So my 6 corys and my betta have been living happy for 4 months, BUT, "Swimmy" occasionally chased the smallest cory around the tank. Occasionally I would see Swimmy flare up and nip but never on a regular basis.
About a week ago I noticed the small cory was swimming funny. After closer examination I saw one of his pectoral fins was broken. I though it odd but thought maybe he did it when the corys do the day run arounds I see them do. So he has been doing a lot of hiding but today I saw him floating on his side on a plant....and his tail fins were nipped off. Poor little guy!
I will have to see if Swimmy starts on any of the other Corys, but they are all pretty good size.