Organosomatic indices and histopathological response of Clarias gariepinus fed Roselle (Hibiscus sabdariffa) meal diets

Résumé

In the study, the effects of different dosages of Hibiscus sabdariffa meal diets on the organosomatic indices and histopathology of organs (n=20) of juvenile Clarias gariepinus was evaluated. The fish with initial mean weight and length: 10.94±0.02g and 10.28±0.04cm were stocked in triplicates per treatments. The fishes were fed twice daily at 5% body weight, for 12 weeks. Six isonitrogenous diets containing 40% crude protein were formulated and coded as Hibiscus sabdariffa meal1 (SM1Control), Hibiscus sabdariffa meal 2 (HSM2), Hibiscus sabdariffa meal 3 (HSM3), Hibiscus sbadariffa meal 4 (HSM4), Hibiscus sbadariffa meal 5 (HSM5) and Hibiscus sabdariffa meal 6 (HSM6), respectively. Organosomatic indices such as cardiosomatic index (CSI), Hepatosomatic index (HIS), Renalsomatic index (RSI), Visceralsomatic index (VSI), Cerebrosomatic index (CBSI) and Fat deposit index (FDI) of the fish were measured using standard methods. Histopathological examinations of the organs were carried out following routine laboratory techniques. Data were analyzed using descriptive statistics and ANOVA at á 0.05. The result revealed asignificant differences in all the orgaosomatic indices except VSI within the treatments and control. The histopathological examinations of the liver of C. gariepinus revealed a gradual changes from mild to moderate and severe diffuse hepatic vacuolar degenerations as the concentrations of H. sabdariffa meal diets increased. The intestine showed a mild stunted gastric villi in fish fed HSM4 diet which had the highest growth data not shown. The study revealed that the consumption of unnecessarily high dose of H. sabdariffa for a long period should be taken with caution, despite the improved growth performance observed. Further studies on the effect of processing cum detoxification of the Roselle in fish as an animal model should be undertaken.