Effects of Glyphosate Herbicide on Serum Growth Hormone (GH) Levels and Muscle Protein Content in Nile Tilapia (Oreochromis Niloticus L.)

Abstract

2 Abstract: Glyphosate herbicide is one the most toxic pollutants for aquatic ecosystem. Changes in serum concentrations of growth hormone (GH) and muscle protein content in O. niloticus treated with different concentrations of glyphosate herbicide under laboratory conditions were evaluated. Nile tilapia Oreochromis niloticus (mean initial weight of 57.61 ± 4.8g and initial length 14.87±1.7cm) were exposed to different concentrations of Roundup, a glyphosate (acid equivalent) herbicide: 0 (control), 1, 3, and 5 mg/L for 96 h (short-term) of exposure. Unexposed fish (control) exhibited significantly higher serum GH levels (p<0.05) compared to treated fish. The GH levels and muscle protein content decreased significantly with increasing glyphosate concentrations. GH levels and muscle protein percentage may be the good early indicators of herbicide contamination in tilapia species. Key W ords: Glyphosate, herbicide, Oreochromis niloticus, GH, muscle protein.