I recently stocked my new 180 litre with a few GBR, otos , cories and some blue rainbow fish. Got back home and acclimated in bag for 30 mins or so, after releasing everything into the tank I noticed one of the rainbows which seems to be a different species has had his Gill area ripped and is sort of loose. He seems to be the most active of the bunch which has led to him being picked on a bit by the other rainbows ( I don’t know if this is what caused the injury ) but seems ok . I’m no expert with injury’s or anything so any help will be appreciated. Also will attach pictures, as you can see it is only one side which is like this, could it be parasites or is it a scale wound ?