So my female guppy has been in the tank for 2 weeks, but her fins are nipped. I've finally observed the culprit.... a tailspot blenny. The poor guppy can't swim anywhere but under the filter. Blenny has claimed holes in the center of the tank, and the guppy isn't allowed anywhere. So my experiment is over, due to jerk blenny.
I might try a Molly or something different colored in the future, in thinking the aggression is from the similar color.
I might try a Molly or something different colored in the future, in thinking the aggression is from the similar color.