Well just yesterday I bought a small black veil angel and by this morning she had split fins at the top dorsal and split on the same fin down closer to the body. The tank has 3 corey cats, 2 weather loaches, a bristle nose pleco, and an adolecent Clown Knife fish. Now the first thing I though was the clown knife was picking on her, he couldnt eat the angel even if he wanted, so Iv been watching closely and the knife will swim up to it then swim away. Not one bit of aggression! So what the heck is going on? Could it be possible that maybe there to much of a current in the tank or maybe spending to much time by the bubblers, she likes to hid behind them. I guess the fins could have been like that when I got her, she did hide all day yesterday when I brought her home.