I've been keeping 2 young koi in an aquarium for a year now. They've grown bigger and accustom to me. Their tank is about 55-60 gallons, and I live in the northeast. They were from the same shop and same breed, and they also look similar so they're most likely siblings. But one has grown bigger than the other and eats more aggressively. The smaller one has recently been acting more skittish, and panics a lot.
In a result I think it may have injured its scales from the decor. I heard scales heal pretty quickly so I want to make sure I might be overreacting. But if it's not the case, I set up a quarantine tank next to the main just incase. The wounds however, have made the lager koi chase the smaller one more than usual-even biting the other's fins and the area of the wounds. They are probably too domesticated to shift to a pond, but I've also been planning to build one next year.
So are these injuries serious (images)? And can an aquarium Koi shift to a pond koi?