For my case, they are not fry but all adult guppies. 1 more is dead today leaving 3. I once got 2 fry & both of them disappeared. Of course the reason is I left them in the main tank. I think 1 more adult guppy is dying. I think I won't buy anymore guppy until the dying stops. I think this disease is not going to stop until all my guppies are died. Giving up my hope oredy. Some of these guppies were with me since I set up my tank. Really sad.