Now there's a phrase that's probably not gonna be googled a lot. Something few people know is that several species of fish are actually hermaphroditic. In the case of these fish, Psychedelic Wrasses (Anampses chrysocephalus), they all start as females that form a harem under a dominant male. If the male ever disappears, then the dominant female will change sex and become a male.
Protogynous hermaphrodites go from female to male. The reverse is true in protandrous hermaphrodites. I suspect there are some Hawaiian fish that might do that, but you'd have to ask a marine biologist... but there are some recognizeable fish elsewhere that do just that. The most common ones I can think of are several of the clownfish (everyone seems to know them as "Nemo" these days) species. They start as male, and then the most dominant member becomes female as needed - this insures that if two young clownfish find each other they can successfully pair up and mate. Back in my aquarium shop days people would occasionally ask about why one of their clownfish wouldn't grow like the other one, that's the reason.
This group of wrasses was off one of our favorite dive sites yesterday and I got this shot with a bunch of females and the male in the same shot... too bad he's a bit blurry, but his brightly colored face still shows off very well.
Water temp yesterday was 75/76 - Yahoo! It jumped 2-3 degrees the last couple of weeks. We had an unusually early major south swell (been a rough, yet diveable, month) that apparently brought in warmer waters. It was very very flat water conditions the last couple of days, hopefully we're over most of our heavier winter swells.