Are All Wal Mart Plecos Common Plecos?

[grimlock3000]

I was at Wal Mart (Falmouth, ME) today and stopped by the fish section to see what they had and get some ideas for new fish. About 1 out of every 3 fish at this Wal Mart is dead and still in the tank, no kidding. I saw a fish there that I decided not to buy hoping I can get it somewhere else. The fish had no label.

The Plecos were about 1.5 to 2 inches long, and had very dark diamond shaped bodies. They were almost as wide as there were long, not taking into account the tail fin. Overall, they were the most stubby Plecos I have seen. The bodies were almost black, and they had whitish spikes on their fins. They looked like they had some spiky areas on their bodies as well, between the top and side fins. The spikes looked like what I have seen on much larger Plecos, but never on a smaller one. The fish looks covered in plated areas instead of scales. I have looked all over and not found anything that matches in the pics of Common Plecos. Then again, I have not seen any pictures of really young Plecos either. I would definitely like a Pleco with a more diamond shape that stays relatively small and these looked like they would be appropriate.

Are these just Common Plecos? Or are they something fancy? If I know what they are, I am sure I can find another one at a NON Wal Mart location. Otherwise, I might get a couple and QT them for a long period of time in a seperate tank before introducing any potential Wal Mart tank infection to one of my tanks.

On a side note, how long should I wait before adding Plecos or other catfish to a new tank? I have a 26g bow front tank with Cherry Barbs in it right now. I kickstarted the tank with a used filter sponge from a tank with a much higher bio load. Water parameters after a week have been close to perfect...

[Silurus]

They are almost certainly common plecos. The ones I have seen in large chain stores are almost always a very dark gray to almost black (probably because of the stress).