I got a pair of sunset fire platies on july 17 from a healthy tank and about the second day i noticed a mark on the male's posterior half- starting from the top of the fish and going vertically down to about halfway down it's body. it is red and looks kind of like a scratch. it is not raised and has no irregular spots on it. i am wondering if this is a marking that the fish was born with, or an injury, or a scar, or an ulcer or symptom of a disease. please inform me if you have any similar experiences or know what this may be.
