My fish died suddenly today?

Question

Today, I found one of my fish belly-up in my tank.

When I took him out to have a look, he was slightly sticky and was slimy, like a film was on him. Also, his scales were white/cloudy.

I tested the water, and it was fine, the only thing was there was some algae on the sides of the tank. My other fish are fine.

I got him and he looked like he was fully grown, and I've had him about a year now.

Any suggestions on what may be the cause?

Thank you very much anyone.

Answer 1

looks may fool you. My pey fish died the day i got him because of old age and he looks fine. Other than that, your other fish might have ate him

Answer 2

it may have been of old age or some disease

Answer 3

slimy film, pale in color. sounds like it definitely was sick from  a disease called ick. fish get it from stress. you can use a anti ick solution at the first signs of it and Aqua plus is great to use for water changing

Answer 4

well if u didnt feed it how its sopoused to be feed then that my have been the problem becaz it was a over sized fish