DESCRIZIONE
Disclosed is a growth stimulant for fish or a growth stimulation method for fish. The growth stimulant for fish may be a preparation comprising histidine as an active ingredient. The growth stimulation method for fish may be a method comprising administering histidine or the growth stimulant to a fish. The fish may be any one, preferably a fish belonging to the family Carangidae (e.g., amberjack, horse mackerel) or a fish belonging to the family Scombridae (e.g., tuna, bonito, mackerel), more preferably a fish belonging to the family Carangidae.