Behavioural responses of glass eels (Anguilla anguilla) towards amino acids

The behavioural responses of glass eels of Anguilla anguilla towards amino acids were investigated by binary choice experiments testing different concentrations of 14 L-amino acids in fresh water and salt water. Glass eels responded to solutions of individual amino acids down to a concentration of 10⁻⁸M, 10⁻⁹m. Media of different salinities influenced the responses. In freshwater, gln and thr were strongly attractive; asn, ala, met, glu and ile induced significant avoidance; gly elicited multimodal reactions depending on concentrations; his, lys, phe, val, leu and asp hardly influenced behaviour. In salt water, only gly, asn and lys significantly influenced the behaviour of the glass eels.