Sissy, Petco puts a description and recommendations out there for general knowledge. They have to cover from the complete novice to the most advanced in a generic explanation. All gold fish are the same and should be treated as such, The only thing you want to keep in mind is that new variations and breeds can have weaker resistance to illnesses. Oranda's being probably one of the most fragile due to the head growth, and then the bubble eyes second again due to the large eye sacks that can get injured or are weak at fighting off diseases. What you really want to be on the look out for is fake coloration. You've seen enough goldfish and koi, a dyed fish will stand out like a sore thumb. From the pic I think they are being breed just like a chocolate, blue, yellow, etc. just a color morph that has a maroon/purple hew over a bronze-orange body. Be sure and look for deformed fins, missing gill plates, overly bent backs, and any other deformities. In early stages of developing a new strain many breeders will hold on to some of the nice colored fish that have slight deformities to see how they develop. Of course they are going to hold on to the best of the best for themselves and then sell off all that may have deformities but good color to make them available and known. It's very common that the fancier and newer the strain the more deformities will develop or show up at the retail market. Breeders are going to try and reduce #'s so they can work with the best to make them better. This is why when your buying from a PETSTORE (NO MATTER WHAT COMPANY) you inspect closely and Quarantine your fish. Pet stores buy from dealers that buy in bulk, Bulk buying is usually the culls for someone else. Not that there is anything wrong with them, but these are going to be the fish that have been kept in the most crowded holding tanks, they are the rejects and in many cases aren't kept in the prime tanks or ponds but in massive holding areas until they can get them big enough to distribute.
