My silver dollar fish died today morning with yellow spots on belly. Please tell me what happened to my fish. I have 10 gallon fish tank with 4 guppies 4 danio 2 silverdollar 2 gold fish 1 pleco.

How long has the tank been set up? Have you tested the water since the silver dollar died? If so, what were the readings?

I'm not sure what the yellow spots could be, but oftentimes when fish die it's due to water quality, and as your tank is overstocked it's possible there was a buildup of ammonia and nitrites, which are toxic to fish.