GAWK! Never noticed anything during quarintine. This guy has been in my tank for 3 months and I noticed something on his tail about 2 days ago but it looked like one of those teeny tiny snails so I let it go and would just keep an eye on it. He didnt really come out much yesterday. I noticed today it has grown and looks like it has spread from his tail fin to the one on top also. (there is no white on his front fins, that is coraline algea you see in the photo). No other fish is exibiting any spots. (but I plan to just treat them all if possible.) There is no coral in my tank, it is pretty much fish,CUC, live rock and sand, and one rock anemone. What in the world is wrong with this lawnmower blenny and what do I do to treat him??