Wen Growth Problem On A Lionchu Options

[32Bit_Fish]

I was looking at the pics of my goldfish which they were taken several months ago when I first got them.

One of the fish that I bought from pet store, his wen gotten so much smaller. The difference is like day and night. I dont know what happened. I feed him progold in the morning and hikari frozen food at night. A lot of you were telling me that I'm overfeeding my fish, but why his wen gotten so much smaller n there is no wen growth even when I have been overfeeding them? They suppose to be overweight, not the other way around. This just doesn't make any sense to me.

Now I feel like I need to feed more frequent or the other possibility is the seller injected hormone to the wen area try to make a sell.

I bought the fish couple hours after he arrived at the my LFS, so either the breeder or the middle person done something to the fish. Otherwise, I couldn't figure out why this is happening to my fish.

All my fish have lengthen, but the wen growth has been going backwards.

Does anyone have any idea about what I'm talking about?