That is cool, I agree it is neat to be able to hand feed your fish. My angels and platys will take blood worms from my fingers. It has gotten to the point that any time my hand is in the water, even if it is only for doing water changes my platys are pecking at my hand to see if I have anything for them.
Interesting, pikes in a home aquarium. Big carnivorous fish like that make me think of trying to fish for them rather than caring for them. xP Very cool though, I wish I had aquariums big enough for large lake/river fish like that. Hopefully I'll be able to hand feed my bichirs like you can with those pikes. :D
Be careful I was doing the same thing when I lived in Oregon bought a young pike put him in a 55 the little guy was entirely too fast for his own good. Wound up smacking into the side of my tank and killed himself. I think though the dempsy I had in the tank might have charged him and he was fleeing not entirely sure. Hopefully yours doesn't smack into a wall as mine did.