Danio-1 gone -2nd sick

Hi,

I had six danio and one became ill fast and died two days ago. Today I
have a second danio with issues. He is swimming stiff and crooked. One
of his eyes has lost it's black color and is a faded grey. He looks to
be developing a hump on his back. Not smooth as in growing bigger but
sticking up like a lump. It looks like he might have bites on his
sides. He's in with other danios and three minnows. He has been
preferring to lay on the rocks but will swim and is eating.

I do have a very active male that chases everyone. Could this male be
attacking the other males so he is the only one among the females?

Watching them I see no outward aggression.

thanks,
carol