What is the natural cause that makes fish die?

Question

there are a lots of factors that makes fish die such as water pollution, different pH levels in the water, cause by parasites and also may be cause by natural cause. what is the natural cause that makes fish die?

Answer 1

oxygen deficiency

Answer 2

Apparently many fish are easily stressed this makes them more vulnerable to disease. Stress kills us all, even our fishies!!!!

Answer 3

They get eaten by a larger fish. Seems "natural" enough to me. :D

Answer 4

I just found this out today and found it very interesting.  I was talking to the owner of my local fish store, who knows a lot about fish and has been a great help to me.  Fish can die of a heart attack (which I already knew) or a stroke (new info to me).  Death from both can be very sudden - swimming around, eating fine one minute, and dead or dying the next.

Answer 5

getting too old and other fish eat them

Answer 6

They are eaten, they get to old and catch a disease, or they are attacked by another fish leading to disease.

Answer 7

It is called age.  Most fish have a rather short lifespan.

Answer 8

their little hearts just can't make one last pump of blood from being so old.

Answer 9

They get to old.

Answer 10

It could be too much chlorine water, too much food, or a dirty tank, or a disease caused by the water in the tank.

Answer 11

old age or being killed (hunted,poisoned).

Answer 12

age.......