This thread got me thinking. Are there any other male/female fish species that have the more obvious visual and physical markings like BG and HBG?
Yes, California Sheephead comes to mind because of the great difference between males and females:
Male:
Female:
But then just to throw a monkey wrench in things, you have this:
California sheephead can transition from a reproductively functional female to a functional male during the course of a lifespan in response to social factors. Protogynous sex change typically follows the size-advantage model, where gonadal transformation occurs once the reproductive potential of an individual would be greater as a male than as a female. The transitional phase takes between two weeks and several months, and steroid hormone concentrations are thought to be related to sex change due to the total degradation of the ovaries and the appearance of testes. The exact timing of the sexual morphogenesis is suppressed by aggressive interactions with dominant males and triggered by the removal of alpha males. There is a period of reproductive inactivity during gonadal remodeling, and the sex change in this species is unidirectional. In later stages of the transition, fish possibly are functionally male, but maintain an intersexual gonadal appearance.
