I've got a couple seahorses in my 33g cube, one likes to stay hitched onto things most of the time, but the other is more playful. He'll curl his tail, and ride the slower current up to the filter output, and then ride the strong current of that and the powerhead all the way around, then he'll do it again. It's really fun to watch, and I can only assume he's doing it on purpose, since he can get out of it any time he wants, but keeps coming back for more. For those that have seahorses, do you have any that are playful like that?