684:Telangiectasis / Q000139:chemically induced / Q000473:pathology
chemical_list: D007306:Insecticides; D005284:Fenthion; D000110:Acetylcholinesterase