Hi! Almost all my female guppies are sick now, with the following symptoms: 1. they keep their tail in a clenched position 2. most of them have partially lost their tail, which also shows some white colloring 3. half of them have a shrunken, died out belly, and are rather ghoulish looking But all of my males are fine. How can it be that this disease only hit females? I have also attached some photos. Does anyone have a clue what this could be?