Pheromonal control of aggressive display in siamese fighting fish (Betta splendens).

Male Siamese fighting fish displayed and respirated from the surface more frequently in water containing secretions collected from non-displaying male conspecifics than they did in clean water. Secretions collected from males given the opportunity to display to a mirror for 16, 30, or 45 min. did not affect display activity. However, secretions collected from males allowed to display to a mirror for 16 min. produced an increase in respiration rates. Secretions collected from males which had been stressed by electric shock resulted in decrements in aggressive display. Taken together, results of these experiments suggest that male Siamese fighting fish secrete substances which affect mirror-induced aggression and respiration rates.