Have a look at this article. Good luck.

The Clarias gariepinus is one of the most extensively cultured fish in tropical and subtropical conditions due to its ability to satisfy aquaculturist and consumer needs; consequently, these fish are regarded as a promising candidate model for toxicological studies and monitoring of pollutants released into aquatic environments. The exposure of these fish to 4-NP affects multiple systems, including the endocrine, reproductive, haematological, and metabolic systems. 4-NP is classified as highly immunotoxic because it downregulates genes associated with immune reactivity, induces pro-inflammatory mediators, and upregulates genes associated with the production of reactive oxygen and nitrogen species.