Behavioural and Some Physiological Assessment of Glyphosate and Paraquat Toxicity to Juveniles of African Catfish, Clarias gariepinus

Abstract

The impact of acute exposure of Clarias gariepinus juveniles to commonly used herbicides, glyphosate and paraquat was evaluated through changes in fish behaviour and mortality. Juveniles of the African catfish were exposed to varying acute concentrations of glyphosate and paraquat. The fishes responded, exhibiting different behavioural abnormalities like hyperactivity, abnormal swimming, restlessness, loss of equilibrum and haemorrhage. Observation of opercular ventilation count (OVC), tail fin movemant rate (TMR) and air gulping index (AGI) showed a marked difference between control and exposed fishes, indicating that the herbicides negatively impact on these parameters. These behavioural and morphological anomalies became more pronounced with increasing concentrations of the herbicides. Mortality was also observed to be concentration dependent. After 96 h of exposure, the 96hr LC 50 for paraquat was found to be 0.07mg/L while that of glyphosate was found to be 0.530mg/L. The result revealed that glyphosate and paraquat have the ability to induce unusual behaviours in fish and can therefore serve as reliable indicators of toxicity in environmental impact assessment programmes.

Behavioural and physiological assessment of juveniles of African catfish (Clarias gariepinus) experimentally challenged with paraffin oil

“…This low response to feed might cause loss of weight, emaciation and death of the sh species at prolonged exposure to this pollutant. Reduced feed intake recorded in this study corroborates the ndings of Isaac et al (2017) and Melefa et al (2020), who documented a decline in feed intake of cat sh exposed to Glyphosate and Clotrimazole, respectively. However, this nding contradicts the assertion of Ayotunde et al ( 2011), who reported a similar feeding pattern between adults of C. gariepinus exposed to Carica papaya and those groups not exposed to the same pollutant.…”

“…The Clarias gariepinus exposed to the different sub-lethal concentrations of para n oil were observed for their behavioural responses at 24-hours intervals immediately after the renewal of the stock solution in each treatment during the experimental period, as described in Isaac et al (2017). Each treatment was observed for 10minutes every 12 hours by one investigator to eliminate bias using the focal sampling technique.…”

“…Oil spills in water bodies can cause sh to be suffocated by preventing oxygen from dissolving in it; it can also cause di culty in respiration, interference with the functioning of various organs, abnormal behaviour, and the death of the sh (Gabriel et al, 2007;Almeda et al, 2013;Nwani et al, 2013). Fish living in a polluted environment might ignore food and thus keep absorbing their bodies, reaching severe and mortality levels over a continuous period of exposure (Isaac et al, 2017;Melefa et al, 2020).…”

Acute Toxicity of Herbicides on the Survival of Adult Shrimp, Artemia Franciscana

“…Glyphosate is a non-selective herbicide that is generally used in agriculture for the control or destruction of herbaceous plants by altering their protein synthesis [6]. Also, this herbicide is used in fish-ponds, lakes, canals and slow running waters [7].…”

“…Also, this herbicide is used in fish-ponds, lakes, canals and slow running waters [7]. Due to changes in metabolic, oxidative and hematological factors, glyphosate is able to change the biological stability and cause damage to non-target organisms [6,7].…”