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I would bet that you will lose several once the fish start forming pairs and staking out territories. Unless the tank is so densely planted that you can't see into it, I would not have more than 2 fish per square foot (900 sq. cm). In a 55, that would be 5 or 6 pairs maximum.
If you plan to keep all in the tank anyway, may I suggest that you put some floating tubes (3"/7.5 cm lengths of 1"/2.5 cm diameter black plastic pipe work well) in the top of the tank? Fish that don't have a territory will hide in the tube "caves", out of sight of the territorial pairs. They can also be more easily removed from the tank by netting the tubes.