most of these fish are injected with dye in syringes into the dermis of the fish. It's the equivalent to letting your drunk friend that's never tattooed before ink you. It looks like crap and the lines are horrible. =P I could see it causing issues as it's not natural. Pretty sure the ink gets into the blood system because the people doing it have no regard for the fishes safety, and probably stab the **** out of the fish. That has to go through the body, liver, kidneys, etc. I could see how this could cause sterility. Tattoo ink does not generally enter your blood stream since the ink settles into the dermis and not below it. I think the ones that are completely dyed and dont have "smiley faces on them" are dye baths. Stripping off the slimecoat is asking for a very sick fish and death.
