I don't think you will find breeder that breed oto. Some hobbyist may find 1 or 2 oto baby, but no where close to professional breed to sale. I believe I saw a oto baby in my 45g community tank however due to it is heavy planted, I only saw it once. However I can't find any record about oto breeding online, and most information state oto are wild caught. I guess if you want to successful breed the oto, you need good water quality, plenty food, plant cover and no predator to eat the egg and baby.
The trick to buy oto form store is wait for a week or 2 if the oto just arrive. (Which will be hard to do as they are high in demand.) If the store place the oto in a clean tank without piece of zucchini allow them to feed on than the oto most likely going to die due to starvation.
Or
Purchase from Petsmart as they offer 2 weeks grantee, usually if the oto make 1 week mark than usually means they will survive in your tank.
The trick to buy oto form store is wait for a week or 2 if the oto just arrive. (Which will be hard to do as they are high in demand.) If the store place the oto in a clean tank without piece of zucchini allow them to feed on than the oto most likely going to die due to starvation.
Or
Purchase from Petsmart as they offer 2 weeks grantee, usually if the oto make 1 week mark than usually means they will survive in your tank.