Thesis (MPhil (Animal Sciences. Aquaculture))--University of Stellenbosch, 2006. / Chemo-attraction and –stimulation facilitate the initial location (olfactory response) and final consumption (gustatory response) of food in the feeding process of fish. Chemo-attractants or chemo-stimulants is therefore generally included in feeds for especially slow-feeding species to help reduce water fouling and to promote feed efficiency and growth rate through improved feed intake. Considering this, a study was performed to evaluate the attraction and stimulation potential of selected cereals and free amino acids in diets for Japanese koi carp (Cyprinus carpio). Results are presented on the comparative evaluation of five cereals (maize, sorghum, wheat, rye and triticale), raw and cooked forms of maize and concentrations of betaine and selected free amino acids (alanine, arginine, lysine and methionine), as well as their additive effect.