I wouldn't worry too much unless it is the first spawn. If it is they may end up eating their own babies or not doing anything against your other fish trying to eat them.
They make a good food source for your other fish though. Just let them sort it out or they can overrun that 55 gallon, the weak will die off, you want to only keep the strong ones anyway. Also if you are worried about your filter sucking them up I would put an old net or a sponge over the intakes. Most lfs probably won't take them for credit. Might want to find someone on here that can use them as food tho or post a craigslist ad when they get almost an inch long.
Convicts are fun!