ORIGINAL RESEARCH article
Front. Toxicol.
Sec. Environmental Toxicology
This article is part of the Research TopicEnvironmental Toxicity in MetabolismView all 4 articles
Ecotoxicological Thresholds of Glyphosate: Linking Sub-Lethal Exposure to Liver Tissue Damage and Behavioural Disturbances in African Catfish
Provisionally accepted
Bethel Uchenna Udume1*
Anyaele Uka1Glory Nnenna Oji1Chieze Precious Chikezie2Chidi Onyewuchi3Obiahu Henry Ota4- 1Michael Okpara University of Agriculture, Umudike, Nigeria
- 2Alex Ekwueme Federal University Ndufu-Alike, Ikwo, Nigeria
- 3College of Fresh Water Fisheries New bussa, Niger, Nigeria
- 4The University of Waikato Environmental Research Institute, Hamilton, New Zealand
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
The behavioural response and liver alterations of Clarias gariepinus exposed to varying concentrations of glyphosate herbicide were studied. Clarias gariepinus were assessed in a static renewal bioassay for 96 hours. The LC50 established was 1.50 mg/l. Sub-lethal concentrations 0.30 mg/l, 0.50 mg/l, 0.70 mg/l and 1.00 mg/l were used during the study. The physico-chemical parameters monitored were temperature, pH, dissolved oxygen and electrical conductivity. At various concentrations, the fish showed abnormal behavioural responses which include irregular swimming pattern, loss of reflexes, startle responses, changes in colour pigmentation, frequent surfacing, reduced feeding and lethargy. The behavioural abnormalities of the fish became intense with increasing concentrations of toxicants. Dissolved oxygen and pH decreased significantly with increasing glyphosate concentration, while electrical conductivity increased. Histopathology of liver tissue was examined in this study. At concentrations of 0.30 mg/l lesions and vacuolation of the hepatocytes were observed; 0.50 mg/l showed haemorrhages and coagulative necrosis; 0.70 mg/l showed liquefactive necrosis (ln), cytoplasmic vacuolation (v), hepatic cells damage (hcd) and blood congestion (bc); 1.00 mg/l of the toxicants showed v: vacuolation, dh: disarrangement of hepatocytes cell membrane, bc: blood congestion in hepatocyte and cs: congested sinusoids while the control (0.00 mg/l) showed typical structure of the hepatocytes. These findings showed that 0.30 mg/l to 1.00 mg/l of the toxicants caused alterations in the liver tissues and behavioural of the fish thereby posing potential ecological risks to freshwater fish in contaminated aquatic systems. The study highlights the need for constant monitoring and stricter management of glyphosate use to safeguard aquatic ecosystems.
Keywords: Clarias gariepinus, Liver histopathology, Pesticides, Physicochemical parameters, Sub-lethal toxicity
Received: 20 Dec 2025; Accepted: 09 Feb 2026.
Copyright: © 2026 Udume, Uka, Oji, Chikezie, Onyewuchi and Ota. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Bethel Uchenna Udume
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.