Fig. 2. Attack latency of isolated juvenile rainbow trout in repeated 30 min resident/intruder tests performed before (day 0) and 3 and 7 days after feeding the fish with an experimental wet feed supplemented with (A) 1.5 % (experiment 1) or (B) 0.15 % (experiment 2) L-tryptophan (TRP). In both experiments, the control fish were fed the same experimental wet feed but without supplementary tryptophan. Values are means + S.E.M. (N=12 in all groups).