dead fish question

so heres a question. If you find a fish dead floating on the top of the tank, or nose down in the sand at the bottom with his tail up does it give any clues to the reason it died? or do different species of fish tend to float/sink? - hope this question makes sense.

 

I generally find that if the fish is floating, it's been dead for at least 8 or more hours. Usually my fish die and immedietly fall to the bottom.

 

hi guys. Yeh Zoom is right. Floating fish has normally been dead for longer. Bacteria working inside the fish cause gas buildup which in turn lifts the fish to the surface. It could sink again at a later stage of decomposition when the gas escapes. Regards, Marco

 

Thanks guys - I never knew that. It is strange though, last friday we got 2 new fish for the tank in the morning. We went out late afternoon (all fish were happy and normal) and got back in the evening to find on of the new fish floating and one of the old fish (old fish as in we'd had him for 3 weeks) dead on the ground. Very sad. Everyone else was ok and still is. We definately weren't away for so many hours. Thought it might give me a clue as to why they died.