Hi! So we've been slowly stocking our 40 gallon breeder. When our cycle was complete, we added four male platys and a bristlenose pleco. A week later we started slowly introducing small groups of cherry barbs. Two weeks later, we had 11 cherry barbs, 1 male and 10 female. A week later, we added 10 ember tetra. This weekend, we took three of our platys to the fish store and came back with a male pearl gourami. Everyone's seemed fine all along the way. This afternoon though, I realized two of our cherry barb are missing the lower half of their tails. Who should I try to pull out? I figure it's either the gourami or that our last platy's gotten bored. I know that tetras can be fin nippers, but the size of the chunk missing doesn't really fit the size of our juvenile embers. Thanks!