I have had two ADFs for about 8 months now in a 20 gal long (heated, filtered, planted) with a male betta. Both seem happy and healthy. While at pet supplies plus today, I just had to go through the fish section and I saw they had ADFs in the same small tank as ACFs. I have no experience with ACFs but I was always told that they would eat ADFs, so I felt I had to take the two ADFs. They were skinny, but looked fine otherwise. The employee found a third ADF while trying to catch the two I had seen, so I took that one too. I have another 20 gal (heated and filtered) that is just housing plants and snails and figured I'd put them in there. I fed them before adding them to the tank, so I'm not sure if I just overlooked this or if this somehow happened in the 7 hours I've had them. One frog's foot is whitish, or lacking color. The webbing looks clamped and I noticed what is possibly the bone showing. For lack of a better description, it looks like the foot is dying. Higher up the leg, on the knee area, there's some type of growth that looks like it could be bacterial or fungal. The leg doesn't seem to move much when he swims around, but he is active and eating. Since I added them to the tank I've been watching them, so I don't think this happened since I've had him. My filter intake has a cover on it so their legs can't get sucked in. My gravel is very light, almost white, and I didn't notice the discoloration of his leg until he was floating at the top. I have separated him for now so that no diseases spread. (Excuse the food in the pictures, I fed him after I separated him to make sure he was still eating) Any ideas of what this is and is there anything I can do about it?