Need help for sick Banjo Cat

[SimonWoodstock]

I just bought a banjo cat earlier today and when I got home and released him into the aquarium, I noticed a small sort of a indintion almost that looked fuzzy and greyish. Does anyone know what this could be, how it can be treated and if it is something to be worried about?

thanks

[BK]

could it be shedding its skin?

[SimonWoodstock]

Someone told me it could be "grey skin", but anyway it died the day after i put this post on here. Took him back to Pet Depot and got him replaced. The new one i have is doing great though, he is cool to watch swim around. It's a very interesting fish.