UTTAR PRADESH JOURNAL OF ZOOLOGY

The nicotine concentration is increasing in aquatic ecosystems daily. This is due to anthropogenic activities like consuming nicotine-based products like cigarettes. Nicotine gets leached out of these spent or used cigarettes and can enter the aquatic system. This directly induces adverse effects on aquatic animals. During the four days of acute toxicity analysis, all the Labeo rohita fingerlings died when exposed to surface waters concentration of nicotine (9.34 mg/L). Hence, the current study aimed to evaluate the impact of a sub-lethal concentration of 0.93 mgL^-1 of nicotine, i.e., 1/10^th of surface waters concentration of nicotine (9.34 mg/L), on growth performance and biochemical markers in Labeo rohita fingerlings. The fish were exposed to 0.93 mgL^-1 of nicotine for 60 days. During the experiment, growth performance and biochemical markers were noticed at different intervals, i.e., 15^th, 30^th, 45^th and 60^th days. The growth performance, such as net weight gain, length gain, specific growth rate and condition factor, significantly declined. In contrast, the feed conversion and feed efficiency ratios were remarkably increased compared to control fish. Further, the protein, glycogen and lipid levels notably declined, and increased amino acid content in the liver and muscle of sub-lethal concentration nicotine-exposed fish was observed. The results displayed that 1/10^th of the surface concentration of nicotine can potentially reduce the growth and alter biochemical markers in Labeo rohita fingerlings.