Ciências Marinhas: Pesquisa e Desenvolvimento

Abstrato

Effect of 17 a-Methyl Testosterone on Haematology and Histology of Liver and Heart of Oreochromis andersonii (Castelnau, 1861)

Kefi AS, Kang’ombe J, Kassam D and Katongo C

The aim of the study was to investigate the effect of 17 α-methyl testosterone (MT) on haematology and histology of liver and heart of Oreochromis andersonii subjected to varying levels of MT. Three different doses (40, 60 and 90 mgMT/kg feed) of MT were administered to O. andersonii. Final mean weight (g), gonadosomatic, cardiosomatic and hepatosomatic indices did not differ (P>0.05) among the treatments. Similarly, survival of the O. andersonii in all the treatments did not differ (P>0.05) significantly. Of the haematological and blood chemistry parameters determined, only haemoglobin (Hb), red blood cells (RBC), haematocrit and uric acid were significantly different (P<0.05), among the treatments with the control group having the highest of the latter two parameters. Haemoglobin (r=-0.743; P<0.05) and Red Blood Cells (RBC) (r=-0.726; P<0.05) showed significant association with MT levels. All the treatments did not show any histopathological differences in the liver and heart. However, all the liver samples showed haemosidrein (HE) and extra–hepatic pancreas (EH), while the heart exhibited the vacuolar degeneration (VD). The length–weight relationship coefficient differed (P<0.05) among the treatments with the fish fed with 40 mgMT/kg having the highest slope (2.642), although it only differed (P<0.05) with that of 90 mgMT/kg (1.547), which exhibited the worst condition. The study shows that the oral administration of MT for a short period of up to thirty (30) days does not affect the physiology of O. andersonii. Furthermore, the safety of MT to O. andersonii is, therefore, proved under the conditions of the current experiment. However, there are signs of condition deterioration in high levels of MT.