I found my gold koi fish can`t entirely unfold its pelvic fin, i once though maybe it not accustomed to the water quality, just needed more quiet time, as for its appetite was always quiet good, but it didn`t work.

    It was always followed by the aboriginal one,  so it overshadow my mind why the aboriginal always targeting this fish? Due to the territory definition or pure bully threat, cause the long time status quo but there is no real hurt so far.

    I resort to the internet and prove the mentioned two predictions may exist, but the true result is food looting.

    I admit that gold one seems with big mouth by nature, so the slow catching aboriginal one got less food than it once had enjoyed, and when it felt hungry, it kept chasing. Maybe that is real reason for pelvic fin problem due to hysterical inmate.

    Now last night i fed the aboriginal one to full and it started to enjoy its life, no frequent harrassment right now.

    So the coexistence seems to buildup at last.