manderians are rather specific in their diet....copepods/amphipods(maybe frozen brine/mysis)....try a 6-line wrasse for munching bristle worms.....mine had 'em under control ... that is until he went for an extended carpet surfing expediation.....*_^
i saw my manderin eat a bristle worm once. i don't think he liked it very much!!! he spit it out and didn't close his mouth for about a half hour or so!!!OUCH!!