Sublethal effect of glyphosate [n-(phosphonomethyl)glycine] on growth performance and biochemical activities in some organs of Clarias gariepinus (Burchell, 1822) fingerlings

• Main Authors: Adedamola Oladapo Akinbadewa, Henry Adefisayo Adewole, Victor Folorunso Olaleye, Gbenga Emmanuel Ogundepo
• Format: Article
• Language: English
• Published: Estonian Academic Agricultural Society 2020-12-01
• Series: Agraarteadus
• Subjects: glyphosate; enzyme; tissue, growth; sub-lethal toxicity; clarias gariepinus
• Online Access: http://agrt.emu.ee/pdf/2020_2_akinbadewa.pdf

The effect of the sublethal concentration of glyphosate [N-(phosphonomethyl)glycine] on growth and some biochemical indices in the organs of African catfish (Clarias gariepinus, Burchell 1822) fingerlings in a static bioassay setup was studied to provide information on the sublethal toxicity effect of glyphosate on C. gariepinus fingerlings. Two hundred and seventy (270) fingerlings of C. gariepinus (10.02 ± 0.20g) randomly stocked at 30 fish per tank in triplicate were exposed to varying concentration (0, 2.75 ppm and 5.00 ppm) of glyphosate for 70 days. The results of the study showed that the determined growth parameters decrease with increase glyphosate concentration (except specific growth rate). The highest mortality rate was recorded in the treatment with the highest phosphate concentration (5.50 ppm). The enzymatic analyses of the fish tissue revealed that Na+/K+-ATPase activity which ranged from 0.20 to 19.29 µM Pi min–1 mg–1 protein in all the fish tissues increase with increase glyphosate concentration in the fish muscle and liver, and decreases with increase in glyphosate concentration in the gills. However, the muscle and liver malate DH activities decreased with increase in glyphosate concentration while the lactate DH activity increases with increase intoxicant concentration in the muscle (with the highest treatment having a threefold increase). Generally, the enzymatic activities of fish tissues followed the order: Malate DH >Na+/K+-ATPase>Lactate DH. The study concluded that the glyphosate concentration negatively impacted the growth and survival of C. gariepinus and also had a pronounced effect on the enzymatic activities of the studied organs.