What was that last one? D:
Um... Male seahorses are the ones that get pregnant. That's the only interesting thing I know. I should really read up on some of that stuff.
Isn't there a fish that can change its gender? ... I think there is. And a frog. Then there's the fact that Bluebirds aren't really blue. I guess I do know some weird things. The strangest has to be that gender-changing fish, yep.