I think he has a lot of tetras..at least in one tank. But they are the small kind. Not likely to become fin nippers..
but ya never know.
edit: yeah checkeed his profile instead, he has NEONs in the tank..and you know the pesky things would be floating daily if the parameteres were bad enough to shred senor plecos tail. So it is either something strange hopefully not contagious..something added or the tetras being brave
"Fish! Thank You! Oh, tropical huh? Did you buy a heater? Auuugh!"
Mega-pet stores prolly should not be allowed to sell animals as retail "items".