The carp Cyprinus carpio belongs to the traditional and special inhabitants of the world’s freshwater aquac-

Taste response of the yearlings of carp Cyprinus carpio of 9–12 cm in length to 21 free amino acids (L = stereoisomeres) and classic taste substances is ascertained by in testing behavioral methods. It is found that these compounds can be divided by their taste properties into groups of substances that are highly attractive (cysteine, proline, glutamic and aspartic acids, alanine, glutamine, citric acid, calcium chloride), neutral (histidine, lysin, leucine, tyrosine, glycine, asparagine, isoleucine, norvaline, sodium chloride, saccharose) and deterrent (tryptophane, arginine, threonine, methionine, phenylalanine, serine, valine). Threshold concentrations are determined for the most attractive substances. It is estimated that the absolute quantity of the substance in pellet which is sufficient for stimulating a significant taste response is 4.27 and 3.39 μ g or 3.53 × 10 –10 and 1.77 × 10 –10 mole for cysteine and citric acid. Positive correlation between palatability of pellets and the duration that are retained by fish in the oral cavity is shown. The anosmiating of fish did not cause any changes in the features and intensity of fish gustatory response, nor in range of effective concentrations. The relationship between the palatability of amino acids and some of their structural features, and the physiological requirements of carp for them, is considered. A hypothesis of the zonality of the intraoral gustatory buds sensitive to different types of substances is made.