Introduction: Water is an important resource that is essential for health, household use, agriculture, transportation, ecological as well as many other anthropogenic activities. But as essential as it is, water is also one of the most poorly managed resources, often contaminated with varieties of pollutants, with potential threat to human and aquatic wildlife. These pollutants include those from industrial activities as well as agrochemicals and environmental pesticides including insecticides, fungicides and herbicides that are majorly from agriculture
Aims: The toxicity status of many of these pesticides on wildlife is unknown, and this lacuna is very important to be filled.
Materials and Methods: Following OECD, (2012) fish toxicity protocol, 96-hour acute toxicity of Diquat dibromide formulation was assessed against African catfish (Clarias gariepinus) at both fingerlings and juvenile stages. The exposure concentration ranged from 2.5-11 mgL-1.
Result: The result of this showed that percentage mortality increased relative to the concentration at both developmental stages. The 96-hour lethal concentration was 8.66 mgL-1 and 2.65 mgL-1 for fingerlings and juvenile stage respectively. This means that although Midstream formulation is moderately toxic to both the juvenile and the fingerling stage, the fingerlings is more susceptible to the formulation.
Conclusion: This level of susceptibility within the developmental stages could have long term impacts on the population dynamics of this fish species. This result is essential as it shows the importance of selecting appropriate developmental stage for toxicity evaluation. Therefore, application of Midstream formulation should be restricted away from aquatic system where this fish species or others with similar physiological and ecological characteristics could be found.