Does anyone know the exact dye that is used in Masago? A simple thorough washing of the eggs should be more than enough to knock off any spices/sauces that are put onto the Roe, and a soaking can remove most of the dye.
With how fatty Roe is, I doubt it should be fed as a staple food. So, in the amounts that should be feed (IMO), the minimal dye remaining likely won't have any affect on the fish or tank.
Thoughts?