hi! recently my blackfin cory cat has grown a noticeably sized white silky lump on his head, which ive assumed to be a fungal infection. i just went to my LPS and picked up some remedies and aquarium salt. after siphoning, changing water, and adding the different solutions, i realized the guy with the white lump has significantly smaller fins. his caudal(tail) fin is much smaller than his tankmates, along with his dorsal. the only other mates he has are 3 gold tetra and 2 other same species corys. there is no red pigment or discoloration of any sort near the two fins. besides his fungal infection, i have no idea whats happening to him. from my research, ive ruled out both fin rot and hostile/nippy tank mates. all help is appreciated! ALSO: all fish are moving (as far as i can tell) happily and normally.