Just bought 4 multis a few hours ago for my 10 gallon, pictured below. I asked for an obvious male, and then three of the smallest ones the worker could grab - hoping that I’d hit on 3 females (there didn’t appear to be multiple generations in the tank). When introduced to the tank, the male instantly paired with a female in the back left corner, and the two other small multis settled in the right shellbed. As the fish started adventuring, it became clear that one of the small multis was not allowed into either of the shellbeds. The obvious male was fairly tolerant of it, but not the two other small multis. This fish has now taken refuge to the top of the tank. I don’t think the other dominant small multi is a male, as the obvious male has now begun to enact the same behavior as he did with the other female. I always thought males were more protective of their shellbed, and often had multiple females to spawn with? Should I reduce the size of each shellbed and make a third in the middle for the loner?