News Animals Perfect Match: Tied contest gives fish no hormone rush By Susan Milius September 7, 2005 at 11:12 am - More than 2 years ago Share this:Share Share via email (Opens in new window) Email Click to share on Facebook (Opens in new window) Facebook Click to share on Reddit (Opens in new window) Reddit Click to share on X (Opens in new window) X Click to print (Opens in new window) Print A male fish produces a burst of hormones as he fights off an intruder. Now, researchers say that this surge isn’t triggered simply by fighting. SAYS WHO? A male cichlid makes menacing gestures to his mirror image as researchers take advantage of his fight with a perfectly matched “opponent.”