Evaluation of water hyacinth (Eichhornia crassipes) supplemented diets on the growth, digestibility and histology of grass carp (Ctenopharyngodon idella) fingerlings

This study was conducted to evaluate the potential of water hyacinth as aquafeed for grass carp (Ctenopharyngodon idella). Fish were stocked in eight glass aquaria at 20 fish per aquaria. Three iso-proteinous diets (30% crude protein (CP)) were prepared with the addition of different parts of sun-dried water hyacinth, that is, whole plant meal diet (WPM), leaf meal diet (LM) and root meal diet (RM), along with control diet. Results revealed significant (P ≤ .05) differences in weight gain and length among treatments. Higher weight gain was observed in LM and lower in RM diets. CP contents of fish fed WPM were significantly higher (P ≤ .05), followed by LM than RM and control diets. Crude fat was significantly higher in fish fed RM followed by LM, while ash contents were significantly higher in control. Nutrient digestibility in the case of CP was significantly higher (P ≤ .05) for WPM, LM and control groups than RM, while fat digestibility was significantly higher (P ≤ .05) in RM diet followed by LM than WPM and control. Histological study showed no significant variations in liver and kidney. In conclusion, LM-based diets were found to be most suitable without any adverse effects on the histopathological disorders in experimental fish.