RESUMEN
Pisces are commonly used to study the effects of metals, including copper on the environment. However, until now only scant information is available about the responses induced by waterborne copper during early life stages and housekeeping gene expression in fishes. In the present study, we evaluated acute toxicity of copper sulphate on larvae of Catla catla and also the stability of expression of three housekeeping genes, beta-actin (β-actin), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and elongation factor 1 alpha (EF1α). The results have shown increased mortality of Catla catla larvae with the increased concentration of copper sulphate. The median lethal concentration (LC50) of copper sulphate at the end of 96 h exposure was 1.032 ppm. During the challenge test of copper sulphate, the minimal coefficient of variation (CV) and stability index were observed for GAPDH and maximum for β-actin indicating minimum variation of GAPDH and maximum variation of β-actin. With the results, it can be concluded that GAPDH is most stable during copper sulphate challenge test on Catla catla larvae, followed by EF1α and β-actin.