used to have three elephant nose's that were handfed, did tricks with pingpong balls, and small hoops! took ages before they got used to the idea! they started being scared around me but i used frozen bloodworms to get them to take food from my hand, soon i just tried putting a "O" shape with my fingers and they began playing by swimming around the loop! that was one of my best memories in fish keeping, sadly they passed away when i went overseas for 2 weeks ): apparently they only ate when i fed them... they didn't like the idea of my family members feeding them... guessed i pampered them too much ;/ currently in the process of training one more though, this new guy's even more shy than the previous trio.
Good luck with your dolphin bro!
mormyrids are pretty entertaining and fun fishes once they warm up to you!