Petco rarely gets interesting fish because most are from Fish Farms in Florida. Sometimes we get fish that obviously just jumped over from another tank or pond and blended in, but rarely do you get an interesting species. The assorted groups might yield something, but I don't know African Cichlids well enough to look, and I'm not expert at Corys either.
It doesn't really matter though. Petco sells mostly bread and butter fish. They have a fast turnover rate, and so make more space for more. That is the only real reason I hate retail so much. Sometimes we get in interesting fish, but rarely are people even interested. It's hard to get someone who thinks fish are disposible to buy a 6 dollar rainbow.
Case in point. We have a Yellow Headed Jawfish in our Saltwater tanks. He's been there for at least 4 weeks, but we aren't completely sure when he got there, or how much he is. He hides so well that very few people even notice the guy, and he's almost 4 inches long. We've also got some kind of catfish that is the reaminder of an old shipment, and not one customer has noticed it. Which is nice, since we have very little idea what he costs.
Petco rarely stocks the fish I'm interested in anyway. I just bought a tiny yo yo loach that had been a reminant for a few weeks, that very few people noticed. I love loaches, and with Petco's sometimes fluctuating water quality they have a tendency to die there, so they don't normally order them. And hey their going rate of 5 bucks keeps most regular customers away from them.
Imagine if they stocked dwarf cichlids.
--Mia