Sometimes you just never know.
I got these from Eric last summer:
I was a bit disappointed at the time that he only had female seahorses. This is easily figured out by the absence of a pouch below their abdomen:
However, in the last month the same seahorse pictured above has gone through some changes:
So, it appears that I have a male/female pair after all (unless the other female starts developing a pouch too!) My current theory is that they were just too immature when I received them--there's many accounts of seahorses taking up to seven months to fully develop their gender. I cannot, however, find any information on protogynous hermaphroditism in seahorses, so it's doubtful that it actually changed gender.
