My fish is losing scales

Question
I have two goldfish, one is a smaller one who is almost entirely white, and then a beast of a goldfish who is all white(I have treated them for Ich, but it never worked. I just assumed they were meant to be white.)
My little fish is losing scales. Large patches are missing all over his body. My mom thinks it may be my large fish attacking him, or possibly the sucker fish that's in the tank with them. The suckerfish mostly keeps to himself though, i've never seen him latch onto one of the fish(and they've been mean to him at times).
Or it might just be some sickness.
He's fine except for missing scales, but better safe than sorry, right? :)

Answer
Hi Hannah,

Turns out your Mum is probably right. Scale-loss is usually down to either stress and/or bullying.

You say he's in a tank with a goldfish much larger than himself. Goldfish are never territorial, but they are very boisterous when it comes to food. They lack a stomach so essentially their hunger is never satisfied. It's a mistake to house fancy goldfish with bigger species...however, I've done it in the past without any problems, but don't tell the other experts that because they will kill me!

It's unlikely your sucker would have done any damage. Fish like Weather loaches and alike sometimes latch onto goldfish because they mistake their scales for food but this is very infrequent.

I'm assuming you've only the one tank going so things can't be changed. He should be fine once he settles, just watch the bullying, if it is getting out of hand, then maybe you need to move him to another aquarium. However, you could make do for the time being. Just watch them at feeding time and step in if the bigger fish is muscling him out.

Goldfish are fine without their scales. In fact they have three layers of skin anyway. Wild goldfish are brown, commercial varities have the gold layer and then specialised strands have the layer under that which is white, under that there is protective skin. So basically....you shouldn't have any problems!

Good luck!

Tom