Effect of Brief Exposure to Paraquat on Some Blood Parameters of Juvenile <i>Clarias gariepinus</i> (Burchell, 1822) under laboratory conditions

Abstract

Clarias gariepinus (mean weight, 100.34 ± 8.13g SD; mean total length, 19.02 ± 4.32 cm SD) were exposed (four fish/tank) to 0, 1.25, 2.50 and 5.00 mgl-1 paraquat solution in triplicate in rectangular glass aquaria (60.9 x 30.4 x 30.4 cm3) under a static
condition for 72 hours to determine the effect of exposure on the haemoglobin (Hb), haematocrit (Ht), erythrocyte sedimentation rate (ESR), red blood cells (RBC) and its indices (mean corpuscular hacmoglobin, MCH; mean corpuscul or hacmoglobin concentration, MCHC and mean corpuscular volume (MCV)), differential counts (neutrophils, monocytes,
lymphocytes, basophils and eosinophils) and leucocrit. There were no significant differences between the Hb, Ht, RBC, ESR, lymphocytes, monocytes and MCV of exposed fish and the control (p>0.05). However, there was a gradual increase in the values of Hb with increase in the concentration of the herbicide. The RBC indices MCH and MCHC of fish in the
control significantly differed from that of fish exposed to 2.50, and 1.25 mgl-1, and 2.50 mgl-1 paraquat (p<0.05), respectively. Results from the study suggest that brief exposure of juvenile C. gariepinus to paraquat could cause some level of stress as manifested by changes in some of the haematological parameters of the fish studied

Keywords: Clarias gariepinus, blood parameters, paraquat, laboratory conditions.

Discovery and Innovation Vol. 19 (3) 2007: pp. 163-167