TY - BOOK AU - De Silva, Sena S. AU - Perera, M.K. TI - Digestibility of an aquatic macrophyte by the cichlid Etroplus surdtensis (Bloch) with observations on the relative merits of three indigenous components as markers and daily changes in protein digestibility PY - 1983///, CY - University of Ruhuna PB - The Fishery Society of the British Isles N2 - The digestibility of the aquatic macrophyte Hydrilla verticellata by the Asian cichlid, Etroplus suratensis was estimated using three indigenous markers viz. hydrolysis resistant organic matter (HROM), crude fibre (CF) and hydrolysis resistant ash (HRA). In the fodder HROM showed the least variation and HRA the highest. The recovery of HRA in the faeces was always higher than 100% whereas HROM was the nearest to 100%. The total digesti­ bility varied between 34-6% and 51-9%, and the digestibility estimates were higher when HRA was considered as the marker. The overall protein and lipid digestibility varied between 59-2%-70-9% and 65-0%—70-1 % respectively. It is suggested that HROM is a better reference marker in comparison CF and HRA. Daily variation irfprotein digestibility ranged from 51 -2% to 81 -8% ER -