You could have feeder goldfish, or possibly minnows. Without knowing species & more info on the bumps, can't really say what this is.
A pic might help.
80 gal FW with 30 gal DIY wet/dry/sump.
9 fancy golds, 1 hillstream loaches, 1 rubber-lip pleco (C. thomasi), 3 SAEs, small school of white cloud minnows, planted.