is my fish sheding

[knifefishfreack]

i have a raphiel catfish for about two years no. He has been fine to about a week ago. Then i saw bits and pices of some sort of shell. half of him got really dark and the other part stayed light. Any one know whats happening

 

[knifefishfreack]

i think there is somthing wrong with him he sticks his head out of the water and goes right across the tank. does he have brain damage

 

[Purple]

my lima shovelnose used to shed his slime coat - stress basically - how's the water conditions and the tank/swimming room for yours ?