Labeo rohita fingerlings exposed to titanium dioxide (TiO2 NPs): A concentration-dependent bi-modal effect on growth

Abstract

Titanium dioxide nanoparticles (TiO2-NPs) are widely manufactured and can be released into the environment, where they have the potential to severely affect fish and human health. This study was conducted to evaluate the effect of TiO2-NPs on the growth of fingerlings of Labeo rohita. TiO2-NPs were used in different concentrations (1 mg/kg, 10 mg/kg, 100 mg/kg and 1000 mg/kg) mixed in fish basal feed for a period of 12 weeks. The mortality rate was recorded once the fish were acclimatized, after TiO2-NPs exposure. The growth in length (cm) and weight (g) of the fish was measured to evaluate the time and concentration dependent growth of the fingerlings. A high mortality rate was observed for the fish exposed to high concentrations of TiO2-NPs from week 10 onwards. A gradual increase in the body weight and length of the fish was observed for all treatments until the 8th week, which thereafter changed differently for different treatments. It could be shown that TiO2-NPs exert concentration dependent bi-modal effects on fish growth with a longer exposure to high concentrations of TiO2-NPs having an adverse effect on the growth. Therefore, TiO2-NPs in natural water bodies may affect the aquaculture industry as well as inland fisheries.