Abstract:
Biochemical, haematological and biometric studies of the African lungfish, Protopterus annectens were carried out in order to establish their mean and reference values which would serve as baseline data for assessment of the health status of the fish as well as reference point for future comparative surveys. The study was carried out between March and August, 2015. In the present study, blood was analyzed using standard techniques, and differences in haematological parameters including haemoglobin concentration, red blood cell count (RBC), white blood cell count (WBC), packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were determined. Biochemical parameters such as alkaline phosphate (ALP), aspartate transaminase (AST), alanine transaminase (ALT), total protein, albumin, globuline, glucose, cholesterol level, and urea were determined. Biometric parameters such as condition factor (K), hepatosomatic index, and gonadosomatic index were also determined. These haematological, biochemical and biometric parameters of fish were compared according to sex and seasons. Analysis of variance showed that there were significant differences (P < 0.05) in ALP, AST, ALT, Protein, PCV, RBC, WBC, Hb and MCV, between sex and season. The results indicated that blood parameter level such as PCV, RBC, WBC, Hb, MCV, and MCHC between sexes in dry season were significantly different from those measured in wet seasons. The result also indicated that there were significant (P < 0.05) differences in condition factor (K), hepatosomatic index (HSI) and gonadosomatic index (GSI) between the seasons. There were no significant differences in MCH and MCHC values between the sexes. The values of WBC and PCV were found to be higher in female fish especially in dry season, while the level of haemoglobin and MCV values were higher in male Protopterus annectens. This may be related to the aggressiveness of the male fish. All the biochemistry parameters were higher in dry season except cholesterol and urea, but no significant differences were found among the sexes. The length of the fish varied significantly with season. The highest length was recorded in the March and June, while the highest mean weight frequency was obtained in the month of August. The length-weight relationship showed a negative allometric growth and the condition factor indicated that the fish were in a good condition in the months of April and July. There was increase in Hepatosomatic index (HSI), as the fish length increased. The results of the present study provide useful information for monitoring changes in the health status of fish.
