Nice save!! The closest indigestible item in any of my fishes tummy was a rubber band... Sorry if my grammar is wrong... Anyway, my red belly pacus thought that rubber bands are worms... lol I watched them try to swallow the rubber bands before but I managed to get it out before they entered the body...There was a case however one day I was admiring my fish and all of the sudden i saw a rubber band sticking out of my pacu's anus!! I immediately pulled it out gently and there were no side effects... The fish was perfectly fine even though I pulled a 4" rubber band out out through its anus....