I'm sure that's not a silver. Mouth is too big. Could possibly be a hybrid, but I doubt it, because of where it showed up. Like Conlin said, most likely came in as a release from the live food trade or as acontaminant in with catfish. Either way, most likely directly from aquaculture, not from the wild. That alone makes it a bighead, because there are not any silvers or hybrids in aquaculture.