Authors : U.U. Gabriel , P.E. Anyanwu and A.O. Akinrotimi
Abstract: A study was carried out to compare the effects of different acclimation media (brackish water, gradual reduction in salinity and direct transfer to fresh water) on haemotological parameters of Sarotherodon melanotheron. Six hundred and thirty S. melanotheron (mean weight 30.12 g�0.32 SD; mean total length 10.22 cm 0.14 SD) were sampled from recruitment ponds of African Regional Aquaculture (ARAC) Brackish Water Fish Farm, Buguma and Rivers State and acclimated in three different methods for seven days. Before acclimation the blood sample were taken, with mean values of Haemoglobin (Hb) 6.44�0.43 g L 1; Haematocrit (Ht) 20.80�0.43%; Leucocrit (Lct) 6.93�0.29%; white blood cells 29.84�0.07�109 cell L 1, Red Blood Cell (RBC) 2.53�0.03�1012 cell L 1; Mean Corpuscular Haemoglobin Concentration (MCHC) 31.36�0.98 g L 1; Mean Corpuscular Haemoglobin (MCH) 25.60�0.81pg; Mean Corpuscular Volume (MCV) 81.16�1.80 f L; Platelets 173.43�3.46%; Neutrophils (Neut) 35.81�0.85% Lymphocytes (Lymp) 46.09�1.01%; Monocyte (Mon) 2.25�0.01%. Differences between male and female (p< 0.05) before acclimation were recorded in Hb, Ht, RBC, Plt. The values of the blood parameters in the female were consistently higher than that of the male. There was reduction (p< 0.05) in Hb, Ht, Lct, RBC, Plt and Lymp after while WBC, MCHC, MCH, MCV, Neut and Mon increased. These variations were more in males and more pronounced in S. melanotheron acclimated in fresh water. The study suggests that method of acclimation affects the blood characteristics of S. melanotheron and that where the fish is to be cultured in or acclimated to fresh water environment the best method should be by gradual salinity reduction. The latter method seemed to allow the fish system to adjust gradually to fresh water challenge with minimal impact on the blood characteristics.
U.U. Gabriel , P.E. Anyanwu and A.O. Akinrotimi , 2007. Comparative Effects of Different Acclimation Media on Haematological Characteristics of Brackishwater Tilapia, Sarotherodon melanotheron (Rupell, 1852) . Journal of Fisheries International, 2: 195-199.