Selim Adewale Alarape

Introduction: Glyphosate is a non-targeted organophosphate insecticide whose solubility and mobility in hydrophilic solvents enable its rapid leaching into the soil and subsequent contamination of ground and surface water and possible build-up in the aquatic food chain. Based on the public health importance of glyphosate in fish through consumption, it is crucial to determine the current residue concentration in culture Clarias gariepinus species. The aim of the present study is to evaluate glyphosate’s residue concentrations and its metabolites in cultured African Catfish offered for sale in selected markets in Ibadan.Methods: A total of twenty-five (25) adult Clarias gariepinus (300 ± 50 g) were sourced from five (5) selected active fish markets (Ojoo, Iwo road, Eleyele, Challenge, and Apata) within the Ibadan metropolis. The collected fish tissue samples (liver, kidney, and spleen) were prepared for glyphosate residue concentration analysis using Liquid Chromatography (LC).Results: The results showed that glyphosate residues were recorded in all the seventy-five (75) fish tissue samples obtained from the selected fish markets in the Ibadan metropolis and all residue concentrations were above both the recommended Acceptable Daily Intake (ADI) of 1.0 mg/kg (1 × 10⁻³ mg/L) and Maximum Residue Limits (MRL) of 0.01 mg/kg (1 × 10⁻⁵ mg/L). Isopropylamine has the highest residue concentration followed by N-Phosphonomethyl and Aminomethylphosphonic Acid (AMPA), while N-Acetyl Glyphosate has the least residue concentration across the sampled markets.Discussion: The presence of residues of glyphosate and its metabolites in ready-to-eat fish calls for holistic, systematic, and effective risk management strategies towards monitoring pesticide/herbicide usage in aquaculture production and ensuring the provision of wholesome fish and fish products for the consumers.

This toxicological study was carried out to determine possible adverse effects of Telfairia occidentalis and Ipomoea batatas leaves in Clarias gariepinus. Ninety-six Clarias gariepinus growers (431.25±6.13 g) randomly distributed into four feeding groups were fed with herbal leaf diet containing 20 g/kg of T. occidentalis (group A), 100 g/kg of I. batatas (group B), mixture of 10 g/kg of T. occidentalis and 50 g/kg I. batatas (group C) and basal diet (group D) which served as the control group. After a 40-day feeding period, blood samples were collected for serum biochemical assay and organs were harvested for antioxidant and tissue biochemical assay. A significant decrease in creatinine was observed in the fish in group C when compared with those in group D. Also, there was no significant difference in the liver superoxide dismutase activity across all feeding groups but no significant increase in the intestinal superoxide dismutase activity of the fish in group C when compared to those in group A. There were no significant differences in the values of liver enzyme markers and lipid profile across all feeding groups. However, a significant increase in the level of intestinal malondialdehyde was observed in the fish in group B when compared with those in groups A and D. This study revealed that oral administration of a combination of T. occidentalis (10 g/kg) and I. batatas (50 g/kg) leaves enhanced antioxidant enzymes and is recommended for protection against oxidative stress in Clarias gariepinus.

Background: Glyphosate, a brand of agricultural herbicides which intensive use has led to widespread contamination of different ecosystems. This study was designed to determine both organotoxicity and genotoxicity of glyphosate on African Catfish (Clarias gariepinus) exposed to different concentrations for 96 hours.Methods: Questionnaires were administered (physically and online) to determine the type of glyphosate-based herbicides mostly used by fish farmers. Seventy-five apparently healthy adult Clarias gariepinus (300g) were sourced from a local farmer, transported in a plastic keg to Fish and Wildlife Laboratory at the Department of Veterinary Public Health and Preventive medicine for two (2) weeks of acclimatization. After acclimatization, they were further divided into four (4) groups (T0 (Control), T1 (0.003ml/L), T2 (0.0045ml/L) and T3 (0.006ml/L)) by simple randomization and each group replicated into three (3) treatments. At the expiration of 96 hours of exposure, blood samples and organs (Gills, Kidney, and Liver) were collected for mononuclear assay and histopathological lesions respectively.Results: Exposed groups showed erratic swimming, splashing, and restlessness. Mortalities rate was dose-dependent (two (2) mortalities at 0.0045ml/L concentration (T2) and five (5) mortalities 0.006ml/L concentration (T3)). Observed histopathological lesions occurred at higher dose treatment (0.0045ml/L (T2) and (0.006ml/L) T3)) concentrations. The gills showed diffuse stunted and eroded secondary lamellae and severe congestion of the blood channel at the core of the primary lamellae. Lesions in the Liver include severe diffuse vacuolation of the hepatocytes, moderate to severe portal congestion and mild diffuse vacuolation of hepatocytes and moderate diffuse vacuolation of hepatocytes, and severe portal congestion. In the kidney, there was mild to moderate congestion of the interstitium and focus of interstitial oedema within the parenchyma. There was presence of micronucleus in the fish nucleated red blood cells at higher dose concentrations.Conclusion: This study showed that Glyphosate-based herbicides are highly toxic to Clarias gariepinus, therefore their use near the fish farm or in areas close to the aquatic environment should be discouraged. The agricultural community should also be conscious of the potentially adverse effects of pesticides. This is to prevent the water body from the residue of herbicides that would have washed down to the water.

Glyphosate, a brand of agricultural herbicides which intensive use has led to widespread contamination of different ecosystems. This study was designed to determine both organotoxicity and genotoxicity of glyphosate on African Catfish ( Clarias gariepinus ) exposed to different concentrations for 96 hours. Questionnaires were administered (physically and online) to determine the type of glyphosate-based herbicides mostly used by fish farmers. Seventy-five apparently healthy adult Clarias gariepinus (300g) were sourced from a local farmer, transported in a plastic keg to Fish and Wildlife Laboratory at the Department of Veterinary Public Health and Preventive medicine for two (2) weeks of acclimatization. After acclimatization, they were further divided into four (4) groups (T0 (Control), T1 (0.003ml/L), T2 (0.0045ml/L) and T3 (0.006ml/L)) by simple randomization and each group replicated into three (3) treatments. At the expiration of 96 hours of exposure, blood samples and organs (Gills, Kidney, and Liver) were collected for mononuclear assay and histopathological lesions respectively. Exposed groups showed erratic swimming, splashing, and restlessness. Mortalities rate was dose-dependent (two (2) mortalities at 0.0045ml/L concentration (T2) and five (5) mortalities 0.006ml/L concentration (T3)). Observed histopathological lesions occurred at higher dose treatment (0.0045ml/L (T2) and (0.006ml/L) T3)) concentrations. The gills showed diffuse stunted and eroded secondary lamellae and severe congestion of the blood channel at the core of the primary lamellae. Lesions in the Liver include severe diffuse vacuolation of the hepatocytes, moderate to severe portal congestion and mild diffuse vacuolation of hepatocytes and moderate diffuse vacuolation of hepatocytes, and severe portal congestion. In the kidney, there was mild to moderate congestion of the interstitium and focus of interstitial oedema within the parenchyma. There was presence of micronucleus in the fish nucleated red blood cells at higher dose concentrations. This study showed that Glyphosate-based herbicides are highly toxic to Clarias gariepinus , therefore their use near the fish farm or in areas close to the aquatic environment should be discouraged. The agricultural community should also be conscious of the potentially adverse effects of pesticides. This is to prevent the water body from the residue of herbicides that would have washed down to the water.

Background: COVID-19 is an emerging public health emergency of international concern. The trajectory of the global spread is worrisome, particularly in heavily populated countries such as Nigeria. The study objective was to assess and compare the pattern of COVID-19 spread in Nigeria and seven other countries during the first 120 days of the outbreak. Methods: Data was extracted from the World Bank’s website. A descriptive analysis was conducted as well as modelling of COVID-19 spread from day one through day 120 in Nigeria and seven other countries. Model fitting was conducted using linear, quadratic, cubic and exponential regression methods (α=0.05). Results: The COVID-19 spread pattern in Nigeria was similar to the patterns in Egypt, Ghana and Cameroun. The daily death distribution in Nigeria was similar to those of six out of the seven countries considered. There was an increasing trend in the daily COVID-19 confirmed cases in Nigeria. During the lockdown, the growth rate in Nigeria was 5.85 (R²=0.728, p< 0.001); however, it was 8.42 (R²=0.625, p< 0.001) after the lockdown was relaxed. The cubic polynomial model (CPM) provided the best fit for predicting COVID-19 cumulative cases across all the countries investigated and there was a clear deviation from the exponential growth model. Using the CPM, the predicted number of cases in Nigeria at 3-month (30 September 2020) was 155,467 (95% CI:151,111-159,824, p< 0.001), all things being equal. Conclusions: Improvement in COVID-19 control measures and strict compliance with the COVID-19 recommended protocols are essential. A contingency plan is needed to provide care for the active cases in case the predicted target is attained.

The Onderstepoort Journal of Veterinary Research (OJVR), is the official publication of the Onderstepoort Veterinary Institute. It publishes scientific papers reporting original research on diseases and disease vectors of livestock and wildlife with a focus on Africa, but with results of more than local interest.

Impact of industrial effluents on Alaro river in Oluyole industrial estate, Ibadan and its suitability for aquatic life