I feed blackworm to the other critters in my horse tanks and keep hoping they will try them but so far, no success. My mandarins, pipe fish, amphipods (yes, pod!), crabs, serpent stars, polyps, snails, shirmp ... you get the picture, ALL love them but the horses only look at them and don't snick.
I feed only live to my tanks so I keep looking for alternates I would really like to know what the marine worms were as black worms are fresh water and die within a minute of being exposed to saltwater.
"D"