fungus??

I recently lost 2 serpae tetra. One died after before I noticed any symptoms, the other appeared to be injured around it's mouth area. Now one of the remaining serpaes seems to have a whitish area in front of his dorsal fin. Could this be a fungus? Or something else? It is not specks like ick, nor yellowish like velvet. I can try to get a picture, but my camera isn't very good and the serpaes are very quick.

Oh yeah... other than the spot, the fish is acting normally. No other fish are exhibiting symptoms.