Males in the groups became dimorphic from the rest of the group as the groups matured. Professor Ohm conducted an experiment by removing the males as they appeared, and noting how long it took for another male to mature. He found that when he left the initial male in the group, no other males appeared. When he removed a male, no matter how long he left the male in the tank after it had matured, the most aggressive female would become the next male. No tanks had two males develop at the same time.
Proteandrous hermaphrodites are the opposite of protogynous hermaphrodites.
In proteandry all of the fish are born male and later turn into females. The most noted example of this group are the marine anemone fishes. This sex change was discovered by professor Hans W. Fricke while studying the anemone fish Amphiprion bicinctus in the Red Sea. Professor Fricke was studying the complex social organization of anemone fish. This species lives in large groups in a symbiotic relationship with a sea anemone.