I had 4 platies and 5 danios but there are only 1 platy and 4 danios left. mysteriously, they die in the same manner, like sinking to the bottom of the tank and resting there. I was wondering if they had the same disease that caused them to die that way, and now I have another platy that is looking like it is going to die soon, just like the other fishes die as I stated just now.
Or perhaps they just died of old age? I don't know. My platy shown in the image below is about 2 years old.
The Platy below in the image has died