Mandarins can be a bit slow, but I think all of them can be trained to eat black worms. Here's how I did it. I turn off all my pumps, shoot a load of worms at one end of the tank to distract and feed most of the fish, then I use my turkey baster to squirt a couple (2? 3? 5? up to you) right in front of my mandarin. The first time I did this, I shot them in her face and it scared the hell out of her so she bolted. Once she came back out to the front of the tank I tried again, more gently. Squirt them in FRONT of her this time so she doesn't get a blast of fresh water in her face, but I was able to put some wiggling worms right in her path. She staired at them all confused for a bit. If they stop moving she will pass them over, but if they keep wiggling she will eventually strike at one. She now welcomes the tip of my turkey baster and doesn't shy away if I accidentally blast her in the face. Because of her, I changed the way I get my worms. Black worms die pretty fast in salt water I now fill a cup with fresh water (rodi) then grab a couple pinches of worms from my worm container and drop them in the feeding container. To feed them I just suck out a few with a turkey baster and spot feed. I made it sound complex, but it's really pretty simple. Key is keeping the fresh water worms in fresh water right up until you squirt them into the saltwater tank to maximize their "wiggle" time.grrrr.....I want a mandarin sooooo bad......lol. im just afraid I wont be able to get it to eat. maybe next time im at my lfs I can ask them to see if one of their mandarins will eat blackworms. I feed exclusively blackworms, so that would be awesome if I could find one that did.