Until recently, all Botia species were wild caught. There have been occasional captive spawnings, but in general, they are regarded as unbreedable without special techniques. The farms that churn them out use hormone injections to get them to do the biz. In the wild they are highly migratory, and nobody is 100% sure at this time what causes them to migrate, or how they decide when they have reached the right place.
I believe the current upsurge in weirdly marked Clowns is a direct result of this intensive inbreeding. The farmed stock also seem weaker, perhaps unsuprisingly.
Sexing is best left to the Botias, I don't think there are any reliable external differences. Stories exist about this or that marking, but usually are based on rumour or heresay.