Effect of supplementation of L-tryptophan to different activation mediums (NaCl and NaHCO3) on the sperm motility (A), its duration (B), fertility (C) and hatching rate of eggs (D) of O. mykiss (n=6). Different letters show differences between treatments (p<0.05). T1; 0 mM, T2; 1 mM, T3; 2 mM, T4; 3 mM, T5; 4 mM, T6; 5 mM.