So I've been using nutramar frozen prawn roe at work and deciced to bring some home. I have not seen the ones at work eating it, but my spotted mandarin definitely came over and fed twice. So I will try sweetfish roe, bigger, but can only be bought fresh. This is good as she was going to have to live in my 40 gal. for a week or two while my 75 is moved and remodeled. Plan on bringing home live brine, trying cyclopeezeand maybe arctipods(they claim mandarins will eat it).