Effect of Castor (<i>Ricinus communis</i>) Seed Oilon the Haematological Parameters of Nile Tilapia <i>Oreochromis niloticus</i> (Linnaeus, 1758)

Purpose: Nile tilapia is known to have a high prolific rate of reproduction which impacts the native aquatic bio-diversity. This phenomena and various methods of curtailing have been well studied in few selected places around the world. Hence, this research aims to evaluate the effect of castor oil on haematological parameters of O. niloticus, at sub-lethal doses. Research Method: Sixteen samples of ready to spawn O. niloticus weighing 6.5-8.5g were used for the experiment and castor oil was extracted from the seeds through Soxhlet extraction. Three different doses of castor oil (R. communis) were administered to determine the level of effect of castor oil on the blood parameters. Findings: Packed cell volume (PCV), haemoglobin (Hb), red blood cell (RBC) count, total white blood cell (TWBC) count, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were determined using standard methods. MCV, MCH, MCHC, and WBC did not vary significantly (P>0.05). PCV were all within the normal range (40.33-21.00%). Hb values were low and ranged from 6.97 – 13.43 g/dl, and TWBC ranged from 3.90 – 6.70 1012/l. Value: This research revealed castor oil to significantly alter some parameters of O. niloticus and has inverse relationship between WBC and RBC counts of O. niloticus.