I have 3 pearl gouramis, 2 females and 1 male. For the last week one of the females has been pointing vertically towards the top of the water close to the surface. At first I thought she was dying, but whenever I come near her she straightens up to her normal swimming pattern. However, as soon as I walk away she resumes her vertical swimming position. Sometimes she almost swims at a 90 degree angle and at other times it's a 45 degree angle. Does anyone have any thoughts about this? I've the trio for about a year.