SPONTANEOUS BEHAVIOR, TRAINING AND DISCRIMINATION-TRAINING IN GOLDFISH USING CHEMOSENSORY STIMULI

The present behavioural experimental paradigm made use of the responsiveness of goldfish to natural and non-familiar chemosensory stimuli in the context of feeding. With the exception of Tubifex food extract, which was spontaneously preferred, goldfish exhibited no spontaneously recordable response to low concentrations of the stimuli tested. Training experiments using non-familiar stimuli (amyl acetate, alpha-ionone, beta-phenylethanol, 10(-6), 10(-7) M) required 2-3 months of daily training prior to the animals reaching a 70% positive response level for discrimination. This discrimination was dependent upon a functioning olfactory system as no responses were recorded after bilateral exclusion of olfaction, e.g. dissection of olfactory nerve or olfactory tracts. Amino.acids (Ala, Arg, Gln, Gly, Lys), more natural stimuli than those listed above, were preferred when applied at concentrations < 10(-5) M. Goldfish were able to discriminate amino acid odours applied at 10(-6) or 10(-7) M, but these stimuli elicited no spontaneous response below 10(-5) M. Ten to twenty reinforcements were sufficient to achieve discrimination between amino acids, which again was eliminated after bilateral exclusion of olfactory pathways. In contrast to the 4-week period for long-term memory to non-familiar odours, long-term memory for amino acids lasted at least 3 months.