Haematological Response of<i> Clarias gariepinus</i> to Bacterial Infection and Prophylactic Treatment with Antibiotic

Abstract

A total of thirty Clarias gariepinus were used for the experiment. Ten C. gariepinus of 357.76 g mean weight were artificially challenged by injecting 2 ml each of live Pseudomonas fluorescences suspended in Ringers solution and containing 12.5 x 105 bacterial cells (3.5 x 105 cells/g wt) respectively. They were prophylactically treated by injecting 1ml each of Chloramphenicol (1g in 10 ml distilled water). Another ten C. gariepinus of 270.51 g mean weight were also challenged by injecting 2 ml each of live P. fluorescens in Ringers solution containing 12.5 x 105 cells (4.6 x 103 cells g/wt) without any prophylactic treatment. Finally, another ten C. gariepinus of 267.8 g mean weight which served as the control, were injected with 2ml Ringer's solution only. 60% mortality among the infected and treated fish was recorded, 80% mortality among infected and untreated C. gariepinus while no mortality was observed for the control. Some haematological indices revealed that the infected and treated fish had haematocrit (25.3 ± 1.883%), Erythrocyte sedimenutation rate (5.25 ± 1.192 mm/h), Mean Haemoglobin (5.2 + 0.48 g/100cm3), and white blood cells (11.33 x 103m3). The infected and untreated fish had haemalocrit (22.8 ± 3.61 %), ESR (5.9 ± 0.38 mm/h), mean haemoglobin (5.6 + 0.25 g/100cm3) and WBC (13.52 x 103/mm3), while the control fish had haemalocrit (31.0 + 3.24%), mean ESR (5 ± 2.05 mm/h), mean haemoglobin (6.9 ± 0.85 g/100cm3) and mean WBC (7.54 x 103/mm3).


Journal of Aquatic Sciences Volume 16, April 2001, pp. 22-24



KEY WORDS:

Haematology, Clarias gariepinus and prophylactic treatment