Toxicity Of Monotrim to Clarias Gariepinus Juveniles (Burchell, 1822): A Named Antibiotic

Abstract

The study is aimed at assessing the toxic effects of trimethoprim on juvenile sharptooth catfish (Clarias gariepinus). One hundred and eighty (180) juvenile catfish with length of 9 to 10cm were exposed to trimethoprim concentrations grouped into to six treatments category of 0.00 mg-L (control), 50 mgl, 100 mgl, 150 mgl, 200 mgl, and 250 mgl having two replicates each for a short acute toxicity test of 96 hour period. Ten Clarias gariepinus were placed in a rectangular aquaria for 21 days acclimatization period, trimethoprim was introduced into the fish holding tank prior to start of experimental observation, the juveniles measuring about the size of the human finger were however fed with 30% crude protein diet. Test specimens subjected to concentrations of 150 mgl, 200 mgl, and 250 mgl of trimethoprim revealed a predictable unperceptive, aggressive and inconsistent behavioral movements.  At concentration of 0.00mgl referred to as the control, 50, and 100mgl no mortality was recorded, while mortality rate was at 25, 50 and 75% for samples exposed to trimethoprim concentration of ≥150mgl of trimethoprim. Fish mortality was dependent on antibiotic concentration as well the effect of exposure-time. The lethal concentration (LC₅₀) of this short acute toxicity test at 95% confidence limit was 165 ± 0.046mgl, indicating low toxicity. A dose-dependent relationship was reflected in the examined gills tissue. This paper revealed that antibiotics are harmful to aquatic resources particularly fish which form daily meal for man, hence, pose health challenges.