In my opinion,this group should be all females.
Five small one should be F1 of WC.

According photo 2,it should fat but not sick.

Anus looked huge ,i can guess it should be male or having breeding experience female.

and it doesn't look like a male,so it shoule be a having breeding experience female and she is gravid.

i had some breeding experience including this Species.

the fourth could be male,others should be female.

Sanplec wrote:Here are the new pictures:

according to your new pictures,i think only the NO.6 would be female.

CanadaPleco wrote:Wow, wish I had one like that, its beautiful! How big was it when you got him?

27cm when i got him.

i picked one that had most line in the group.

keeping him for 7 years,now it become 33cm huge.