Endocrine Disrupting Potential Of The Sub-Lethal Concentrations Of Primextra Herbicide On The Hormonal And Heamatological Profile Of Clarias Gariepinus (Burchell, 1822) Sub-Adults

Abstract

The application of primextra on farmlands to curb weed growth contaminates water bodies, thereby resulting
in endocrine disruptions in aquatic organisms. The sub-adults (n = 200) of Clarias gariepinus were exposed
to 0.00 (control), 0.07, 0.14, 0.21, and 0.28 mg/L of primextra, and the hormonal and haematological
alterations were observed over a period of 28 days. The alterations in the hormonal and haematological profile
of the exposed fish was concentration dependent. The thyroxine (T4), tri-iodothyronine (T3), and estradiol
(hormonal parameters) reduced significantly (p<0.05) compared to the control with increase in the
concentration of the toxicant after four weeks of exposure. The T4, T3, and estradiol concentration decreased
with increase in the exposure duration for the 0.07, 0.14, 0.21 and 0.28 mg/L group. The haemoglobin (Hgb),
pack cell volume (PCV), red blood cells (RBC), white blood cells (WBC), mean corpuscular volume (MCV),
and mean corpuscular heamoglobin concentration (MCHC) decreased significantly (p<0.05), while the mean
corpuscular haemoglobin (MCH) increased significantly (p<0.05) from the control with increase in the
concentration of the toxicant after four weeks of exposure. The Hgb, PCV, RBC, WBC, and MCV decreased,
while MCH and MCHC in the fish increased with increase in the exposure duration for the 0.07, 0.14, 0.21
and 0.28 mg/L group. With the observed alterations in the hormonal and haematological parameters in the fish
exposed to primextra, indiscriminate use of chemicals on farms is highly discouraged, in order to maintain a
healthy terrestrial and aquatic eco-system, including our fishery resources and man.