Acute Toxicity of Cypermethrin on Nile Tilapia Fry

Anan Kenthao, Wanchat Sirisarn, Pornpimol Jearranaiprepame



          Fry of nile tilapia Oreochromis niloticus (Linnaeus, 1758) which were 30 days of age were used for toxicity bioassay of cypermethrin. The lethal concentration at 50 percent (LC50) and 70 percent (LC70) were 32.496 and 40.311 ppb, respectively. The exposure fish were determined at 24, 48, 72 and 96 hours.  The fish behaviour and histological alteration were observed in fish affected with cypermethrin at both LC50 and LC70. The affected fish exhibited the loss of equilibrium with erratic and darting swimming movements, hyperactivity, secretion of mucous and increasing rate of opercula activity. The changes of gill tissues included the swelling of epithelial cells and the fusion of secondary lamella. An enlargement of sinusoids, pyknotic nuclei, vacuole formation and degeneration in hepatic parenchyma were observed in the liver.  The degeneration of glomerulus combining with oedema of renal tubule was also noticed in the kidney.  No alter lesion was seen on skin tissue. Severity of lesion was related to concentration and time of exposure.


Toxicity bioassay, lethal concentration, histopathological alteration


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Online ISSN: 2228-835X

Last updated: 20 June 2019