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?

[32Bit_Fish]

Sorry, I probably need to be alittle more informative in my post.. I should give a little specs of my set up and stocking info before posting the problem.

I have a 38 G barebuttom tank with three 5" lionheads. They have been in my tank for the past 3 months.

There are two HOB Power filters running on the tank, each of them has a water turn over rate of 300GPH, so total of 600 GPH turn over rate, that equivlent to 10x+ turnover rate filtration.

I feed goldfish dry pellet (Progold that are well know high quality goldfish food in U.S) in the morning and I feed Hikari Frozen bloodworm, brineshrimp and Mysis at night. I feed twice a day during weekdays and three times a day during weekend.

I do 80-90% w/c twice a week and nitrate level kept at constant of 7 PPM.

My questions are am I overstocking? have been feeding proper food? need more w/c due to dirty water?

I dont see I have any of the problems/possible causes that you mentioned in your post. That's why I'm very confused. I am hoping I have been doing something wrong to cause this problem, so I can correct it.

But I couldn't find any at this point.