I found one of my ghost shrimp dead last night before I did my water change. I had noticed that since I changed to the black sand a couple weeks ago that one of them was a lot whiter than their normal brownish clear color. I didn't think a whole lot about it thinking that the shange to black sand from the play sand might be causing the color change. Is it normal for them to do this before they die? How long do ghost shrimp generally live? I got him back in January.