I lost one of my Borleyi Kandango this morning. Last night it was swimming upside down, this morning I found it dead, it had similar silvery patches (scracthes) on its body. The second one seems to have similar silvery patches (scratches) on the body, is this some kind of disease or maybe it's from scratching the body against the rock or crushed coral? Please help me out. I am attaching some pictures. The water parameters seems to be fine.

