Hi everyone, I was just feeding my fish when I noticed a large white growth on the back of one of my Corycats, and I became really concerned... It doesn't look anything like ich and I don't know if it's something that might be contagious to my other fish. The fish is swimming around like normal and isn't acting out of the ordinary... in fact it's pretty active. My tank is 20g high at 74.8F, with 5 cory's and 5 danios. I just had my water checked at my local fish store the other day and the lady told me that the parameters were fine. She said it was just the ammonia that was a tad higher than usual, but it was nothing that would harm the fish. I don't have an emergency hospital tank, so I don't have a way to take it out and separate it from the other fish if it is contagious. Has anybody seen this before? I'm kinda freaking out! Here are some pics; sorry for the poor quality/sideways angle.